Mix Examples- Biomolecules Questions in English

(B) The correct match is Vitamin $E$ - tocopherol.
Vitamin $A$ is retinol.
Vitamin $D$ is calciferol.
Vitamin $K$ is phylloquinone.
Vitamin $E$ is known as tocopherol and is often referred to as the anti-sterility vitamin.

(B) In the body of vertebrates,energy reserves are primarily stored as $Fat$ and $Glycogen$.
$Glycogen$ is stored in the liver and muscles for quick energy release,while $Fat$ (in the form of adipose tissue) serves as a long-term,high-energy storage molecule.

(B) Vitamin $E$ (tocopherol) is known as the antisterility vitamin because its deficiency leads to reproductive failure and sterility in many animals.
Vitamin $D$ is often associated with calcium metabolism (decalcifying/calcifying).
Vitamin $K$ is known as the antihaemophilic or prothrombin vitamin as it is essential for the synthesis of clotting factors.

(A) Antioxidants are substances that help protect cells from damage caused by free radicals.
Among the vitamins,Vitamin $C$ (ascorbic acid),Vitamin $E$ (tocopherol),and Vitamin $A$ (retinol/beta-carotene) are well-known for their potent antioxidant properties.
These vitamins neutralize free radicals,thereby reducing oxidative stress in the body.
Therefore,the correct group of antioxidant vitamins is Vitamin $C, E, A$.

(D) Fat-soluble vitamins are those that dissolve in fats and oils. These include vitamins $A, D, E,$ and $K$.
Among the given options,Tocopherol is Vitamin $E$,which is fat-soluble.
Thiamine (Vitamin $B_1$),Folic acid (Vitamin $B_9$),and Ascorbic acid (Vitamin $C$) are water-soluble vitamins.

(B) $ATP$ (Adenosine Triphosphate) was first isolated from muscle tissue by the German biochemist $K. Lohmann$ in $1929$. It is known as the energy currency of the cell.

(B) $ATP$ (Adenosine Triphosphate) is known as the energy currency of the cell.
It acts as the primary and immediate source of energy for various metabolic processes,muscle contraction,and active transport within living organisms.
When $ATP$ is hydrolyzed into $ADP$ and inorganic phosphate,a significant amount of energy is released,which is utilized by the cell to perform work.

(C) An antioxidant is a molecule that inhibits the oxidation of other molecules.
Oxidation is a chemical reaction that can produce free radicals,leading to chain reactions that may damage cells.
Antioxidants terminate these chain reactions by removing free radical intermediates and inhibit other oxidation reactions by being oxidized themselves.
Therefore,the correct answer is $C$ (Antioxidant).

(A) Pyrophosphate cleavage refers to the hydrolysis of a pyrophosphate bond ($P-O-P$ bond) within a molecule.
When $ATP$ (Adenosine Triphosphate) is converted into $AMP$ (Adenosine Monophosphate),the enzyme releases inorganic pyrophosphate $(PPi)$ by breaking the bond between the alpha and beta phosphate groups.
This process involves the cleavage of two high-energy phosphate bonds simultaneously,which is characteristic of pyrophosphate cleavage.
Therefore,the correct option is $A$.

(A) In haemoglobin,the iron atom is present in the ferrous $(Fe^{2+})$ state.
This ferrous iron is essential for the reversible binding of oxygen to form oxyhaemoglobin.
If the iron is oxidized to the ferric $(Fe^{3+})$ state,the haemoglobin becomes methaemoglobin,which is unable to bind oxygen effectively.

(D) Disorders of amino acid metabolism are genetic conditions caused by the deficiency of specific enzymes required for the breakdown of amino acids.
$1$. $Alkaptonuria$ is caused by a deficiency of the enzyme homogentisate $1,2$-dioxygenase, leading to the accumulation of homogentisic acid.
$2$. $Phenylketonuria$ $(PKU)$ is caused by a deficiency of the enzyme phenylalanine hydroxylase, which prevents the conversion of phenylalanine to tyrosine.
$3$. $Albinism$ is often caused by a defect in the enzyme tyrosinase, which is required for the synthesis of melanin from tyrosine.
Since all three conditions are metabolic disorders related to amino acid pathways, the correct answer is $All \text{ of the above}$.

(D) Temperature is defined as a measure of the average kinetic energy of the particles in a substance.
Since kinetic energy is directly related to the velocity of particles $(KE = \frac{1}{2}mv^2)$,temperature serves as a measure of the average velocity of molecular movement.
As the temperature increases,the average velocity of the molecules increases.

(A) polar covalent bond is formed when electrons are shared unequally between two atoms.
This occurs because one atom has a higher electronegativity than the other, causing it to attract the shared electron pair more strongly towards its nucleus.
As a result, the atom with higher electronegativity acquires a partial negative charge $(\delta^-)$, while the other atom acquires a partial positive charge $(\delta^+)$.

(D) The correct answer is $D$.
Most of the unique and important properties of water,such as high specific heat,cohesion,and surface tension,are due to the presence of hydrogen bonds.
These are weak electrostatic attractions formed between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another water molecule.

(A) Proteins act as emulsifying agents. When a protein is added to an oil-in-water emulsion and shaken,the protein molecules adsorb at the interface between the oil droplets and the water. This forms a protective film around the oil droplets,which prevents them from coalescing and thereby stabilizes the emulsion.

(B) The correct matching is as follows:
$1$. $(A)$ $ATP$ (Adenosine Triphosphate) is the primary energy currency of the cell,acting as the main source of energy: $(q)$.
$2$. $(B)$ $DNA$ (Deoxyribonucleic Acid) consists of two polynucleotide strands coiled around a common axis: $(r)$.
$3$. $(C)$ Protein is a polymer formed by a long sequence of amino acids linked by peptide bonds: $(s)$.
$4$. $(D)$ Carbohydrate is a biomolecule composed of one or more sugar monomers (monosaccharides): $(p)$.
Therefore,the correct combination is $A-q, B-r, C-s, D-p$.

(A) The correct matches are as follows:
$1$. $(A)$ Ketone: $A$ ketone contains a carbonyl group $(C=O)$ located within the carbon chain. Thus,$(A)$ matches with $(s)$.
$2$. $(B)$ Fatty acid: $A$ fatty acid consists of a long hydrocarbon chain with a carboxyl group $(-COOH)$ at one end. Thus,$(B)$ matches with $(q)$.
$3$. $(C)$ Aldehyde: An aldehyde contains a carbonyl group $(C=O)$ at the terminal end of the carbon chain. Thus,$(C)$ matches with $(r)$.
$4$. $(D)$ Nucleotide: $A$ nucleotide is the basic building block of nucleic acids,consisting of a $5$-carbon sugar (pentose),a phosphate group,and a nitrogenous base. Thus,$(D)$ matches with $(p)$.
Therefore,the correct combination is $A = s, B = q, C = r, D = p$.

(A) In an $ATP$ (Adenosine Triphosphate) molecule,the adenosine moiety consists of an adenine base attached to a ribose sugar.
When the first phosphate group is attached to the $5'$-carbon of the ribose sugar,it forms a covalent bond known as a phosphoester bond.
The subsequent two phosphate groups are attached to each other via phosphoanhydride bonds.

(C) The chemical formula of urea is $NH_2CONH_2$.
To calculate the percentage of nitrogen,we first find the molar mass of urea:
$C = 12, H = 4, N = 28, O = 16$.
Total molar mass = $12 + 4 + 28 + 16 = 60 \text{ g/mol}$.
The mass of nitrogen in one mole of urea is $28 \text{ g}$.
Percentage of nitrogen = $(28 / 60) \times 100 \approx 46.66\%$.
Therefore,the nitrogen content is approximately $46\%$.

(B) Hydrogen bonds are crucial for life because they occur between water molecules,which gives water its unique properties like high specific heat,cohesion,and adhesion.
Additionally,hydrogen bonds are essential for maintaining the structure of biological macromolecules such as $DNA$ (holding base pairs together) and proteins (stabilizing secondary structures like alpha-helices and beta-pleated sheets).

(A) The $pH$ scale ranges from $0$ to $14$.
Solutions with a $pH$ less than $7$ are acidic.
As the $pH$ value increases towards $7$,the acidity of the solution decreases.
Therefore,among the given options $(1, 2.3, 4.5, 6)$,the value $6$ is closest to $7$,making it the least acidic solution.

(C) Water is a chemical compound with the formula $H_2O$.
$A$ molecule is the smallest unit of a chemical compound that retains the chemical properties of that substance.
Since water is a compound,its smallest particle that can exist independently while maintaining its chemical identity is a molecule of $H_2O$.

(D) The elements $C, H, O$ and $N$ are fundamental components of biological macromolecules.
Nucleic acids ($DNA$ and $RNA$) are composed of nitrogenous bases,pentose sugars,and phosphate groups,which contain $C, H, O, N$ and $P$.
Proteins are polymers of amino acids,which contain an amino group $(-NH_2)$,a carboxyl group $(-COOH)$,and a variable side chain $(R)$,thus containing $C, H, O$ and $N$.
Lipids primarily consist of $C, H$ and $O$,but generally lack nitrogen (except for phospholipids or specific complex lipids).
Therefore,both nucleic acids and proteins contain $C, H, O$ and $N$ in their structures.

(D) Amino acids are primarily synthesized from $\alpha$-ketoglutaric acid through the process of transamination.
In this process,the amino group is transferred from one amino acid to the keto group of $\alpha$-ketoglutaric acid,resulting in the formation of glutamic acid and other amino acids.

(D) Porphyrin is a heterocyclic macrocycle organic compound,composed of four modified pyrrole subunits interconnected at their alpha carbon atoms via methine bridges.
$1$. Chlorophyll contains a porphyrin ring with a central magnesium $(Mg^{2+})$ ion.
$2$. Hemoglobin contains a porphyrin ring (heme) with a central iron $(Fe^{2+})$ ion.
$3$. Cytochromes are iron-containing hemoproteins that also possess a porphyrin ring structure.
Therefore,all the given options contain porphyrin.

(D) In metabolic processes,the energy released during catabolic reactions is captured and stored in the form of $ATP$ (Adenosine Triphosphate).
$ATP$ is known as the energy currency of the cell.
When the cell requires energy for anabolic processes or other cellular activities,$ATP$ is hydrolyzed to $ADP$ and inorganic phosphate,releasing the stored energy.

(C) $ATP$ (Adenosine Triphosphate) is known as the energy currency of the cell.
It is the immediate and common source of energy for all cellular processes because it releases energy upon hydrolysis of its terminal phosphate bond.
While glucose is the primary respiratory substrate used to generate energy,it must first be converted into $ATP$ to be utilized by the cell for various metabolic activities.

(D) Biochemical processes in living organisms are complex and highly regulated.
$1$. Enzymes act as biological catalysts that speed up chemical reactions.
$2$. Hormones act as chemical messengers that regulate various physiological processes.
$3$. Vitamins function as co-factors or co-enzymes essential for metabolic reactions.
$4$. Nucleotides are the building blocks of nucleic acids ($DNA$ and $RNA$) and are involved in energy transfer $(ATP)$ and signaling,but they are not catalysts or regulators in the same sense as the others. However,in the context of standard biological questions regarding 'biochemical processes' components,all listed options are actually involved. If this is a multiple-choice question where one must be excluded,it is often a poorly framed question. Given the options,all are essential components. If forced to choose the most distinct,all are involved in metabolism. Assuming the question implies 'catalytic' or 'regulatory' roles,all are involved. Re-evaluating: All options $(A, B, C, D)$ are essential for biochemical processes. If this is a standard test question,there may be an error in the premise. However,if we consider 'Nucleotides' as structural units rather than functional regulators,they are the least likely to be termed 'biochemical agents' in some contexts.

(C) $ATP$ (Adenosine Triphosphate) is known as the energy currency of the cell.
It stores energy in its high-energy phosphate bonds.
When the cell requires energy for metabolic processes,$ATP$ is hydrolyzed to $ADP$ (Adenosine Diphosphate) and inorganic phosphate,releasing the stored energy.

(C) In living cells,the energy released during metabolic processes like respiration is not used directly for cellular work. Instead,it is trapped and stored in the form of Adenosine Triphosphate $(ATP)$ molecules. $ATP$ is known as the energy currency of the cell because it can be easily broken down to release energy whenever the cell requires it for various physiological activities.

(A) The hydrolysis of one molecule of $ATP$ into $ADP$ and inorganic phosphate $(Pi)$ releases energy.
Under standard physiological conditions, the free energy change $(\Delta G)$ for this reaction is approximately $-7.3$ kcal/mol.
Among the given options, $8$ kcal is the closest approximation to the energy released by the hydrolysis of one molecule of $ATP$.

(B) When fruits and vegetables are cut,the phenolic compounds (such as tannic acid) present in their cells are exposed to oxygen in the air. If a metal knife (containing iron) is used,the iron ions act as a catalyst. The oxidation of these phenolic compounds,often facilitated by the enzyme polyphenol oxidase and iron traces,leads to the formation of dark-colored pigments called melanins. This process is known as enzymatic browning.

(D) Water is essential for all living organisms.
$1$. It acts as a universal solvent,facilitating the transport of nutrients,gases,and waste products within the body.
$2$. It helps in thermoregulation by keeping the body cool through processes like sweating or panting.
$3$. It is also involved in various physiological processes,including those related to reproduction and cellular metabolism.
Therefore,all the given options are correct.

(B) Corn contains starch,which is a polysaccharide. When corn is boiled,the heat breaks down the cell walls and initiates the hydrolysis of starch. However,the key process involves the action of enzymes like amylase present in the corn. When the water cools down,these enzymes (which were not completely denatured or were reactivated) act on the starch to break it down into simpler sugars like maltose (a disaccharide) and glucose (a monosaccharide). The presence of these simple sugars makes the solution taste sweet. Therefore,the conversion of complex polysaccharides into simpler,sweet-tasting sugars is the reason for the sweetness.

(C) The body synthesizes fat when energy intake exceeds energy expenditure.
$1$. When blood glucose levels are high,the body first converts glucose into glycogen for storage in the liver and muscles.
$2$. Once the storage capacity for glycogen in the liver and muscles is reached (saturated),the excess glucose is converted into fatty acids and stored as adipose tissue (fat).
$3$. Therefore,when the storage of glycogen is full,the body shifts to lipogenesis to store excess energy as fat.

(B) $ATP$ (Adenosine Triphosphate) is known as the energy currency of the cell. It is the primary energy-rich molecule that stores and transfers energy for various metabolic processes in living organisms. While creatine phosphate,carbohydrates,and fats also store energy,$ATP$ is the immediate and direct source of energy used by cells.

(A) In the protoplasm of a cell, water exists in two primary forms: free water and bound water.
$1$. Free water constitutes about $95\%$ of the total water content in the cell and acts as a solvent for various metabolic reactions.
$2$. Bound water constitutes about $5\%$ of the total water content and is associated with macromolecules like proteins and carbohydrates.
Therefore, free water is found in the highest amount in the protoplasm.

(D) heterocyclic ring is a cyclic compound that has atoms of at least two different elements as members of its ring$(s)$.
$1$. Nitrogenous bases (purines and pyrimidines) contain heterocyclic rings where nitrogen atoms are part of the ring structure.
$2$. Monosaccharides,such as glucose or ribose,exist in a cyclic form in aqueous solutions,which also contains a heterocyclic ring (specifically,an oxygen atom is part of the ring,making it a heterocycle).
Therefore,both nitrogenous bases and the cyclic forms of monosaccharides contain heterocyclic rings.

(D) Statement $(a)$ is correct: Proteins are heteropolymers made of different amino acids.
Statement $(b)$ is correct: The pentose sugar in $DNA$ (deoxyribose) and $RNA$ (ribose) is in the $\beta$-furanose form.
Statement $(c)$ is correct: Nucleic acids are acidic due to the presence of phosphate groups in their backbone.
Statement $(d)$ is incorrect: $5$-methyl uracil (thymine) is attached to the first carbon of deoxyribose,not ribose.
Statement $(e)$ is incorrect: Collagen is the most abundant protein in the animal kingdom,not the plant kingdom (Rubisco is the most abundant in the plant kingdom).
Therefore,statements $(a)$,$(b)$,and $(c)$ are correct.

(B) The correct answer is $B$.
$1$. Chitin is a complex polysaccharide (carbohydrate) found in the exoskeleton of arthropods and fungal cell walls.
$2$. Pectin is a structural heteropolysaccharide (carbohydrate) found in the primary cell walls of terrestrial plants. It is not a protein.
$3$. Steroids are a class of lipids characterized by a carbon skeleton with four fused rings.
$4$. Waxes are esters of long-chain fatty acids with long-chain alcohols,classified as lipids.
Therefore,the pair $Pectin - Protein$ is incorrect.

(C) Water in the protoplasm exists in two primary forms:
$1$. Free water: This constitutes the majority of the water content and acts as a solvent for various metabolic reactions.
$2$. Bound water: This is the water that is chemically or physically associated with macromolecules like proteins and carbohydrates,helping in maintaining their structural integrity.
Therefore,both free and bound forms are present in the protoplasm.

(C) Chain-growth polymerization involves the addition of monomer units to a growing chain,typically through a radical,cationic,or anionic mechanism.
$Polystyrene$ is a synthetic polymer formed by the addition polymerization of styrene monomers.
Starch,nucleic acids,and proteins are natural biopolymers formed through condensation polymerization (step-growth),where small molecules are eliminated during the formation of bonds like glycosidic,phosphodiester,or peptide bonds.

(C) Vitamin $C$,also known as ascorbic acid,is a water-soluble vitamin found abundantly in citrus fruits. Among the given options,oranges are a rich source of Vitamin $C$. While other fruits and vegetables contain trace amounts,citrus fruits like oranges,lemons,and amla are primary dietary sources.

(C) Thiamine is the chemical name for Vitamin $B_1$.
It is a water-soluble vitamin that plays a crucial role in energy metabolism and the proper functioning of the nervous system.
Deficiency of Vitamin $B_1$ can lead to a disease known as beriberi.

(D) The $Vitamin$ $B$ complex consists of a group of water-soluble vitamins, including $B_1$ (Thiamine), $B_2$ (Riboflavin), $B_3$ (Niacin/Nicotinic acid), $B_5$ (Pantothenic acid), $B_6$ (Pyridoxine), $B_7$ (Biotin), $B_9$ (Folic acid), and $B_{12}$ (Cyanocobalamin).
$Tocopherol$ is the chemical name for $Vitamin$ $E$, which is a fat-soluble vitamin and not part of the $Vitamin$ $B$ complex.
Therefore, the correct option is $D$.

(A) The correct pair is $A$ (Retinol : Xerophthalmia).
$1$. Retinol (Vitamin $A$) is a fat-soluble vitamin. Its deficiency leads to Xerophthalmia (dryness of the eyes).
$2$. Cobalamin (Vitamin $B_{12}$) is water-soluble; its deficiency causes pernicious anemia,not Beri-beri (which is caused by Vitamin $B_1$ deficiency).
$3$. Calciferol (Vitamin $D$) is fat-soluble; its deficiency causes Rickets or Osteomalacia,not Pellagra (which is caused by Vitamin $B_3$ deficiency).
$4$. Ascorbic acid (Vitamin $C$) is water-soluble; its deficiency causes Scurvy. Although the disease is correctly matched,the vitamin is water-soluble,not fat-soluble.

(B) Vitamins are classified into two categories based on their solubility: fat-soluble and water-soluble.
Fat-soluble vitamins include Vitamin $A$,$D$,$E$,and $K$.
Water-soluble vitamins include Vitamin $B$ complex and Vitamin $C$.
Therefore,Vitamin $B$ is a water-soluble vitamin.

(B) Glycogenolysis is the biochemical process of breaking down glycogen into glucose$-1-$phosphate and glucose. This process primarily occurs in the $Liver$ and $Muscle$ tissues. However,the $Liver$ is the primary organ responsible for maintaining blood glucose levels by releasing glucose into the bloodstream through glycogenolysis,as it contains the enzyme glucose$-6-$phosphatase,which muscle cells lack. Therefore,the $Liver$ is the most appropriate answer in the context of systemic glucose regulation.

(A) Vitamin-$C$ is chemically known as Ascorbic acid. It is a water-soluble vitamin that acts as an antioxidant and is essential for the synthesis of collagen,neurotransmitters,and carnitine. Deficiency of Vitamin-$C$ leads to a disease called scurvy.