AQA A Level Biology Paper 1 Questions and Correct Answers Verified 2024

AQA A Level Biology Paper 1 Questions and Correct Answers Verified 2024 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;