1.6

Question 1

what is the collective term for the thousands of biochemical reactions that take place in a living cell

Answer 1

•cell metabolism

Question 2

biochemical reactions are steps in a network of metabolic pathways catalysed by…

Answer 2

•enzymes

Question 3

what are metabolic pathways

Answer 3

•metabolic pathways are integrated and controlled pathways of enzyme-catalysed reactions within the cell

Question 4

state the 2 types of reactions within metabolic pathways

Answer 4

•catabolic
•anabolic

Question 5

describe a catabolic reaction

Answer 5

•catabolic reactions BREAKDOWN large molecules into smaller molecules and RELEASE energy

•e.g respiration

Question 6

describe an anabolic reaction

Answer 6

•anabolic reactions BUILD UP small molecules into large molecules and REQUIRE energy

•e.g protein synthesis

Question 7

what is the benefit of metabolic pathways having both reversible and irreversible steps?

Answer 7

•reversible and irreversible steps allow the process to be controlled precisely

Question 8

why is it beneficial that metabolic pathways contain alternative routes?

Answer 8

•alternative routes allow steps in the pathway to be bypassed

Question 9

what are metabolic pathways controlled by?

Answer 9

•the presence or absence of particular enzymes

•regulation of the rate of reaction of key enzymes

Question 10

what is activation energy?

Answer 10

•the energy needed to break chemical bonds in the reactants AND start the chemical reaction