AQA A LEVEL BIOLOGY COMPREHENSIVE
TEST BANK COMPLETE QUESTIONS AND
ANSWERS PRACTICE SOLUTION VERIFIED
◉ Describe a chemical test you could carry out to show that a piece of
coconut contains lipids. [3] 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] Answer: Molecule) made
up of many identical/similar molecules/monomers/ subunits;
◉ Name the reaction which occurs when starch is broken down into
maltose. [1] Answer: Hydrolysis
◉ What is the formula for lactose? [2] Answer: C12 ; H22Ō1
◉ Describe how β-glucose molecule differs from a molecule of α-
glucose. [1] 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] 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] 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] 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] 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] 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] Answer: Carbon,
hydrogen, oxygen, nitrogen (sometimes sulphur)
, ◉ Describe how you would use a biochemical test to show that a
solution contained protein. [2] 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] 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] 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] 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] Answer: Spreads spots/polypeptides
out more/ make sure spot only contains one substance;
◉ Explain how inhibitors affect the rate of enzyme-controlled
reactions. [6] 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
TEST BANK COMPLETE QUESTIONS AND
ANSWERS PRACTICE SOLUTION VERIFIED
◉ Describe a chemical test you could carry out to show that a piece of
coconut contains lipids. [3] 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] Answer: Molecule) made
up of many identical/similar molecules/monomers/ subunits;
◉ Name the reaction which occurs when starch is broken down into
maltose. [1] Answer: Hydrolysis
◉ What is the formula for lactose? [2] Answer: C12 ; H22Ō1
◉ Describe how β-glucose molecule differs from a molecule of α-
glucose. [1] 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] 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] 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] 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] 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] 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] Answer: Carbon,
hydrogen, oxygen, nitrogen (sometimes sulphur)
, ◉ Describe how you would use a biochemical test to show that a
solution contained protein. [2] 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] 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] 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] 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] Answer: Spreads spots/polypeptides
out more/ make sure spot only contains one substance;
◉ Explain how inhibitors affect the rate of enzyme-controlled
reactions. [6] 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
