Biomolecules Biology Quiz for NEET

No. of Questions in Quiz	36 with Explanation
Time for each Questions	60 Seconds
Attempts Allowed	Unlimited
Available	Always
Pass Percentage	70 %

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#1. The two functional groups characteristic of sugars are

Hydroxyl and methyl

Carbonyl and methyl

Carbonyl and hydroxyl

Carbonyl and phosphate

Sugar is a common term used to denote carbohydrate.

Carbohydrates are polyhydroxy aldehyde, ketone or their derivatives, which means they have carbonyl and hydroxyl groups.

#2. Which one of the following statements is correct, with reference to enzymes?

Apoenzyme = Holoenzyme + Coenzyme

Holoenzyme = Apoenzyme + Coenzyme

Coenzyme = Apoenzyme + Holoenzyme

Holoenzyme = Coenzyme + Cofactor

Holoenzyme is conjugated enzyme in which protein part is apoenzyme while non-protein is cofactor.

Coenzyme are also organic compounds but their association with apoenzyme is only transient and serve as cofactors.

#3. A non-proteinaceous enzyme is

Lysozyme

Ribozyme

Ligase

Deoxyribonuclease

Ribozyme is RNA acting like an enzyme or biocatalyst.

#4. The chitinous exoskeleton of arthropods is formed by the polymerisation of

Lipoglycans

Keratin sulphate and chondroitin sulphate

D-glucosamine

N-acetyl glucosamine

Exoskeleton of arthropods is made up of chitin. Chitin is a homopolymer of N-acetyl glucosamine.

#5. Which one of the following is not applicable to RNA?

Chargaff's rule

Complementary base pairing

5' phosphoryl and 3' hydroxyl ends

Heterocyclic nitrogenous bases

Chargaff’s rule is applicable only for dsDNA.

#6. Macromolecule chitin is

Phosphorus containing polysaccharide

Sulphur containing polysaccharide

Simple polysaccharide

Nitrogen containing polysaccharide

Chitin is a polymer of N-acetyl glucosamine.

#7. Telomerase is an enzyme which is a :

Repetitive DNA

RNA

Simple protein

Ribonucleoprotein

#8. Which of the following are not polymeric?

Nucleic acids

Proteins

Polysaccharides

Lipids

Nucleic acids are polymers of nucleotides – Proteins are polymers of amino acids – Polysaccharides are polymers of monosaccharides – Lipids are the esters of fatty acids and alcohol

#9. Which of the following is the least likely to be involved in stabilizing the three-dimensional folding of most proteins?

Hydrogen bonds

Electrostatic interaction

Hydrophobic interaction

Ester bonds

Ester bond is formed between sugar and phosphate in a nucleotide.

#10. A typical fat molecule is made up of

Three glycerol and three fatty acid molecules

Three glycerol molecules and one fatty acid molecule

One glycerol and three fatty acid molecules

One glycerol and one fatty acid molecule

A typical fat molecule is triglyceride formed by esterification of one glycerol and three fatty acid molecules.

#11. Which one of the following statements is wrong?

Glycine is a sulphur containing amino acid

Sucrose is a disaccharide

Cellulose is a polysaccharide

Uracil is a pyrimidine

Glycine is simplest amino acid in which ‘R’ is replaced by H(Hydrogen).

#12. Which of the following biomolecules does have a phosphodiester bond?

Nucleic acids in a nucleotide

Fatty acids in a diglyceride

Monosaccharides in a polysaccharide

Amino acids in a polypeptide

Phosphodiester bond is formed between two nucleotides of nucleic acid.

#13. Which one of the following statements is incorrect?

The presence of the competitive inhibitor decreases the Km of the enzyme for the substrate

A competitive inhibitor reacts reversibly with the enzyme to form an enzyme-inhibitor complex

In competitive inhibition, the inhibitor molecule is not chemically changed by the enzyme

The competitive inhibitor does not affect the rate of breakdown of the enzyme-substrate complex

The presence of competitive inhibitor increases Km value of enzymes

#14. Select the option which is not correct with respect to enzyme action:

Substrate binds with enzyme at its active site

Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate

A non - competitive inhibitor binds the enzyme at a site distinct from that which binds the substrate

Malonate is a competitive inhibitor of succinic dehydrogenase

Inhibition of succinic dehydrogenase by malonate is an example of competitive inhibition. This is reversible reaction. On increasing the substrate (succinate) concentration the effect of inhibitor is removed and Vmax remains the same.

#15. Which one of the following is a non - reducing carbohydrate?

Maltose

Sucrose

Lactose

Ribose 5-phosphate

Lactose, Maltose, Ribose 5-phosphate all are reducing sugars.

#16. A phosphoglyceride is always made up of:

Only an unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached

A saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached

A saturated or unsaturated fatty acid esterified to a phosphate group which is also attached to a glycerol molecule

Only a saturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached

#17. The essential chemical components of many coenzymes are:

Nucleic acids

Carbohydrates

Vitamins

Proteins

Niacin and riboflavin are used as coenzymes in NAD and FAD respectively.

#18. Transition state structure of the substrate formed during an enzymatic reaction is :

Permanent but unstable

Transient and unstable

Permanent and stable

Transient but stable

Transition state is a temporary structure formed during an enzymatic reaction.

#19. For its activity, carboxypeptidase requires

Copper

Zinc

Iron

Niacin

Carboxypeptidase requires Zn² metal ion.

#20. Which one of the following biomolecules is correctly characterised?

Alanine amino acid – Contains an amino group and an acidic group anywhere in the molecule

Lecithin – a phosphorylated glyceride found in cell membrane

Palmitic acid – an unsaturated fatty acid with 18 carbon atoms

Adenylic acid – adenosine with a glucose phosphate molecule

Option (1) is wrong, because alanine contains an amino group and an acidic group at α-carbon in the molecule.

Option (3) is wrong, because palmitic acid is a saturated fatty acid with 16C atoms.

Option (4) is wrong, because adenylic acid is form by adding phosphate group to adenosine.

#21. Three of the following statements about enzymes are correct and one is wrong. Which one is wrong?

Enzymes require optimum pH for maximal activity

Enzymes are denatured at high temperature but in certain exceptional organisms they are effective even at temperatures 80°-90°C

Enzymes are highly specific

Most enzymes are proteins but some are lipids

Most enzymes are protein but some are RNA i.e. Ribonuclease-P and ribozyme.

#22. Which one of the following pairs is wrongly matched?

Alcohol – Nitrogenase

Fruit juice – Pectinase

Textile – Amylase

Detergents – Lipase

Nitrogenase is useful in fixation of nitrogen.

#23. An organic substance bound to an enzyme and essential for its activity is called

Coenzyme

Holoenzyme

Apoenzyme

Isoenzyme

Organic compound which bound to an enzyme is either coenzyme or prosthetic group.

#24. Which of the following is the simplest amino acid?

Tyrosine

Asparagine

Glycine

Alanine

In glycine, the R-group is replaced by hydrogen.

#25. Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these

Enhance oxidative metabolism

Are conjugated proteins

Are exclusively synthesized in the body of a living organism as at present

Help in regulating metabolism

(1) is incorrect, because enzymes can both enhance and inhibit the oxidative metabolism.

(3) is incorrect, different enzymes, vitamins and hormones are synthesized in the body at different situations.

(2) is incorrect, because all hormones and enzymes are not conjugated protein.

#26. Carbohydrates, the most abundant biomolecules on earth, are produced by

All bacteria, fungi and algae

Fungi, algae and green plant cells

Some bacteria, algae and green plant cells

Viruses, fungi and bacteria

Autotrophic organism produce glucose by photosynthesis which is a carbohydrate. Heterotrophies are dependent on autotrophs and don’t produce carbohydrates and fungi are saprobic organisms.

#27. Which of the following statements regarding enzyme inhibition is correct ?

Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein

Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme

Non-competitive inhibitors often bind to the enzyme irreversibly

because a competitive inhibitor has a similar structure as that of a substrate, so it blocks the active site of an enzyme thereby reducing the production formation.

#28. The catalytic efficiency of two different enzymes can be compared by the

The Km value

The pH optimum value

Formation of the product

Molecular size of the enzyme

Enzymes with low Km are considered as good enzymes due to their high affinity for substrates.

#29. The four elements that make up 96% of all the elements found in a living system are

C, H, O and P

C, N, O and P

H, O, C and N

C, H, O and S

% weight of human body : C = 18.5; O = 65.0; N = 3.3; H = 0.5

#30. High cholesterol patients are advised to use

Ghee, butter and oils

Groundnut oil, margarine and vegetable oils

Fatty oil and butter

Cheese, dalda and ghee

These oils contain polyunsaturated fatty acids (i.e. more than one double bond) and they are usually recommended by doctors to person having hypertension, high blood cholesterol and other cardiovascular diseases.

#31. Essential amino acid is

Phenylalanine

Glycine

Aspartic acid

Serine

Essential amino acids are leucine, isoleucine, valine, tryptophane, phenylalanine, lysine and methionine.

#32. Lipids are insoluble in water because lipid molecules are

Hydrophilic

Hydrophobic

Neutral

Zwitter ions

Hydro-means water, phobic – means repeling or hating

Lipids are hydrophobic that’s why they are not soluble in water.

#33. The major role of minor elements inside living organisms is to act as

Co-factors of enzymes

Building blocks of important amino acids

Constituents of hormones

Binders of cell structure

Minor elements basically includes Zn, Mg, K, Ni, Co, NAD,NADP they all come under the category of cofactor.

#34. Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by

Base-sugar-phosphate

Base-sugar-OH

(Base-sugar-phosphate)n

Sugar-phosphate

Nucleotide : Base Sugar Phosphate

Nucleic acid : (Base Sugar Phosphate)n

#35. About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and

Sulphur and magnesium

Magnesium and sodium

Calcium and phosphorus

Phosphorus and sulphur

#36. Which of the following is a neutral amino acid?

Glutamine

Arginine

Valine