Introduction to enzymes

    • Enzymes is a core JC1 topic in H2 BIO A levels. This topic explores what these mostly protein molecules are. In addition, describing their structure and functions as well as how they are affected by the environment. This topic will be recurring in future topics and is a favourite concept for examinations either in the main papers or in practicals.

    A selection of materials for enzymes

    Most common phrasing errors made by students during exams

    • Increase in kinetic energy of enzymes/particles results in more collisions per unit time

    Exam tips

    • Active site (enzymes ONLY) vs binding site for the rest of the proteins
    • There is a difference between activation energy and free energy of enzymes
    • For proteins that can withstand high temperature, mostly due to disulphide bonds
    • Highlight the bonds btw R groups affected due denaturation by high temperature and/or pH
    • Denaturation have 2 meanings: For proteins, disruption of the tertiary structure, causing the protein to lose its 3D conformation. For DNA, breaking of hydrogen bonds between complimentary base pairs causing the 2 DNA strands to separate
    • When given an enzyme graph, take note of the Y axis. Is it a rate of reaction or concentration of product, even concentration of substrate and adjust answers accordingly

    BYang’s tough questions bank

    • The release of human growth hormones are known to increase as body temperature increases. Once released, they bind to their cognate receptors in target cells which result in increased metabolic activities. Whilst some question if this is a result of temperature extremes, the human growth hormone effects were not observed at low temperatures. Suggest why it would be advantageous to couple increased temperatures to human growth hormone response. [3m. Created 210923]
    • If you like to have the answer, pls head over to my YouTube channel, subscribe and leave a comment that you want the answers in any of the videos!

    Questions and other matters

    • JOIN my classes so that you can get answers to your questions. You will also be able to access TYS questions from different JCs in Singapore as well as my comments and answers.
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    • You may also be interested to know how to boost your performance for A levels.