OCR ASH020Frequently examined

Biology A H020: Enzymes Topical Past Paper Questions

OCR AS Biology A (H020) past-paper questions on Enzymes, free. This topic is frequently examined across 5 exam sessions. Sign in for the full topic-segregated question bank and AI worksheets.

Sample questions

Summer (May/Jun) 2024· 1

A student investigates the rate of catalase activity as it breaks down hydrogen peroxide into oxygen and water. The volume of oxygen released was recorded over a period of 140 seconds. The results are shown in the graph. (a) Use the graph to calculate the rate of reaction at 50 s…

Summer (May/Jun) 2023· 1

Enzymes that catalyse the removal of $ CH_{3} $ groups from cytosine bases in DNA are called TET enzymes. The rate of transcription increases when $ CH_{3} $ groups are removed from DNA. During embryo development, TET enzymes remove $ CH_{3} $ from a large number of genes. This T…

Winter (Oct/Nov) 2021· 2

(a) Mosquito nets help to prevent the spread of malaria. They are often treated with an insecticide called permethrin. Some mosquitoes have developed resistance to the insecticide permethrin. Resistant mosquitoes produce an enzyme to detoxify the permethrin. Scientists discovered…

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