Which biomolecule primarily provides structural support in plants
A starch
B cellulose
C glycogen
D sucrose
Cellulose forms plant cell walls and provides rigidity.
Glycogen differs from starch because glycogen is
A linear
B less branched
C highly branched
D composed of fructose
Glycogen has extensive branching for rapid energy release.
Which linkage is present in starch
A β-1,4 glycosidic
B α-1,4 glycosidic
C β-1,6 glycosidic
D α-1,2 glycosidic
Amylose contains α-1,4 linkages.
Which carbohydrate is stored in animal liver
A starch
B cellulose
C sucrose
D glycogen
Glycogen is the storage carbohydrate in animals.
Protein digestion ultimately yields
A peptides
B amino acids
C fatty acids
D nucleotides
Proteins are hydrolysed into amino acids.
Which amino acid is essential
A glycine
B alanine
C lysine
D serine
Essential amino acids must be obtained from diet.
The isoelectric point of an amino acid is the pH at which
A it is fully protonated
B it is fully deprotonated
C net charge is zero
D solubility is maximum
Zwitterion predominates at isoelectric point.
Which protein contains a heme group
A keratin
B collagen
C haemoglobin
D insulin
Heme binds oxygen in blood.
Enzyme specificity arises mainly due to
A molecular mass
B protein solubility
C shape of active site
D reaction temperature
Complementary fit with substrate.
Enzymes lower activation energy by
A raising temperature
B altering equilibrium
C stabilising transition state
D increasing entropy
Provides an alternate reaction pathway.
Which vitamin deficiency causes rickets
A vitamin A
B vitamin B₁
C vitamin C
D vitamin D
Vitamin D is required for calcium absorption.
Vitamin B₁ deficiency leads to
A pellagra
B scurvy
C beriberi
D night blindness
Vitamin B₁ is thiamine.
Which nucleic acid is responsible for protein synthesis
A DNA only
B RNA only
C both DNA and RNA
D proteins
DNA codes; RNA translates.
Messenger RNA carries information from
A ribosome to cytoplasm
B nucleus to ribosome
C cytoplasm to nucleus
D mitochondria to nucleus
mRNA conveys genetic code.
Which natural product acts as an antipyretic
A quinine
B morphine
C aspirin
D nicotine
Aspirin reduces fever and pain.
Aspirin is chemically
A acetylsalicylic acid
B salicylic acid
C benzoic acid
D phenyl acetate
Acetylated derivative of salicylic acid.
Which compound is obtained from cinchona bark
A morphine
B quinine
C caffeine
D atropine
Used as antimalarial drug.
Terpenes generally contain how many carbon atoms per unit
A 3
B 4
C 5
D 6
Based on isoprene (C₅H₈) units.
Which vitamin is also known as tocopherol
A vitamin A
B vitamin C
C vitamin E
D vitamin K
Vitamin E acts as antioxidant.
Which polymer is formed by condensation polymerisation
A polyethylene
B PVC
C nylon-6,6
D polystyrene
Small molecule (water) is eliminated.
Polymerisation of ethene produces
A PVC
B polypropylene
C polyethylene
D polystyrene
Addition polymerisation of ethene.
Which polymer is commonly used for food packaging
A bakelite
B nylon
C polythene
D rubber
Flexible and inert.
Which property increases on vulcanisation
A softness
B solubility
C elasticity
D plasticity
Sulphur cross-links improve elasticity.
Which polymer is used in making fishing nets
A rayon
B nylon
C PVC
D polystyrene
High tensile strength and durability.
Which polymer is a copolymer
A polyethylene
B PVC
C buna-S
D polystyrene
Copolymer of butadiene and styrene.
Biodegradable polymers are preferred because they
A are cheaper
B are stronger
C reduce environmental pollution
D are non-toxic
They decompose naturally.
Which polymer is used for surgical sutures
A nylon
B polythene
C PVC
D bakelite
Strong and biocompatible.
Which polymer is rigid and heat resistant
A rubber
B polythene
C bakelite
D rayon
Thermosetting polymer.
Which biomolecule is mainly responsible for catalysis
A carbohydrates
B proteins
C lipids
D nucleic acids
Enzymes are proteins.
Which enzyme is present in saliva
A pepsin
B trypsin
C amylase
D lipase
Digests starch.
Which natural polymer forms spider silk
A cellulose
B protein
C rubber
D starch
Silk is a fibrous protein.
Which vitamin is synthesised in skin by sunlight
A vitamin A
B vitamin B
C vitamin C
D vitamin D
UV light converts precursors to vitamin D.
Which nucleic acid is single-stranded
A DNA
B RNA
C both DNA and RNA
D neither
RNA is usually single-stranded.
Which polymer is also known as polyamide
A polyester
B nylon
C PVC
D rubber
Amide linkages are present.
The monomer of natural rubber is
A ethene
B styrene
C isoprene
D propene
cis-1,4-polyisoprene.
Which substance is added to rubber to prevent oxidation
A sulphur
B plasticiser
C antioxidant
D catalyst
Prevents ageing and cracking.
Which polymer is used in making synthetic wool
A nylon
B rayon
C acrylic
D polyester
Acrylic fibres resemble wool.
Which carbohydrate gives blue colour with iodine
A glucose
B fructose
C starch
D sucrose
Iodine fits into amylose helix.
Which protein hormone regulates blood sugar
A adrenaline
B insulin
C thyroxine
D cortisol
Insulin lowers blood glucose.
Which natural product is used as local anaesthetic
A caffeine
B cocaine
C nicotine
D morphine
Cocaine has anaesthetic properties.
Which polymer is recyclable
A bakelite
B nylon
C thermoplastics
D thermosets
Can be remoulded on heating.
Which biomolecule forms antibodies
A carbohydrates
B lipids
C proteins
D nucleic acids
Antibodies are immunoglobulin proteins.
Which polymer is used for insulation of electric wires
A rubber
B PVC
C nylon
D rayon
Good electrical insulator.
Which vitamin helps in blood clotting
A vitamin A
B vitamin D
C vitamin E
D vitamin K
Essential for synthesis of clotting factors.
Which polymerisation does not produce by-product
A condensation
B step-growth
C addition
D hydrolysis
Only monomers add together.
Which compound is NOT biodegradable
A cellulose
B starch
C PHBV
D PVC
PVC is synthetic and non-biodegradable.
Which bond links amino acids in proteins
A glycosidic
B peptide
C ester
D phosphodiester
–CO–NH– linkage.
Which polymer is used in making seat belts
A nylon
B polyester
C polystyrene
D PVC
High strength and durability.
Which biomolecule acts as genetic material in most organisms
A RNA
B DNA
C protein
D carbohydrate
Stores hereditary information.
Correct statement is
A Proteins are polymers of nucleotides
B Nylon is a natural polymer
C Enzymes are proteins and act as catalysts
D All polymers are biodegradable
Fundamental concept of biochemistry.