enzymes and metabolism

Question 1

enzymes

Answer 1

biological catalysts that are able to speed up chemical reactions by lowering the activation energy. they are not consumed or alter in the reaction

Question 2

substrate

Answer 2

the molecule on which an enzyme acts on

Question 3

active site

Answer 3

the part of the enzyme molecule that combines with the substrate - when they are combined they are called an. enzyme substrate complex

Question 4

lock and key model

Answer 4

states that the shape of an enzyme (the key) is always complementary to the shape of the substrate (the lock). therefore, the two will fit exactly to form the enzyme-substrate complex

Question 5

induced-fit model

Answer 5

states that when the enzyme and siubrate join, they form weak bonds that cause the shape of the enzyme to change, creating complementary shapes

Question 6

factors affecting enzyme activity

Answer 6

• the higher the concentration of the enzyme, the faster the rate of chemical reaction as there are more enzyme mols to influence reactants
• increasing substrate concentration will also increase the rate of reaction
• products of the reaction must be continually removed otherwise the rate of reaction will slow
• temperer - rate of chemical reactions increases as temperature increases. beyond 45-50c enzymes become denatures
• very sensitive to pH
• many require presence of cofactors - these change the shape of an active site so the enzyme can combine with the substrate
• enzyme inhibitors are substances that slow or stop enzyme activity

Question 7

cellular respiration

Answer 7

process by which organic molecules, take in by food, ar broken down in the cells to release energy for the cells activities.

Question 8

cellular respiration as an equation:

Answer 8

Glucose + oxygen —-> carbon dioxide + water + energy

C6H1206 + 602 —-> 6C02 + 6H2O + energy

Question 9

ATP

Answer 9

adenosine triphosphate
composed of adenosine and 3 phosphate group

Question 10

glycolysis

Answer 10

first phase in the breakdown go glucose - doesn’t require oxygen
- glucose mol is broken down in a sri4s of 10 steps - to 2 pyruvate molecules

Question 11

anaerobic respiration

Answer 11

if no oxygen available -