LATEST AQA A LEVEL BIOLOGY PAPER 1
COMPREHENSIVE TEST PAPER 2026
COMPLETE ANSWERS ACCURATE
⫸ Describe the structure of glycogen. /2 Answer: 1. Polysaccharide of
α-glucose;
OR
polymer of α-glucose;
2. (Joined by) glycosidic bonds
OR
Branched structure;
⫸ NHE3 actively transports one sodium ion into the cell in exchange
for one proton
(hydrogen ion) out of the cell.
Use your knowledge of transport across cell membranes to suggest how
NHE3
does this. /3 Answer: 1. Co-transport;
2. Uses (hydrolysis of) ATP;
3. Sodium ion and proton bind to the protein;
4. Protein changes shape (to move sodium ion
and/or proton across the membrane);
, ⫸ Explain the curves for max protease activity over time at 50C and
60C. /4 Answer: 1. Both denatured (by high temperature);
2. Denaturation faster at 60 °C due to more (kinetic) energy;
3. Breaks hydrogen/ionic bonds (between amino acids/R groups);
4. Change in shape of the active site/active site no longer
complementary so fewer enzyme-substrate complexes formed;
⫸ Describe the action of these membrane-bound dipeptidases and
explain their
importance. /2 Answer: 1. Hydrolyse (peptide bonds) to release amino
acids;
2. Amino acids can cross (cell) membrane;
OR
Dipeptides cannot cross (cell) membrane;
OR
Maintain concentration gradient of amino acids for absorption;
⫸ Explain why the scientists suggested that patients should be treated
with both the current antibiotic and the new one.
Use information from Figure 2 (old antibiotic decreases number of
bacteria, new one decreases it more) and your knowledge of evolution of
antibiotic resistance in bacteria in your answer. /3 Answer: 1. (From Fig
2) New/old antibiotic does not kill all bacteria;
OR
COMPREHENSIVE TEST PAPER 2026
COMPLETE ANSWERS ACCURATE
⫸ Describe the structure of glycogen. /2 Answer: 1. Polysaccharide of
α-glucose;
OR
polymer of α-glucose;
2. (Joined by) glycosidic bonds
OR
Branched structure;
⫸ NHE3 actively transports one sodium ion into the cell in exchange
for one proton
(hydrogen ion) out of the cell.
Use your knowledge of transport across cell membranes to suggest how
NHE3
does this. /3 Answer: 1. Co-transport;
2. Uses (hydrolysis of) ATP;
3. Sodium ion and proton bind to the protein;
4. Protein changes shape (to move sodium ion
and/or proton across the membrane);
, ⫸ Explain the curves for max protease activity over time at 50C and
60C. /4 Answer: 1. Both denatured (by high temperature);
2. Denaturation faster at 60 °C due to more (kinetic) energy;
3. Breaks hydrogen/ionic bonds (between amino acids/R groups);
4. Change in shape of the active site/active site no longer
complementary so fewer enzyme-substrate complexes formed;
⫸ Describe the action of these membrane-bound dipeptidases and
explain their
importance. /2 Answer: 1. Hydrolyse (peptide bonds) to release amino
acids;
2. Amino acids can cross (cell) membrane;
OR
Dipeptides cannot cross (cell) membrane;
OR
Maintain concentration gradient of amino acids for absorption;
⫸ Explain why the scientists suggested that patients should be treated
with both the current antibiotic and the new one.
Use information from Figure 2 (old antibiotic decreases number of
bacteria, new one decreases it more) and your knowledge of evolution of
antibiotic resistance in bacteria in your answer. /3 Answer: 1. (From Fig
2) New/old antibiotic does not kill all bacteria;
OR
