Chapter 6 - Energy and Metabolism

Question 1

oxidation

Answer 1

• loss of electrons

* results in positive charge

Question 2

reduction

Answer 2

• gain of electrons

* results in negative charge

Question 3

catabolism

Answer 3

chemical reactions that harvest energy when bonds are broken

Question 4

anabolism

Answer 4

chemical reactions that expend energy to make new chemical bonds

Question 5

metabolism

Answer 5

all chemical reactions occurring in an organism

Question 6

ATP (definition, function, and structure)

Answer 6

• adenosine triphosphate
• the energy “currency” of cells
• portable and on-demand source of energy for endergonic reactions
• ATP structure:
• ribose, a 5-carbon sugar
• adenine
• three phosphates

Question 7

potential energy

Answer 7

• Stored energy

* Molecular bonds store energy

Question 8

kinetic energy

Answer 8

• Energy of motion

Question 9

the most common electron acceptor in biological systems

Answer 9

oxygen

Question 10

redox reactions

Answer 10

• oxidation-reduction reactions always take place together because every electron that is lost by one atom is gained by another.
• plays a key role in flow of energy through biological systems

Question 11

enzyme

Answer 11

• globular protein with one or more active sites (“pockets”)

* determines the course of metabolism by facilitating particular chemical reactions

Question 12

substrate

Answer 12

• a molecule that binds to a protein and on which the protein acts

Question 13

how an enzyme performs catalysis

Answer 13

• a substrate binds to the protein’s active site
• amino acid side groups that are close to key bonds in the substrate interact with the substrate, stressing or distorting a particular bond
• stressed bonds lower the activation energy needed to break the bond
• when bonds have been broken, or new ones formed, the substrate has been converted into its product