GCSE Biology Enzymes
Enzymes are biological catalysts that speed up chemical reactions in living organisms without being changed themselves.
These questions look simple — but cost marks.
What is Enzymes?
"Enzymes are biological catalysts that speed up chemical reactions in living organisms without being used up themselves."
Why are enzymes described as biological catalysts?
Why is an enzyme specific to one substrate or a small group of substrates?
Why are enzymes described as biological catalysts?
The Lock and Key Theory
The subtrate fits into the specifically shaped active site of the enzyme.
Once broken down or combined, the products are released and the enzyme is free to reuse.
Enzymes are large proteins; if their active site changes shape, they become denatured.
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