AQA A-Level Biology Paper 1 questions and answers A+ Grade|AQA A-Level Biology – Paper 1 (2026/2027)

AQA A-Level Biology Paper 1 questions and
answers 2026\2027 A+ Grade

Describe the role of a ribosome in the production of a polypeptide. /3
- correct answer 1. mRNA binds to ribosome;

2. Idea of TWO codons/binding sites;

3. tRNA with ANTICODONS binds;

4. (Catalyses) formation of PEPTIDE bond between AMINO ACIDS (held by tRNA molecules);

5. Moves along (mRNA to the next

codon);



Describe the structure of glycogen. /2
- correct 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
- correct 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
- correct 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
- correct 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
- correct answer 1. (From Fig 2) New/old antibiotic does not kill all bacteria;

OR

(From Fig 2) Some bacteria are resistant to the new/old antibiotic;

2. Resistant bacteria will reproduce to produce (more) resistant bacteria;

3. (Use of both) one antibiotic will kill bacteria resistant to the other antibiotic;

OR

Unlikely that bacteria are resistant to both the new and the old antibiotic;