OCR 21st Century Science. Heya guys, I got an A* in this essay, and you can revise from this aswell

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Enzymes: By Rahma Hussein Year
In this essay, I will be stating the factors affected by enzymes, the purpose of enzymes, and
finally, the uses of enzymes.
What are Enzymes?
Enzymes are biological catalysts. They have enormous catalytic power. Catalysts are substances
that speed up reactions without being used up. Enzymes help the reactions that occur in our
bodies by controlling the rate of reaction. Enzymes are also important in respiration. Aerobic
respiration releases energy from glucose. Most enzymes are made of proteins.
They are made up of long chains of amino acids and also has a unique shape, as
shown in the picture opposite. The purpose of this is to allow another molecule
to fit with the enzyme. These molecules are known to be called substrates.
These are designed to fit into the enzymes to create a `lock-and-key' mechanism
which will then create the product molecule. Here is a picture to show how this
would look like.
As humans, enzymes also have an optimum temperature. The optimum temperature of
enzymes will vary depending on which part of the body the enzyme is present. In most cases,
the optimum temperature of enzymes is 40°. If the temperature exceeds 40°, the enzyme will
denature, as of humans, if they exceed 40°, they would die. If the enzyme denatures, it basically
means the breaking down of the active site, so the substrate cannot fit into it any more.
Enzymes don't just have an optimum temperature; they also have an optimum pH. These
diagrams will illustrate the optimum temperature and optimum pH of certain enzymes.
Rahma Hussein

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Enzymes: By Rahma Hussein Year
What factors affect enzymes?
The three factors affecting enzyme activity are: pH, temperature and substrate concentration.
Temperature is crucial for enzymes as no activity would take place if there is low temperature.
The temperature for enzymes to work at their full potential, it should be around 38-40°, this
way, reactions would take place more successfully. The second factor affecting enzymes is the
pH. The pH depends on where the enzyme is situated.…read more


lisa linsdell

Essay, which is useful not just for revising but also for writing the scientific explanation in coursework.

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