Biomolecules - Class 11 Biology - Chapter 9 - Notes, NCERT Solutions & Extra Questions
Renews every month. Cancel anytime
Your personal doubt-solving assistant
Chatterbot AI gives you 100% accurate answers to your questions in an instant.
Extra Questions - Biomolecules | NCERT | Biology | Class 11
Which of the following statements is true?
A) Keratin is important in the sensation of touch.
B) Keratin contributes to skin color.
C) Keratin helps waterproof and protect the skin.
D) Keratin absorbs ultraviolet radiation.
The correct answer is C. Keratin helps waterproof and protect the skin.
Keratin is composed of dead, flat cells known as epithelial cells and specialized cells called keratinocytes. These cells surround our bodies, providing a barrier that protects against pathogens and prevents them from entering the skin. A critical protein, keratin, binds these cells together and secures them to the underlying layer, the dermis.
In the diagram of pBR322, which of the following is true about the components?
A. rop - reduced osmotic pressure
B. EcoRI, BamHI - Selectable markers
C. $\mathrm{amp}^{r}$ - Antibiotic resistance gene
D. Ori - Original restriction enzyme
The correct option is C. $\mathrm{amp}^r$ - Antibiotic resistance gene. Below is a summary of the main components of the E. coli cloning vector pBR322:
$\mathrm{amp}^r$: This stands for antibiotic resistance gene. It provides the bacteria with resistance to the antibiotic ampicillin, allowing only the transformed bacteria (those carrying the $\mathrm{amp}^r$ gene) to survive in media containing ampicillin. This is crucial for selecting and identifying transformed cells in genetic engineering procedures.
ori: This represents the origin of replication. It is a sequence in the plasmid that allows it to replicate independently within a bacterial cell, ensuring that each cell division passes the plasmid to new bacterial cells.
rop: This gene codes for the Rop protein which helps in stabilizing the interaction between RNA I and RNA II complex, enhancing plasmid copy number control.
EcoRI and BamHI: These are not selectable markers but restriction enzyme sites. They are specific sequences recognized by the corresponding restriction enzymes, which can cut the DNA at these sites during cloning procedures.
Therefore, the components of the pBR322 plasmid play different roles with option C correctly describing the $\mathrm{amp}^r$ as an antibiotic resistance gene.
Peptidyl transferase
A Is a $23 \mathrm{~s}$ rRNA.
B forms peptide bonds.
C Component of ribosome.
D All of these.
The correct answer is D All of these.
Peptidyl transferase is a component of the ribosome, specifically located in the 23S rRNA, and it is responsible for forming peptide bonds during protein synthesis.
"What are steroids, and how do they differ from other derived lipids?"
Steroids are a specialized category of derived lipids that play significant roles across various species of animals and are unique in that they do not contain fatty acids. The structure of steroids consists of a four carbon ring system which is instrumental in various biological processes such as constituting the components of cell membranes, thereby influencing the membrane fluidity.
Differences with Other Derived Lipids:
A crucial distinction lies in the R-group attached to the ring structure, which varies significantly compared to other lipids, impacting the properties and functions of the steroids.
The characteristic four-ring structure of steroids sets them apart from other lipid derivatives. This structure is exclusive to steroids, emphasizing their unique chemical and biological identity.
The boiling point of a solution made by dissolving 12.0 g of glucose in 100 g of water is 100.34°C. Calculate the molecular weight of glucose; Kb for water = 0.52°C/m.
(A) 183.5 g/mol (B) 283.5 g/mol (C) 383.5 g/mol (D) 73.5 g/mol
The correct choice is (A) 183.5 g/mol.
To determine the molecular weight of glucose using its boiling point elevation, we can use the formula: $$ M_{\text{glucose}} = K_b \left(\frac{w_{\text{glucose}}}{w_{\text{water}} \Delta T_b} \times 1000\right) $$ Where:
$K_b = 0.52 , ^\circ\text{C/m}$ (ebullioscopic constant of water)
$w_{\text{glucose}} = 12 , g$ (mass of glucose)
$w_{\text{water}} = 100 , g$ (mass of water)
$\Delta T_b = 100.34^\circ\text{C} - 100^\circ\text{C} = 0.34^\circ\text{C}$ (change in boiling point)
Plugging values into the formula provides: $$ M_{\text{glucose}} = 0.52 \left(\frac{12}{100 \times 0.34} \times 1000\right) \approx 183.5 , \text{g/mol} $$ Thus, the molecular weight of glucose is calculated as 183.5 g/mol, aligning with option (A).
Glycolysis is also known as:
A) HMP Pathway
B) EMP Pathway
C) Hatch and Slack Pathway
D) Glycolate Pathway
The correct answer is B) EMP Pathway.
Glycolysis, a central metabolic pathway for glucose breakdown, is also known as the EMP pathway. This name acknowledges the scientists Embden, Meyerhof, and Parnas, who detailed the process. Therefore, the pathway is often referred to by their initials, EMP.
How much sugar will be required if each person on Earth is given 100 molecules of sugar? The population of the Earth is $3 \times 10^{10}$.
(A) $170.43 \times 10^{-10} \mathrm{~g}$
(B) $170.43 \times 10^{-11} \mathrm{~g}$
(C) $340.86 \times 10^{-11} \mathrm{~g}$
(D) $340.86 \times 10^{-10} \mathrm{~g}$
To solve the problem, we need to determine the total mass of sugar when each person on Earth receives 100 sugar molecules, knowing the population of Earth is $3 \times 10^{10}$.
First, calculate the total number of sugar molecules required: $$ \text{Total number of sugar molecules} = \text{Population} \times \text{Molecules per person} = 3 \times 10^{10} \times 100 = 3 \times 10^{12} \text{ molecules} $$
The molecular weight of sugar (sucrose, C12H22O11) is about 342 g/mol. Using Avogadro's number, which states that $6 \times 10^{23}$ molecules of any substance weigh equal to its molecular weight in grams, we can find the weight of $3 \times 10^{12}$ sugar molecules.
Setup the proportion based on the relationship Avogadro’s number provides: $$ 6 \times 10^{23} \text{ molecules of sugar} = 342 \text{ g} $$ $$ 3 \times 10^{12} \text{ molecules of sugar} = x \text{ g} $$
Solve for $x$: $$ x = \frac{3 \times 10^{12} \text{ molecules} \times 342 \text{ g}}{6 \times 10^{23} \text{ molecules}} $$ $$ x = \frac{3 \times 342}{6 \times 10^{11}} \text{ g} $$ $$ x = \frac{1026}{6 \times 10^{11}} \text{ g} $$ $$ x = \frac{1.026}{6} \times 10^{-9} \text{ g} $$ $$ x = 1.71 \times 10^{-10} \text{ g} $$ $$ x = 170.43 \times 10^{-11} \text{ g} $$
The mass of sugar required is then 170.43 x $10^{-11}$ grams. Therefore, the correct answer is:
(B) $170.43 \times 10^{-11} \mathrm{~g}$
Amino acid chains built by the ribosomes move to the:
A) Golgi apparatus
B) Lysosome
C) Endoplasmic reticulum
D) Mitochondria
The correct answer is C) Endoplasmic reticulum.
Amino acid chains, which are synthesized by the ribosomes, advance to the endoplasmic reticulum (ER). The ER is crucial as it comprises special mechanisms for folding these amino acid chains. Additionally, it functions as a critical component in the cell’s internal transport system, facilitating the movement and processing of these proteins throughout the cell.
"What are lipoproteins?"
Lipoproteins are biochemical assemblies tasked with the transport of hydrophobic lipid (fat) molecules in aqueous environments like blood or extracellular fluids. These structures consist of a single-layer phospholipid and cholesterol shell. The hydrophilic (water-attracting) portions of this shell orient outward towards the water, while the lipophilic (fat-attracting) portions face inward, encasing the lipid molecules.
Apolipoproteins, embedded within the membrane, play crucial roles in stabilizing these complexes and defining their functional identity, which governs their specific roles and destinations within the body. This arrangement makes lipoproteins effective at emulsifying fats, enabling their dispersion and transport in water-based environments.
Lipoproteins include a variety of crucial biological components such as enzymes, transporters, structural proteins, antigens, adhesion molecules, and toxins. They are commonly identified in the plasma as distinct particles like HDL, LDL, IDL, VLDL, and ULDL (chylomicrons), categorized by their density and size—factors that are inversely correlated with their behavior in plasma water.
These lipoprotein complexes are essential for transporting fats across all extracellular waters, including the bloodstream, where they act as emulsifiers. Specific lipoprotein subgroups are key contributors to conditions like atherosclerosis. Additionally, these complexes encompass the transmembrane proteins found in the mitochondria, chloroplasts, and bacterial cells.
Which of the following statements is/are correct about zymogen?
A. It is the inactive form of an enzyme.
B. It is a precursor to the enzyme.
C. It is the form in which many enzymes are secreted.
D. All of these.
The correct option is D. All of these.
Zymogens serve multiple roles related to enzymes:
Inactive form of enzymes: Zymogens exist in an inactive state until they are activated by specific changes in the environment or by other molecules.
Precursors to enzymes: They are the initial forms from which active enzymes are derived.
Secretion form: This is the form in which many enzymes are initially secreted before being activated.
In conclusion, zymogens embody all these characteristics, making option D the correct choice as it encompasses all the given statements.
Microtubules are absent in:
A. Mitochondria B. Centriole C. Flagella D. Spindle fibers
The correct answer is A. Mitochondria.
Microtubules are found in the cytoplasm of all eukaryotic cells and are crucial components of several specialized cellular structures such as cilia, flagella, basal bodies, centrioles, astral rays, spindle apparatus, and chromosome fibers. However, mitochondria do not contain microtubules.
In the process of digestion, the enzymes '$X$' and '$Y$' at locations 'A' and 'B' are such that '$X$' converts maltose into glucose and '$Y$' converts peptides to amino acids. Identify $X$ and $Y$.
A. Trypsin and pepsin
B. Maltase and peptidase
C. Peptidase and maltase
D. Trypsin and lipase
The correct option is B. Maltase and peptidase
Maltase is an enzyme specifically tailored to break down maltose into glucose units. Maltose itself results from the enzymatic breakdown of starch by salivary and pancreatic amylases.
On the other hand, peptidase (also known as peptidase) is pivotal in concluding protein digestion by converting peptides into amino acids. This process complements the initial stages of protein digestion carried out by enzymes such as pepsin in the stomach and trypsin in the small intestine, which break proteins down into smaller peptide chains.
Options like trypsin, pepsin, and lipase, mentioned in other choices, focus on slightly different aspects: trypsin and pepsin also deal with proteins but do not directly yield amino acids, while lipase concentrates on fat digestion.
Compound lipids are formed when lipids combine with other groups, such as glucose and proteins.
A) True
B) False
The correct answer is A) True.
Compound lipids include lipoproteins, which are formed through the combination of lipids with other molecules, such as proteins. This example supports the notion that lipids can indeed bond with other groups to form more complex molecules.
Which of the following statements are correct about the utilization of carbohydrates in our body? I. A part of glucose is utilized for the production of ATP. II. A part of glucose, fructose, and galactose is converted to glycogen and stored only in the liver. III. Glucose is broken down to yield glycogen subunits. IV. Some glucose is also utilized in maintaining the blood sugar level.
A. Only statement I is correct.
B. Statements II and III are correct.
C. Statements I, II, and IV are correct.
D. All are correct.
The correct option is C. Statements I, II, and IV are correct.
Statement I: Glucose, a simple sugar, is a primary energy source where it's utilized for the production of ATP (adenosine triphosphate), which is essential for carrying out various cellular processes.
Statement II: Glucose, along with fructose and galactose, can be converted into glycogen, a storage form of carbohydrate, which is stored both in liver cells and muscle cells, not exclusively in the liver.
Statement IV: During periods when blood sugar levels drop, glycogen stored in the liver is converted back into glucose, which is then released into the bloodstream to help maintain normal blood sugar levels.
However, Statement III is incorrect as glucose is broken down to yield energy or converted into glycogen for storage; it does not yield glycogen subunits. Instead, glycogen is broken down into glucose subunits when needed.
"The helical structure of a protein is stabilized by:
A) Ether bonds B) Peptide bonds C) Dipeptide bonds D) Hydrogen bonds"
The correct answer is D) Hydrogen bonds.
The α-helix structure in proteins is primarily stabilized by the formation of hydrogen bonds. These hydrogen bonds occur between the amide groups within the same peptide chain. Specifically, the hydrogen (H) of the NH group from one amino acid forms a bond with the carbonyl oxygen (O) of another amino acid, typically the fourth one ahead in the sequence. This consistent pattern of bonding maintains the characteristic right-handed coil of the α-helix, effectively holding the helix structure in position. Hence, hydrogen bonds play a crucial role in the stability of the helical structure in proteins.
For a clear understanding, consider the interaction where: $$ NH \text{ group of amino acid (n) is bonded to } C=O \text{ of amino acid (n+4)} $$ This contributes to the overall stability and integrity of the protein's secondary structure.
$18 \mathrm{~g}$ of glucose ($\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6$) is present in $1000 \mathrm{~g}$ of an aqueous solution of glucose. The molality of this solution is:
A) $0.1 \mathrm{~m}$
B) $0.5 \mathrm{~m}$
C) $1 \mathrm{~m}$
D) $1.1 \mathrm{~m}$
The correct answer is A) $0.1 , \text{m}$
To find the molality of the solution, we first calculate the number of moles of glucose. The molecular weight of glucose ($\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$) is calculated as follows:
$$ \text{Molecular weight} = (6 \times 12) + (12 \times 1) + (6 \times 16) = 72 + 12 + 96 = 180 , \text{g/mol} $$
Given that the mass of glucose in the solution is $18 , \text{g}$, the number of moles of glucose is:
$$ \text{Number of moles} = \frac{\text{Mass}}{\text{Molecular weight}} = \frac{18 , \text{g}}{180 , \text{g/mol}} = 0.1 , \text{moles} $$
Molality is defined as the number of moles of solute per kilogram of solvent. Since the solution's total mass is $1000 , \text{g}$ which is predominantly water, and assuming the solution's density is close to water, the mass of the solvent (water) is approximately $1000 , \text{g} = 1 , \text{kg}$. Thus, the molality of the solution is:
$$ \text{Molality} = \frac{\text{Number of moles of solute}}{\text{Mass of solvent in kg}} = \frac{0.1 , \text{moles}}{1 , \text{kg}} = 0.1 , \text{m} $$
Therefore, the molality of the glucose solution is $0.1 , \text{m}$.
Energy released during respiration is stored in the form of ATP or:
A) Adenosine Triphosphate
B) Adrenaline Triphosphate
C) Adenosine Diphosphate
D) Adenosine Tetraphosphate
The correct answer is A) Adenosine Triphosphate.
Adenosine Triphosphate (ATP) is the molecule in which energy released during respiration is primarily stored. ATP is essential for transferring and storing energy in cells, making it crucial for many biological processes.
Which of the following options is a secondary metabolite?
A. Lectins
B. Curcumin
C. Gums
D. All of these
The correct option is D. All of these.
Metabolites are molecules that participate in metabolic reactions within a cell. Metabolism itself encompasses all the chemical reactions occurring in the body, which can be categorized into anabolic reactions (those requiring energy input for synthesis) and catabolic reactions (those that release energy by breaking down substances).
Metabolites are further divided into primary and secondary metabolites:
Primary metabolites are essential for the growth and development of organisms. These include substances like carbohydrates, proteins, lipids, and nucleic acids.
Secondary metabolites, in contrast, are usually involved in defense mechanisms and stress responses. Examples of secondary metabolites include pigments like carotenoids and anthocyanins, alkaloids such as morphine and codeine, terpenoids, essential oils, toxins like ricin (from the castor plant), lectins (like concanavalin A), medicinal compounds such as curcumin from turmeric, and polymeric substances like gums.
Thus, lectins, curcumin, and gums, as mentioned in the options, are all secondary metabolites, making option D. All of these the correct answer.
DDT residues are rapidly passed through food chain causing biomagnifications because DDT is
A) liposoluble
B) moderately toxic
C) non-toxic to aquatic animals
D) water soluble
The correct answer is A) liposoluble.
Many pesticides and insecticides, including DDT, aldrin, and dieldrin, tend to accumulate in the environment due to their properties. These substances are fat-soluble and non-biodegradable, leading to their incorporation into food chains. As they pass through various trophic levels, they tend to deposit in the fatty tissues of animals and humans. This accumulation and increase in concentration at each trophic level is known as biological magnification or biomagnification.
Match the biological molecules listed under column I with their biological functions listed under column II. Choose the answer which gives the correct combinations from the two columns.
Column I (Biological Molecule) | Column II (Function) |
---|---|
A. Glycogen | 1. Hormone |
B. Globulin | 2. Biocatalyst |
C. Steroid | 3. Antibody |
D. Thrombin | 4. Storage product |
A $\quad \begin{array}{llll}A & B & C & D \ 3 & 2 & 4 & 1\end{array}$
B $\quad \begin{array}{llll}A & B & C & D \ 4 & 2 & 1 & 3\end{array}$
C $\quad \begin{array}{llll}A & B & C & D \ 2 & 4 & 3 & 1\end{array}$
D $\quad \begin{array}{llll}A & B & C & D \ 4 & 3 & 1 & 2\end{array}$
The correct option is D. Here’s the correct matching from Column I (Biological Molecules) to Column II (Functions):
Glycogen matches '4. Storage product' as it is the main form of stored glucose in our body, particularly in the liver and muscle cells.
Globulin corresponds to '3. Antibody' because types of globulins function as antibodies, which are crucial components of the immune system.
Steroid is paired with '1. Hormone' because steroids include vital hormones like estrogen and cortisol, which are derived from cholesterol.
Thrombin is linked to '2. Biocatalyst' as it plays a critical enzymatic role by converting fibrinogen to fibrin in the blood clotting process.
This correct matching of molecules with their functions makes Option D the right answer.
Is an end product of anaerobic respiration:
A) Pyruvate
B) Lactic acid
C) Glucose
The correct answer is B) Lactic acid.
In anaerobic respiration, the end products can vary depending on the organism involved. Specifically, lactic acid is produced as an end product during anaerobic respiration in muscle cells under low oxygen conditions. This differs in yeast and plant cells, where the end products are carbon dioxide and ethanol. Thus, for the given options, lactic acid is an accurate example of an end product of anaerobic respiration.
Prostaglandins are:
A. Amino acids
B. Steroids
C. Fatty acids
D. Carbohydrates
The correct answer is C: Fatty acids.
Prostaglandins are types of lipid compounds that function similarly to hormones. They play a crucial role in the female reproductive system, helping to regulate processes such as ovulation, menstruation, and childbirth.
Phosphorus is an important component of:
A) DNA B) ATP C) Only Proteins D) Lipids
Phosphorus is a vital element in various biological molecules and plays a crucial role in different aspects of cellular function. The correct options are:
A) DNA
B) ATP
D) Lipids
Detailed Explanation:
DNA and RNA: Phosphorus is integral to the molecular structure of DNA and RNA, which are essential for genetic information processing in every living organism.
ATP: Also known as adenosine triphosphate, ATP serves as the primary energy carrier in cells. Phosphorus forms part of this molecule, crucial for storing and transporting cellular energy.
Lipids: Specifically, phosphorus is found in phospholipids that make up the cell membrane, playing a key role in cell structure and function.
Hence, phosphorus is not found only in proteins (as option C suggests), but is widely distributed in these other critical cellular components.
In a protein molecule, various amino acids are linked together by:
A. a peptide bond
B. a dative bond
C. a glycosidic bond
D. a B glycosidic bond
The correct answer is A. peptide bond.
Proteins are linear polymers formed by linking the $\alpha$-carboxyl group of one amino acid to the $\alpha$-amino group of another amino acid through a peptide bond (also referred to as an amide bond). This type of bond is essential for the structure and function of proteins.
Write down the biochemical process which is blocked by sulfa drugs in bacteria.
Sulfa drugs specifically block the biosynthesis of folic acid in bacteria. Folic acid is crucial for bacterial growth and reproduction, and by inhibiting this pathway, sulfa drugs effectively impede bacterial proliferation.
"Amino acid which takes part in the formation of thyroxine is:
A) Thyroglobulin
B) Lysine
C) Iodine
D) Tyrosine"
The correct answer is D) Tyrosine.
Thyroxine, also known as tetraiodothyronine (T4), is a hormone produced by the thyroid gland, which is situated in the neck. The gland itself contains follicular cells that synthesize both T4 and triiodothyronine (T3). To produce these hormones, the follicular cells incorporate the amino acid tyrosine into a glycoprotein called thyroglobulin. This combination is then secreted into the lumen of the follicle.
Thyroglobulin serves as the precursor from which thyroid hormones are synthesized. The tyrosine residues within thyroglobulin undergo iodination; that is, iodine ions attach to these residues. Depending on how many iodine ions associate with the tyrosine residues, the resulting molecules are either monoiodotyrosine or diiodotyrosine. These iodinated forms of tyrosine then conjugate to form either T3 or T4. Therefore, the amino acid directly involved in the formation of thyroxine is tyrosine (Option D).
Glucose drinks provide instant energy.
A) True
B) False
The correct answer is A) True.
Glucose is a simple sugar that the body uses as a source of instant energy. Ordinarily, the digestion process, where food is broken down starting from the mouth and absorbed into the body as glucose, can take up to 4 hours. However, glucose in liquid form, such as in glucose drinks, bypasses much of this extensive digestive process. Therefore, when a person who is extremely tired or in need of an immediate energy boost consumes a glucose drink, the body can quickly absorb the glucose directly into the bloodstream. This is why glucose drinks are effective for delivering rapid energy.
The rise in the boiling point of a solution containing 1.8 grams of glucose in 100 g of a solvent is 0.1°C. The molal elevation constant of the liquid is
A) 0.01 K/m
B) 0.1 K/m
C) 1 K/m
D) 10 K/m
To determine the molal elevation constant (Kb), we can use the formula for boiling point elevation:
$$ \Delta T_b = K_b \cdot m $$
Where:
$\Delta T_b$ is the change in boiling point
$K_b$ is the molal elevation constant
$m$ is the molality of the solution
Given:
$\Delta T_b = 0.1^\circ C$
Mass of glucose ($C_6H_{12}O_6$) = 1.8 g
Mass of solvent = 100 g
First, calculate the molar mass of glucose. Glucose has a molecular formula of $C_6H_{12}O_6$, and its molar mass is calculated as follows:
$$ M_{glucose} = (6 \times 12) + (12 \times 1) + (6 \times 16) = 72 + 12 + 96 = 180 \text{ g/mol} $$
Next, to find the molality ($m$):
$$ m = \frac{\text{Moles of solute}}{\text{Kilograms of solvent}} $$ $$ m = \frac{\frac{1.8 \text{ g}}{180 \text{ g/mol}}}{0.1 \text{ kg}} = \frac{0.01 \text{ moles}}{0.1 \text{ kg}} = 0.1 \text{ mol/kg} $$
Now, using the boiling point elevation formula, solve for $K_b$:
$$ 0.1^\circ C = K_b \cdot 0.1 , \text{mol/kg} $$ $$ K_b = \frac{0.1^\circ C}{0.1 , \text{mol/kg}} = 1 , K/m $$
Therefore, the molal elevation constant of the liquid is 1 K/m. The correct answer is:
C) 1 K/m
Which of the following is a simple sugar or monosaccharide?
A. Galactose
B. Lactose
C. Maltose
D. Sucrose
The correct answer is A. Galactose.
Galactose is a type of monosaccharide, which are the simplest form of carbohydrates. Unlike lactose, maltose, and sucrose which are disaccharides, comprising two linked sugar molecules, galactose consists of only a single sugar molecule, making it a monosaccharide. Examples of other monosaccharides include glucose and fructose. Monosaccharides serve as building blocks for more complex carbohydrates.
"Damage to structure and biological activity of the product is not desirable during downstream processing."
A) True
B) False
The correct answer is A) True.
The primary objective of downstream processing is to extract and purify products in a manner that preserves their structural integrity and biological activity. Thus, any damage to these properties during processing is indeed undesirable.
Which of the following is not a function of Golgi apparatus?
A) Protein synthesis
B) Formation of lysosome
C) Modification of proteins
D) Packaging of proteins
The correct answer is A) Protein synthesis.
The Golgi apparatus is primarily involved in the modification, sorting, and packaging of proteins for secretion. It also plays a critical role in the formation of lysosomes. Protein synthesis, however, does not occur in the Golgi apparatus; it is primarily carried out by ribosomes in the cell, typically those attached to the endoplasmic reticulum (ER).
Molecular mass of glycine is $75 \mathrm{~g/mol}$, methionine is $149 \mathrm{~g/mol}$, alanine is $89 \mathrm{~g/mol}$, valine is $117 \mathrm{~g/mol}$, and phenylalanine is $165 \mathrm{~g/mol}$.
Then, what would be the molecular mass of a protein with the sequence Gly - Ala - Phe - Val - Met - Gly?
A) $595 \mathrm{~g/mol}$ B) $523 \mathrm{~g/mol}$ C) $670 \mathrm{~g/mol}$ D) $580 \mathrm{~g/mol}$
The correct answer is D) $580 , \mathrm{g/mol}$.
The given protein sequence is Gly - Ala - Phe - Val - Met - Gly. To calculate the molecular mass of this protein, remember that each peptide bond formation results in the loss of a water molecule, which has a molecular mass of $18 , \mathrm{g/mol}$. With 5 peptide bonds in this sequence, the mass adjustment involves subtracting the mass of 5 water molecules:
Calculate the total molecular mass of the amino acids in the sequence: $$ (2 \times \text{Molecular mass of Gly}) + (\text{Molecular mass of Ala}) + (\text{Molecular mass of Phe}) + (\text{Molecular mass of Val}) + (\text{Molecular mass of Met}) $$ $$ = (2 \times 75) + 89 + 165 + 117 + 149 $$ $$ = 670 , \mathrm{g/mol} $$
Subtract the mass of the water molecules released during peptide bond formation: $$ \text{Total mass} - (5 \times \text{Mass of one water molecule}) $$ $$ = 670 - (5 \times 18) $$ $$ = 670 - 90 $$ $$ = 580 , \mathrm{g/mol} $$
Thus, the molecular mass of the protein is 580 g/mol.
Conversion of ATP to ADP releases:
A. Enzymes
B. Secretions
C. Energy
D. Hormones
The question is asking about the conversion of ATP to ADP. ATP (Adenosine Triphosphate) is a high-energy molecule that stores and supplies energy necessary for various cellular activities in the body. During cellular respiration, ATP is produced through various metabolic processes. The conversion of ATP to ADP (Adenosine Diphosphate) releases one of its phosphate groups, resulting in the generation of energy.
The correct answer is:
C. Energy
Which of the following acid is also a vitamin:
A. Ascorbic acid
B. Formic acid
C. Malic acid
D. Palmitic acid
The correct answer to which of the following acids is also a vitamin is:
A. Ascorbic acid
Ascorbic acid is commonly known as Vitamin C. It plays a crucial role in the body's immune system by providing protection against various pathogens and agents. Vitamin C is also essential for maintaining healthy skin, blood vessels, bones, and cartilage, as well as aiding in the healing process.
Sources of Vitamin C are predominantly citrus fruits. Among these, fruits like oranges, lemons, and notably, apples, contain a high amount of Ascorbic acid. The importance of Vitamin C in the diet is highlighted by its numerous functions, which are crucial to maintaining good health and immune defense.
Other options in the question:
B. Formic acid
C. Malic acid
D. Palmitic acid
None of these are vitamins. Formic acid is commonly associated with the sting of ants, Malic acid is known for its role in the tart taste of fruits, and Palmitic acid is a type of fatty acid found in palm oil and meats.
Find the wrong pair.
Option 1) Cellulose – Heteropolymer
Option 2) Protein – Insulin
Option 3) Secondary metabolite – anthocyanin
Option 4) Primary metabolite – Ribose
The correct option is $\mathbf{A}$.
Cellulose is not a heteropolymer.
Cellulose constitutes the primary structural component of plant cell walls. It is a linear homopolymer made up of $\beta$-D-glucose units linked via $\beta$-1,4 glycosidic bonds. These linear chains organize into microfibrils or bundles, which are held together by hydrogen bonds.
💡 Have more questions?
Ask Chatterbot AINCERT Solutions - Biomolecules | NCERT | Biology | Class 11
What are macromolecules? Give examples.
Macromolecules are large, complex molecules typically found in the acid-insoluble fraction of living tissues. They usually have molecular weights in the range of ten thousand daltons and above. The primary examples include:
- Proteins: Polymers of amino acids. Examples: Collagen, enzymes like trypsin, and hormones like insulin.
- Nucleic Acids: Polymers of nucleotides. Examples: DNA and RNA.
- Polysaccharides: Polymers of sugars. Examples: Cellulose, starch, and glycogen.
Lipids are also often included in macromolecular fractions due to their association with cell membranes, even though their molecular weights are typically smaller.
What is meant by tertiary structure of proteins?
The tertiary structure of proteins refers to the *three-dimensional folding* of the protein molecule. This involves the overall shape resulting from bends and folds of the protein chain. Specifically, it is the complex three-dimensional arrangement of all the atoms in the protein, including how the *alpha-helices, beta-sheets, and other elements are folded on themselves*. This structure is crucial for the biological activity of the protein, as it determines the specific *functional sites* such as the active site of enzymes.
Find and write down structures of 10 interesting small molecular weight biomolecules. Find if there is any industry which manufactures the compounds by isolation. Find out who are the buyers.
10 Interesting Small Molecular Weight Biomolecules
-
Glycine (Amino Acid)
- Structure:
- Manufactured by: Ajinomoto Co., Inc.
- Buyers: Pharmaceutical companies, food industry for use as a dietary supplement.
-
Alanine (Amino Acid)
- Structure:
- Manufactured by: Evonik Industries AG
- Buyers: Biomedical research companies, nutritional supplement producers.
-
Serine (Amino Acid)
- Structure:
- Manufactured by: Kyowa Hakko Bio Co., Ltd.
- Buyers: Cosmetic companies, pharmaceutical industries.
-
Glucose (Monosaccharide)
- Structure:
- Manufactured by: Cargill, Incorporated
- Buyers: Food and beverage industry, medical supply companies.
-
Ribose (Pentose Sugar)
- Structure:
- Manufactured by: Bioenergy Life Science, Inc.
- Buyers: Sports nutrition companies, pharmaceutical industry.
-
Palmitic Acid (Fatty Acid)
- Structure:
- Manufactured by: Wilmar International Ltd.
- Buyers: Soap manufacturers, cosmetic companies, food industries.
-
Adenine (Nitrogenous Base)
- Structure:
- Manufactured by: Merck & Co., Inc.
- Buyers: DNA research labs, pharmaceutical industries.
-
Uracil (Nitrogenous Base)
- Structure:
- Manufactured by: Thermo Fisher Scientific Inc.
- Buyers: Biotechnology companies, genetic research labs.
-
Glycerol (Alcohol)
- Structure:
- Manufactured by: P&G Chemicals
- Buyers: Cosmetic and skincare product manufacturers, food processing industry.
-
Lactic Acid (Alpha-hydroxy Acid)
- Structure: Lactic Acid Structure
- Manufactured by: Corbion N.V.
- Buyers: Bioplastic manufacturers, food industry, cosmetic products manufacturers.
Industries and Buyers
These biomolecules are commonly used in various industries for different purposes. Here are the main sectors and typical buyers:
- Pharmaceutical Industry: Buys amino acids like glycine and alanine for synthesis of drugs and dietary supplements.
- Food and Beverage Industry: Glucose and ribose are significant in energy drinks, sports nutrition products, and as sweeteners.
- Cosmetic Industry: Serine, palmitic acid, and glycerol are used in skin care and beauty products.
- Biomedical Research: Adenine and uracil are essential for nucleic acid research and genetic studies.
- Biotechnology Companies: Commonly purchase various amino acids and nitrogenous bases for research and development.
- Chemical Manufacturing: Lactic acid is used in the production of bioplastics and eco-friendly packaging.
Find out and make a list of proteins used as therapeutic agents. Find other applications of proteins (e.g., Cosmetics etc.)
Sure, let's address the query based on the chapter provided.
-
Proteins Used as Therapeutic Agents:
- Insulin: Used to treat diabetes by regulating blood sugar levels.
- Human Growth Hormone (HGH): Used to treat growth disorders in children and growth hormone deficiency in adults.
- Interferons: Used in the treatment of viral infections and cancer.
- Erythropoietin: Used to treat anemia, particularly in chronic kidney disease.
- Monoclonal Antibodies: Used in the treatment of various cancers and autoimmune diseases.
-
Other Applications of Proteins:
-
Cosmetics:
- Collagen: Used in anti-aging creams and treatments to improve skin elasticity.
- Elastin: Incorporated in skin care products to enhance skin flexibility.
-
Food Industry:
- Casein and Whey: Used as dietary supplements to improve protein intake.
- Gluten: Used in baking to provide elasticity to dough.
-
Industrial Applications:
- Proteases: Used in laundry detergents to break down protein stains.
- Amylases and Lipases: Also used in detergents and various industrial processes.
-
Research and Biotechnology:
- Restriction Enzymes: Used in genetic engineering to cut DNA at specific sequences.
- DNA Polymerases: Used in polymerase chain reactions (PCR) to amplify DNA.
-
Cosmetics:
These proteins play crucial roles not only in therapeutic settings but also across various industries, highlighting their diverse applications.
Explain the composition of triglyceride.
Triglycerides are a type of lipid composed of three fatty acid chains esterified to a single glycerol molecule. Here is a more detailed breakdown:
- Glycerol: This is a three-carbon alcohol which acts as the backbone to which fatty acids are attached.
-
Fatty Acids: Each glycerol molecule is esterified with three fatty acids. The fatty acids can vary in length and degree of saturation:
- Saturated Fatty Acids: These have no double bonds between carbon atoms.
- Unsaturated Fatty Acids: These have one or more double bonds in the carbon chain.
Triglycerides can be classified as:
- Monoglycerides: Glycerol + 1 fatty acid
- Diglycerides: Glycerol + 2 fatty acids
- Triglycerides: Glycerol + 3 fatty acids
When glycerol and fatty acids combine, they form an ester bond through a dehydration synthesis reaction. Triglycerides are commonly found as oils and fats, with oils usually being liquid at room temperature and fats being solid.
Important points:
- Esterification: The process by which fatty acids are attached to glycerol, forming ester bonds.
- Saturation: Determines whether the triglyceride will be liquid or solid at room temperature.
Here's a simplified diagram showing a triglyceride composition:
Glycerol + 3 Fatty Acids --> Triglyceride
Thus, triglycerides are a crucial form of energy storage in living organisms, owing to their dense energy content.
Can you attempt building models of biomolecules using commercially available atomic models (Ball and Stick models).
Yes, you can build models of biomolecules using commercially available atomic models, such as Ball and Stick models. These models can help you visually understand the structure and arrangement of atoms in biomolecules. For instance:
-
Amino Acids: You can represent the central $\alpha$-carbon, amino group ($-\mathrm{NH}_2$), carboxyl group ($-\mathrm{COOH}$), hydrogen atom, and variable R group. Example amino acids like glycine, alanine, and serine can be modeled this way.
-
Fatty Acids: These can be constructed to show the long hydrocarbon chains ending in a carboxyl group ($-\mathrm{COOH}$). For example, palmitic acid and arachidonic acid.
-
Carbohydrates: You can model simpler sugars like glucose ($\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$) or ribose ($\mathrm{C}_5\mathrm{H}_{10}\mathrm{O}_5$).
-
Nucleotides/Nucleic Acids: Model the nitrogenous bases (adenine, guanine, thymine, cytosine, and uracil), the pentose sugar (ribose or deoxyribose), and the phosphate group.
-
Proteins: Represent polypeptides by connecting amino acid residues using peptide bonds.
Macromolecules may also involve complex assembly, like DNA double helices where base-pairing (A-T, G-C) can be illustrated.
These models are highly beneficial for educational purposes, helping students to visualize molecular geometry, bond angles, and the spatial relationships between different atoms.
Draw the structure of the amino acid, alanine.
The structure of the amino acid alanine is as follows:
Alanine: H(_2)N-CH(CH(_3))-COOH
Here is the diagrammatic representation:
H
|
H2N-C-COOH
|
CH3
In this structure:
- The central carbon (C) is the α-carbon.
- The amino group (H(_2)N) is attached to the α-carbon.
- The carboxyl group (COOH) is also attached to the α-carbon.
- The R group is a methyl group (CH(_3)) in the case of alanine.
- Additionally, a hydrogen atom (H) is also attached to the α-carbon.
What are gums made of? Is Fevicol different?
Gums are secondary metabolites that can be found in plant tissues. They are classified as polymeric substances composed of complex polysaccharides, chemically modified sugars (e.g., glucosamine, N-acetyl galactosamine), and sometimes amino-sugars.
Fevicol is different; it is a synthetic adhesive primarily composed of polyvinyl acetate (PVA) emulsion. Fevicol and gums share the adhesive function, but their chemical compositions are distinctly different.
Key differences:
- Gums: Derived from natural sources, complex polysaccharides.
- Fevicol: Synthetic, primarily composed of polyvinyl acetate.
Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them.
To perform qualitative tests for proteins, fats and oils, and amino acids on samples like fruit juice, saliva, sweat, and urine, you can use the following methods:
Proteins (Biuret Test)
- Procedure: Add a few drops of Biuret reagent (a solution of sodium hydroxide and copper sulfate) to the sample.
- Observation: A color change to violet or purple indicates the presence of proteins.
Fats and Oils (Sudan III Test)
- Procedure: Add a few drops of Sudan III stain solution to the sample.
- Observation: The appearance of red-stained oil droplets indicates the presence of fats and oils.
Amino Acids (Ninhydrin Test)
- Procedure: Add a few drops of ninhydrin solution to the sample and heat it gently.
- Observation: A blue or purple coloration indicates the presence of amino acids.
Testing the Samples
-
Fruit Juice
- Proteins: Add Biuret reagent and observe.
- Fats and Oils: Add Sudan III stain and observe.
- Amino Acids: Add ninhydrin solution and heat, then observe.
-
Saliva
- Proteins: Add Biuret reagent and observe.
- Fats and Oils: Add Sudan III stain and observe.
- Amino Acids: Add ninhydrin solution and heat, then observe.
-
Sweat
- Proteins: Add Biuret reagent and observe.
- Fats and Oils: Add Sudan III stain and observe.
- Amino Acids: Add ninhydrin solution and heat, then observe.
-
Urine
- Proteins: Add Biuret reagent and observe.
- Fats and Oils: Add Sudan III stain and observe.
- Amino Acids: Add ninhydrin solution and heat, then observe.
Note
- Ensure to wear appropriate lab safety gear such as gloves and goggles.
- Dispose of the chemicals and biological samples properly according to your local regulations.
Conclusion
By using the Biuret test for proteins, Sudan III test for fats and oils, and Ninhydrin test for amino acids, you can qualitatively determine the presence of these biomolecules in various samples including fruit juice, saliva, sweat, and urine.
Find out how much cellulose is made by all the plants in the biosphere and compare it with how much of paper is manufactured by man and hence what is the consumption of plant material by man annually. What a loss of vegetation!
Based on the WolframAlpha query, the annual paper production worldwide is approximately 365.1 million metric tons (as of 2006 estimates).
However, accurate data for the annual cellulose production by all plants in the world was not available from WolframAlpha. Due to the complexity of measuring and aggregating global cellulose production by plants, this data might not be readily obtainable from that source.
To ensure an accurate comparison and understanding of plant material consumption for paper production, one might need to refer to comprehensive scientific studies or databases dedicated specifically to botanic and industrial biomass statistics.
Nonetheless, even from the given data:
- 365.1 million metric tons of paper are produced annually.
Given that cellulose is a primary component of plant biomass used in paper production, this figure indicates a significant annual consumption of plant-derived cellulose for paper manufacturing alone.
Highlighting the key points:
- Paper Production Annually: 365.1 million metric tons.
This large quantity underscores the immense impact on vegetation and plant material consumption by humans each year, reflecting the substantial environmental challenge we face due to deforestation and biomass utilization for industrial purposes.
Describe the important properties of enzymes.
Certainly! Here are the important properties of enzymes:
- Nature: Almost all enzymes are proteins, though some nucleic acids (ribozymes) can also act as enzymes.
- Active Site: Enzymes contain a specific region called the active site, which binds the substrate.
- Catalytic Power: Enzymes catalyze reactions at a very high rate. They greatly accelerate the reaction rates compared to the corresponding uncatalyzed reactions.
- Specificity: Enzymes exhibit high substrate specificity. They will only act on specific substrates to catalyze a particular type of reaction.
- Optimum Conditions: Enzyme activity is affected by environmental conditions like temperature and pH. Each enzyme has an optimum temperature and optimum pH at which it is most active.
- Thermal Stability: Enzymes from thermophilic organisms are stable and retain their catalytic power at high temperatures (up to (80^\circ - 90^\circ C)).
- Reaction: Enzymes can be inhibited by chemicals resembling the substrate, leading to a process called competitive inhibition.
- Activation Energy: Enzymes lower the activation energy required for reactions, making it easier for the substrate to be converted into the product.
- Reaction Pathway: They bring about the formation of a transient enzyme-substrate (ES) complex. This complex transforms the substrate into a product.
These properties enable enzymes to efficiently catalyze biochemical reactions under the mild conditions that prevail in biological systems.
💡 Have more questions?
Ask Chatterbot AINotes - Biomolecules | Class 11 NCERT | Biology
Ultimate Guide to Biomolecules: Class 11 Notes
Biomolecules are fundamental to life on Earth. For Class 11 students, understanding biomolecules is crucial for mastering the basics of biology and chemistry. This guide aims to provide detailed notes on the various aspects of biomolecules, focusing on their classification, functions, and significance in living organisms.
Introduction to Biomolecules
Biomolecules are the chemical compounds found in living organisms. They play an essential role in maintaining the structure and functions of cells, tissues, and organs. These molecules include proteins, nucleic acids, polysaccharides, lipids, and various metabolites.
Analyzing Chemical Composition
How to Analyse Chemical Composition?
To analyse the chemical composition of biomolecules, scientists perform various experiments using living tissues. A typical method involves grinding the sample in trichloroacetic acid, obtaining an acid-soluble fraction (filtrate) and an acid-insoluble fraction (retentate). The acid-soluble fraction contains a myriad of organic compounds, while the acid-insoluble fraction contains significant biomacromolecules.
Metabolites in Living Organisms
Primary and Secondary Metabolites
Primary metabolites include essential compounds like amino acids, sugars, and nucleotides found in animal tissues. Secondary metabolites, often found in plants and microbes, include alkaloids, flavonoids, and pigments. These secondary metabolites may not have direct roles in normal physiological processes but are valuable for human welfare, like medicines.
Biomacromolecules
Definition of Biomacromolecules
Biomacromolecules are large molecules found in the acid-insoluble fraction of living tissues. These include proteins, nucleic acids, and polysaccharides, generally having molecular weights above 10,000 Daltons.
Characteristics and Functions
Biomacromolecules are essential for the structural and functional integrity of cells. They serve as enzymes, genetic material, energy reserves, and structural components.
Proteins
Structure and Composition
Proteins are heteropolymers composed of amino acids linked by peptide bonds. They exhibit four levels of structure:
- Primary structure: Amino acid sequence
- Secondary structure: Alpha helices and beta sheets
- Tertiary structure: Three-dimensional folding
- Quaternary structure: Multiple polypeptide subunits
Functions of Proteins
Proteins have diverse functions, including enzyme catalysis, nutrient transport, hormone activity, immune defence, and structural support. Examples include collagen (structural protein) and RuBisCO (enzyme in photosynthesis).
Polysaccharides
Characteristics and Types
Polysaccharides are long chains of sugar molecules. Common types include:
- Cellulose: Structural component in plants
- Starch: Energy storage in plants
- Glycogen: Energy storage in animals
Nucleic Acids
RNA and DNA
Nucleic acids are polynucleotides that store and transmit genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) differ in their sugar molecules and types of nitrogen bases.
Enzymes
Nature and Function
Enzymes are proteins that catalyse biochemical reactions. They lower the activation energy, thereby increasing the reaction rate. Enzymes are highly specific to their substrates and operate within optimal temperature and pH ranges.
Factors Affecting Enzyme Activity
Several factors influence enzyme activity, including temperature, pH, and substrate concentration. Enzyme inhibitors can also modulate enzyme activity, either competitively or non-competitively.
graph TD
A[Substrate] -->|binds to| B[Enzyme]
B --> C[Enzyme-Substrate Complex]
C -->|releases| D[Product]
C -->|releases| B[Enzyme]
Enzyme Inhibition
Enzyme inhibitors can be competitive (resemble the substrate) or non-competitive (bind to a different site). Inhibitors are often used to control bacterial pathogens.
Chemical Reactions and Enzyme Activity
Chemical Changes in Reactions
Chemical reactions involve the breaking and forming of bonds, transforming substrates into products. Enzymes facilitate these reactions by stabilising the transition state.
graph LR
A[Substrate] --> B[Transition State] --> C[Product]
E[Enzyme] circle>-.-|Lowers Activation Energy| B
Understanding Enzyme Catalysis
Enzyme catalysis involves the formation of an enzyme-substrate complex, leading to the transition state and finally the product. This process repeats in a catalytic cycle.
Co-factors in Enzymatic Activity
Types of Co-factors
Co-factors are non-protein molecules that aid enzyme activity. They can be:
- Prosthetic groups: Tightly bound to the enzyme
- Co-enzymes: Transiently associated organic molecules
- Metal ions: Essential for enzyme activity
Summary
Biomolecules, despite their diverse roles, share significant similarities in their chemical composition. Proteins, nucleic acids, and polysaccharides are the primary macromolecules, each with unique functions. Enzymes, mainly proteinaceous, catalyse biochemical reactions, ensuring the sustenance of life. Understanding these biomolecules offers insights into the intricate workings of living organisms, a critical aspect of biology and chemistry for Class 11 students.
🚀 Learn more about Notes with Chatterbot AI