Enzymes Flashcards
What factors effect enzymes?
Temperature, ph, presence of inhibitors, concentrations of reactants and products
What are enzymes
Biological catalysts that speed up the rate of metabolic reactions
How is enzyme effected by ph?
Enzymes are sensitive to ph. Enzymes work best at particular ph. Outside this range, activity is reduced
How does temperature effect enzyme activity
Increase in temperature results in increase in enzyme activity beyond 45 degrees enzymes are denatured
Draw and label the lock and key theory of enzyme
Refer to book
Describe the lock and key theory
Enzyme is specific because only binds to particular shaped substrate, substrate active site compliments enzyme and binds to form enzyme substrate complex. Products form and differ in shape to substrate and released from enzyme
Describe the induced fit theory?
Not exact fit to substrate, instead active site is flexible and moulds to substrate, close binding results in the reaction being catalysed, products are formed and then are repelled
What are cofactors
Non protein molecules that change the enzyme structure so that it works efficiently
What are the three main groups of cofactors
Prosthetic groups, coenzymes, activators
Refer to book for info on three main groups of cofactors
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What is the activation energy?
Energy needed to start a chemical reaction
How does the presence of an enzyme effect the activation energy?
It lowers it
In many chemical reactions, heat supplies activation energy. Why would this be inappropriate for reactions that take place in cells?
May damage cells/ denature enzymes
If the amount of enzyme stays the same, the rate of reaction will increase with an increase in substrate concentration. Up to a point. Explain why this is so?
At low substrate concentration not all of the enzyme active sites are filled, at high substrate concentration all of the active sites are filled, adding more substrate will not increase the rate of a reaction
Read over book, it’s better
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