AQA BIOLOGY REVISION QUESTIONS
WITH ANSWERS
Describe how you would use a biochemical test to show that a
solution contained a non-reducing sugar, such as sucrose. [3] -
CORRECT ANSWER-,first reducing sugars test; boil with dilute
HCl acid then Neutralise with NaHCǑ, add benedict and heat to
95 degrees C brick red ppt forms if reducing sugar is present
Describe a chemical test you could carry out to show that a
piece of coconut contains lipids. [3] - CORRECT ANSWER-
(Crush in) ethanol / alcohol; Add (to) water (Order of adding is
critical for this point); Emulsion / white colour
Explain what is meant by a polymer. [1] - CORRECT
ANSWER-Molecule) made up of many identical/similar
molecules/monomers/ subunits;
Name the reaction which occurs when starch is broken down
into maltose. [1] - CORRECT ANSWER-Hydrolysis
What is the formula for lactose? [2] - CORRECT ANSWER-C12
; H22Ō1
Describe how β-glucose molecule differs from a molecule of α-
glucose. [1] - CORRECT ANSWER-H at top right end (instead
of OH) / OH at bottom (carbon 1)
Show two ways in which the structure of cellulose is different
from the structure of starch. [2] - CORRECT ANSWER-Starch
1,4 and 1,6 bonds / branching Cellulose 1,4 bonds / no 1,6
bonds / straight; starch All glucoses /monomers same way up
,cellulose Alternate glucoses upside down; starch Helix /
coiled/compact cellulose Straight; Starch monomer Alpha
glucose Cellulose monomer Beta glucose
Describe the structure of starch and explain how its structure is
related to its function. [3] - CORRECT ANSWER-Formed from
α glucose; Joined by condensation/ by the removal of a water
molecule/ glycosidic bonds; Between (carbons) 1 and 4 (and 1
and 6); Coiled chain; compact; (Allows) storage of large amount
in a small space; Insoluble so has no effect on osmosis/water
potential; Branches; (Allows) rapid breakdown/release of
glucose / hydrolysis;
The structure of a phospholipid molecule is different from that
of a triglyceride. Describe how. [2] - CORRECT ANSWER-
triglyceride has three fatty acids and phospholipid has two; no
phosphate group present in triglyceride but present in
phospholipid.
What is an unsaturated fatty acid? [1] - CORRECT ANSWER-
Some / two carbons with only one hydrogen / (double bonds)
between carbon atoms / not saturated with hydrogen;
Describe the structure of cellulose and explain how its structure
is related to its function. [3] - CORRECT ANSWER-Alternate β-
glucose rotated 180o, long straight chains, Many hydrogen
bonds join (polysaccharide) chains/molecules to each other /
makes microfibrils / gives tensile strength;
Which elements are found in proteins? [1] - CORRECT
ANSWER-Carbon, hydrogen, oxygen, nitrogen (sometimes
sulphur)
Describe how you would use a biochemical test to show that a
solution contained protein. [2] - CORRECT ANSWER-Biuret /
alkali + copper sulphate; Lilac/purple/mauve/violet;
, Which bonds are found in a)Primary structure [1]b)Secondary
structure [1] c)Tertiary structure [2] - CORRECT ANSWER-
a)Peptide b) Hydrogen (and peptide) c)Ionic, disulphide
bridges, hydrophobic interactions (hydrogen and peptide)
Explain how a change in the primary structure of a globular
protein may result in a different three-dimensional structure. [3]
- CORRECT ANSWER-Sequence of amino acids changes;
tertiary structure changes/folds in a different way; bonds form in
different places (not peptide);
Describe how two-way chromatography is carried out. [2] -
CORRECT ANSWER-Run chromatogram then turn through
90/right angle; With a different solvent;
Explain the advantage of using two-way chromatography to
separate short polypeptides. [2] - CORRECT ANSWER-
Spreads spots/polypeptides out more/ make sure spot only
contains one substance;
Explain how inhibitors affect the rate of enzyme-controlled
reactions. [6] - CORRECT ANSWER-Statement about two
types, competitive and non-competitive; Competitive: Similar
shape to substrate;Inhibitor can enter/bind with active site (of
enzyme);Non-competitive: Affect/bind to enzyme other than at
active site; Distorts shape of active site; Inhibitors: Prevent
entry of/binding of substrate to active site; Therefore fewer/no
enzyme-substrate complexes formed;
Describe and explain how an increase in temperature affects
the rate of an enzyme controlled reaction. [5] - CORRECT
ANSWER-Rate of reaction increases; Increasing temperature
increases rate of movement of molecules/ kinetic energy;
Collide more often/substrate enters active site more often/more
enzyme-substrate complexes formed; Up to optimum; Rate of
reaction decreases; High temperatures cause denaturation/loss
WITH ANSWERS
Describe how you would use a biochemical test to show that a
solution contained a non-reducing sugar, such as sucrose. [3] -
CORRECT ANSWER-,first reducing sugars test; boil with dilute
HCl acid then Neutralise with NaHCǑ, add benedict and heat to
95 degrees C brick red ppt forms if reducing sugar is present
Describe a chemical test you could carry out to show that a
piece of coconut contains lipids. [3] - CORRECT ANSWER-
(Crush in) ethanol / alcohol; Add (to) water (Order of adding is
critical for this point); Emulsion / white colour
Explain what is meant by a polymer. [1] - CORRECT
ANSWER-Molecule) made up of many identical/similar
molecules/monomers/ subunits;
Name the reaction which occurs when starch is broken down
into maltose. [1] - CORRECT ANSWER-Hydrolysis
What is the formula for lactose? [2] - CORRECT ANSWER-C12
; H22Ō1
Describe how β-glucose molecule differs from a molecule of α-
glucose. [1] - CORRECT ANSWER-H at top right end (instead
of OH) / OH at bottom (carbon 1)
Show two ways in which the structure of cellulose is different
from the structure of starch. [2] - CORRECT ANSWER-Starch
1,4 and 1,6 bonds / branching Cellulose 1,4 bonds / no 1,6
bonds / straight; starch All glucoses /monomers same way up
,cellulose Alternate glucoses upside down; starch Helix /
coiled/compact cellulose Straight; Starch monomer Alpha
glucose Cellulose monomer Beta glucose
Describe the structure of starch and explain how its structure is
related to its function. [3] - CORRECT ANSWER-Formed from
α glucose; Joined by condensation/ by the removal of a water
molecule/ glycosidic bonds; Between (carbons) 1 and 4 (and 1
and 6); Coiled chain; compact; (Allows) storage of large amount
in a small space; Insoluble so has no effect on osmosis/water
potential; Branches; (Allows) rapid breakdown/release of
glucose / hydrolysis;
The structure of a phospholipid molecule is different from that
of a triglyceride. Describe how. [2] - CORRECT ANSWER-
triglyceride has three fatty acids and phospholipid has two; no
phosphate group present in triglyceride but present in
phospholipid.
What is an unsaturated fatty acid? [1] - CORRECT ANSWER-
Some / two carbons with only one hydrogen / (double bonds)
between carbon atoms / not saturated with hydrogen;
Describe the structure of cellulose and explain how its structure
is related to its function. [3] - CORRECT ANSWER-Alternate β-
glucose rotated 180o, long straight chains, Many hydrogen
bonds join (polysaccharide) chains/molecules to each other /
makes microfibrils / gives tensile strength;
Which elements are found in proteins? [1] - CORRECT
ANSWER-Carbon, hydrogen, oxygen, nitrogen (sometimes
sulphur)
Describe how you would use a biochemical test to show that a
solution contained protein. [2] - CORRECT ANSWER-Biuret /
alkali + copper sulphate; Lilac/purple/mauve/violet;
, Which bonds are found in a)Primary structure [1]b)Secondary
structure [1] c)Tertiary structure [2] - CORRECT ANSWER-
a)Peptide b) Hydrogen (and peptide) c)Ionic, disulphide
bridges, hydrophobic interactions (hydrogen and peptide)
Explain how a change in the primary structure of a globular
protein may result in a different three-dimensional structure. [3]
- CORRECT ANSWER-Sequence of amino acids changes;
tertiary structure changes/folds in a different way; bonds form in
different places (not peptide);
Describe how two-way chromatography is carried out. [2] -
CORRECT ANSWER-Run chromatogram then turn through
90/right angle; With a different solvent;
Explain the advantage of using two-way chromatography to
separate short polypeptides. [2] - CORRECT ANSWER-
Spreads spots/polypeptides out more/ make sure spot only
contains one substance;
Explain how inhibitors affect the rate of enzyme-controlled
reactions. [6] - CORRECT ANSWER-Statement about two
types, competitive and non-competitive; Competitive: Similar
shape to substrate;Inhibitor can enter/bind with active site (of
enzyme);Non-competitive: Affect/bind to enzyme other than at
active site; Distorts shape of active site; Inhibitors: Prevent
entry of/binding of substrate to active site; Therefore fewer/no
enzyme-substrate complexes formed;
Describe and explain how an increase in temperature affects
the rate of an enzyme controlled reaction. [5] - CORRECT
ANSWER-Rate of reaction increases; Increasing temperature
increases rate of movement of molecules/ kinetic energy;
Collide more often/substrate enters active site more often/more
enzyme-substrate complexes formed; Up to optimum; Rate of
reaction decreases; High temperatures cause denaturation/loss
