In cow's milk, approximately 82% of milk protein is casein and the remaining 18% is serum Answer : (c)

Specificity is the ability of an enzyme to choose exact substrate from a group of similar chemical molecules a) Uricase, which acts only on uric acid b) Arginase, which acts only on arginine c) Carbonic anhydrase, which acts only on carbonic acid d) Lactase, which acts on lactose e) Sucrose, which acts on sucrose f) Maltase, which acts on maltose Answer : (d)

Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond. Proteases are hydrolases and specific for peptide bonds. Sucrase is a digestive enzyme that catalyzes the hydrolysis of sucrose. An amylase is an enzyme that catalyses the hydrolysis of starch A dehydrogenase (also called DH or DHase in the literature) is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor Answer : (b)

The molecule ATP (adenosine triphosphate) can function as a coenzyme. Prosthetic groups are cofactors that bind tightly to proteins or enzymes. ATP synthase is an enzyme that creates the energy storage molecule adenosine triphosphate (ATP) Adenosine triphosphate (ATP) is an organic compound Answer : (b)

Cell membrane is composed of a phospholipid bilayer, Phospholipids are esters of glycerol, fatty acids, phosphoric acid, and other alcohols. Answer : (a)

Jojoba is grown commercially to produce jojoba oil, a liquid wax ester extracted from its seed. The jojoba wax consists of extremely long (C36 - C46) straight chain entirely of mono-ethynelic linear fatty acids & monounsaturated linear fatty alcohol having high molecular weight. Answer : (b)

Uridine-5'-triphosphate (UTP) has the role of a source of energy or an activator of substrates in metabolic reactions, like that of ATP, but more specific. When UTP activates a substrate, UDP-substrate is usually formed and inorganic phosphate is released. UDP-glucose enters the synthesis of glycogen. UTP is used in the metabolism of galactose, where the activated form UDP-galactose is converted to UDP-glucose. UDP-glucuronate is used to conjugate bilirubin to a more water-soluble bilirubin diglucuronide. Answer : (d)

Lecithin is a naturally occurring fatty substance referred to as phospholipid. Answer : (d)

There are 20 different kinds of amino-acids commonly found in proteins, and most of these usually occur in any one protein molecule; they are arranged in the chain in a sequence which is exactly the same in all molecules of a given kind of protein Answer : (a)

Purine triplets such as r(A · AU), r(G · GC), and r(A · GC) form the basis of RNA triplex. Purines are generally abbreviated as R for arginine. Answer : (a)

proteins account for about 50 percent of the composition by mass, lipids (of all types) account for about 40 percent of the composition by mass, and carbohydrates account for the remaining 10 percent of the composition by mass. 70% of cell mass composed of water Now note that carbohydrate is minimum in cell and protein is maximum in cell. Now in given options, option 'b' have carbohydrate minimum and proteins maximum Answer : (b)

Cysteine is a sulphur containing amino acid having one carboxyl and one amino group. cysteine is monoamino monocarboxylic amino acid. Cystine is the amino acid which is formed by bonding together of two units of cysteine through disulphide bond. Cystine contains two carboxylic groups and two amino groups because it is formed by two units of amino acids. Hence, cystine is diamino dicarboxylic amino acid So, the correct answer is option A. Answer : (a)

Enzymes speed up the rate of chemical reactions because they lower the energy of activation, the energy that must be supplied in order for molecules to react with one another Answer : (b)

Answer:(c)

Competitive inhibition is interruption of a chemical pathway owing to one chemical substance inhibiting the effect of another by competing with it for binding or bonding. An allosteric inhibitor by binding to allosteric site alters the protein conformation in active site of enzyme which consequently changes the shape of active site. Thus enzyme no longer remains able to bind to its specific substrate. Hence enzyme is unable to perform it's catalytic activity. Non-competitive inhibition is a type of enzyme inhibition where the inhibitor reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate. Answer : (c)

Stearic acid is a saturated monobasic acid with 18 carbon-chain lengths. It is synthesized by the hydrolysis of animal fat or from hydrogenation of cottonseed or vegetable oil. Commercial stearic acid is a mixture of stearic acid with palmitic and myristic acid. Answer : (b)

The DNA and RNA Structures they are both made up of monomers called nucleotides. Answer : (a)

Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. Answer : (c)

Cofactor is a non-protein chemical compound that tightly and loosely binds with an enzyme or other protein molecules. coenzyme a non-protein compound that is necessary for the functioning of an enzyme. Answer : (a)

Name	Type of compound	Sweetness
Sucrose	Disaccharide	1.00 (reference)
Lactose	Disaccharide	0.16
Maltose	Disaccharide	0.33 – 0.45
Sorbitol	Polyalcohol	0.6
Glucose	Monosaccharide	0.74 – 0.8
Fructose	Monosaccharide	1.17 – 1.75

Sweetness of various compounds Answer : (a)

Phosphorus and calcium form insoluble hydroxyapatite crystals that give bones their rigidity. Answer : (d)

Many animals cannot synthesize linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). Linoleic acid is a doubly unsaturated fatty acid Answer : (c)

Length of one turn of DNA is 3.4 nm or 34Å Answer : (a)

A prosthetic group consisting of a protoporphyrin ring and a central iron (Fe) atom Catalases are structurally complex homo-tetrameric enzymes with one heme prosthetic group buried in each subunit The prosthetic group of peroxidase is composed of a protein-bound heme, usually through a histidine residue that acts as a proximal ligand Answer : (a)

Nucleic acids are now known to be found in all life forms including within bacteria, archaea, mitochondria, chloroplasts, and viruses Answer : (d)

Km value, Michaelis - Menten constant is defined as substrate concentration at which reaction velocity of enzyme catalysed reaction (V0) is half of the maximum velocity of this reaction (Vmax) , (i.e. Km = 1/2 Vmax) Km can vary greatly from enzyme to enzyme and even for the different substrates of the same enzyme. Answer : (a)

Aspartic acid or aspartate (Asp) and glutamic acid or glutamate (Glu). Their side chains have carboxylic acid groups Answer : (d)

Prostaglandin (PG), a C20 polyunsaturated fatty acid Answer : (b)

Macromolecule is a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer. Answer : (d)

Non-reducing agents don't have free ketone or aldehyde groups, and therefore contain an acetal instead of a hemiacetal. An acetal has two O-R groups, one –R group and a –H atom attached to the same carbon. (The key difference between an acetal and a hemiactal is that in a hemiacetal, an –OH group replaces one of the –OR acetal groups.) A sugar without a hemiacetal is non-reducing because it does not behave as a reducing agent toward oxidizing metal salts. Sucrose is one example of a non-reducing sugar. A reducing agent is a compound (like sugar) or an element (like calcium) that loses an electron to another chemical type in a redox chemical reaction. Reducing sugars, like glucose and lactose, have free ketone or aldehyde functional groups, which enable the formation of a hemiacetal, a carbon connected to two oxygen atoms: an alcohol (OH) and an ether (OR). You can oxidize a reducing sugar with mild oxidizing agents, such as metal salts. Answer : (d)

hemoglobins have 17 amino acid: alanine, glutamic acid, glycine, histidine, isoleucine, lysine, methionine, proline, tyrosineaspartic acid,leucine, serine,rginine, phenylalanine, threonine, tryptophan and valine. Answer : (d)

The proteins, being made up a diverse set of amino acids, have, in addition to carbon, hydrogen, oxygen, and nitrogen, the elements sulfur and selenium. Answer : (a)

Water molecules are joined by Hydrogen bonding Answer : (c)

Once an enzyme binds to a substrate and catalyzes the reaction, the enzyme is released, unchanged, and can be used for another reaction. This means that for each reaction, there does not need to be a 1:1 ratio between enzyme and substrate molecules. Enzymes may accelerate reactions by factors of a million or even more. Carbonic anhydrase, which catalyzes the hydration of carbon dioxide. Each molecule of the enzyme can hydrate 100,000 molecules of carbon dioxide per second. This is ten million times faster than the nonenzymecatalyzed reaction. Answewr: (a)

When two amino acids form a dipeptide through a peptide bond it is a type of condensation reaction. Answer : (d)

lactose is also known as milk sugar. Answer : (c)

Amount of energy liberated during hydrolysis of ATP of ADP is about 7,200 calories for every mole of ATP formed. Answer : (d)

Cytosine forms three hydrogen bonds with guanine, and adenine forms two hydrogen bonds with thymine. Answer : (b)

Silk is a natural protein fiber The proteins, being made up a diverse set of amino acids, have, in addition to carbon, hydrogen, oxygen, and nitrogen, the elements sulfur and selenium. Answer : (b)

The anomeric carbon is the carbon derived from the carbonyl carbon compound (the ketone or aldehyde functional group) of the open-chain form of the carbohydrate molecule Answer : (a)

The starch grains are oval eccentric in potato Oval and concentric in gram or pea; Tounded, flat and concentric in wheat and polyhedral with radiating lines in maize. Starch grains from potato cells Answer : (a)

Cellulose is derived from D-glucose units, which condense through β(1→4)-glycosidic bonds. This linkage motif contrasts with that for α(1→4)-glycosidic bonds present in starch and glycogen. Cellulose is a straight chain polymer. Answer : (d)

Answer : (d)

Nitrogenous Bases: There are two basic types of nitrogenous bases, pyrimidines and purines . These are essentially planar, hydrophobic, weak bases. Five nitrogenous bases are found in nucleic acids; adenine (A), guanine (G), and cytosine (C) are in both DNA and RNA, whereas thymine (T) is almost exclusively found in DNA, and uracil (U) almost exclusively in RNA. Answer : (d)

Pentoses and hexoses are the most common monosaccharides. Answer : (c)

Formula of Palmitic acid is C16H32O2 Formula of Stearic acid is C18H36O2 Formula of Glycerol is C3H8O3 Formula of Galactose is C6H12O6 Answer : (a)

Okra mucilage refers to the thick and slimy substance found in fresh as well as dried pods. The main components are galactose (25%), rhamnose (22%), galacturonic acid (27%) and amino acids (11%). Mannans generally occur with galactose and glucose. Answer : (d)

Monosaccharides are glucose, galactose, ribose, and glyceraldehyde. Disaccharides are Sucrose, Lactose, Maltose Trisaccharide are Nigerotriose, Maltotriose, Melezitose, Maltotriulose, Raffinose, Kestose Polysaccharides are Starch,Cellulose, Glycogen Answer : (c)

Ribosomes are a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells. Answer : (c)

At the isoelectric point, a protein has no net charge Above the isoelectric point, a protein carries a net negative charge—below it, a net positive charge. Answer : (a)