Enzymes as Biological Catalysts

Question 1

what does an enzyme do?

Answer 1

speeds up the rate at which a reaction reaches equilibrium

Question 2

how do enzymes reduce activation energy?

Answer 2

by providing alternative pathways

Question 3

what is glycogen storage disease?

Answer 3

enzyme deficiency that results in glycogen being unable to progress to transition phosphorylated state

Question 4

what are co factors?

Answer 4

metal ions which form a coordination centre

Question 5

what are co enzymes?

Answer 5

organic molecule. Enzyme with cofactor is called a holoenzyme an enzyme without a cofactor is called a apoenzyme

Question 6

give an example of a coenzyme

Answer 6

NAD+ and FAD

Question 7

Describe induced fit model and give an example

Answer 7

when the substrate binds, a conformational change in the enzyme causes a complementary fit. Hexokinase

Question 8

What are isozymes and what do they do?

Answer 8

Isoforms of enzymes, catalyse reactions but have different properties and structure

Question 9

what is isozymes clinical use?

Answer 9

Different forms in different places suggests disease. e.g brain CK found in blood suggests stroke. Heart CK suggests heart attack

Question 10

What are zymogens? How are they activated?

Answer 10

Inactive precursors of an enzyme. Irreversibly transformed into active enzyme by cleavage of a covalent bond