Course Guide Chapter 8: Introduction to Metabolism

Question 1

Define metabolism

Answer 1

the sum of all biochemical reactions that take place in an organism

Question 2

Define anabolism

Answer 2

synthetic or constructive biochemical reactions

Question 3

Define catabolism

Answer 3

degradative biochemical reactions

Question 4

Define entropy

Answer 4

measure of randomness

Question 5

Define enthalpy

Answer 5

the heat content or the total potential energy

Question 6

Define free energy

Answer 6

the portion of a system’s energy that is available to perform work when the temperature is uniform throughout the system

Question 7

What are the four conditions that favor spontaneous reactions?

Answer 7

1. decrease in enthalpy
2. increase in entropy
3. decrease in free energy
4. increase in temperature

Question 8

What are the three types of cellular work for which ATP is used?

Answer 8

1. Mechanical work
2. Active transport
3. Chemical reactions: some metabolic reactions that need energy

Question 9

What is the energy released in vitro in ATP hydrolysis?

Answer 9

-7.3 kcal/mol

Question 10

What are enzymes?

Answer 10

biological catalysts

Question 11

How do enzymes work?

Answer 11

accelerate the reaction by lowering the free energy of activation

Question 12

Define substrate

Answer 12

a reactant used by an enzyme

Question 13

Define active site

Answer 13

the site of an interaction between an enzyme and its substrate

Question 14

What are competitive inhibitors?

Answer 14

inhibitors that compete with the substrate for the same active site on the enzyme

Question 15

What are non-competitive inhibitors?

Answer 15

inhibitors that bind to the protein at some other place than the active site, changing the conformation of an enzyme and making it less active or inactive

Question 16

What are the factors that affect enzyme activity?

Answer 16

temperature, pH, salt, and substrate