Chapter 8

Question 1

Metabolism

Answer 1

Transforms matter and energy (subject to the law of thermodynamics)

Question 2

Metabolic pathways are diverse with respect to

Answer 2

• the length of the pathway
• the organization of the pathway
• how the pathway is regulated

Question 3

Isolated System

Answer 3

Unable to exchange energy or matter with its surroundings

Question 4

Open System

Answer 4

Energy and matter can be transferred between the system and its surroundings
-Ex: Organisms

Question 5

First Law of Thermodynamics

Answer 5

Energy cannot be created nor destroyed

• Relates to the amount of energy in the universe
• Ex: Chemical energy in food
• Harness PE to do work

Question 6

Second Law of Thermodynamics

Answer 6

During every energy transfer, some energy is unusable and often lost in the form of heat

• Reveals efficiency of an energy transformation (does not occur with 100% efficiency)
• Heat (KE)= can be harnessed to do work but only when there is a heat gradient (NOT in cells)

Question 7

Enzyme Class: Oxidoreductase

other names: Oxidase, Reductase, Dehydrogenase

Answer 7

Reaction Type: Electron Transfer

-Catalyzes reaction where 1 molecule is oxidized and the other is reduced

Question 8

Enzyme Class: Transferase

Answer 8

Reaction Type: Transfers functional groups from one molecule to another
(ex: taking terminal phosphate from ATP and tranferring it to a portion of a protein, which is the sodium potassium pump)

Question 9

Enzyme Class: Hydrolases

Answer 9

Reaction Type: Hydrolysis of one molecule into more than one molecule

• Catalyzes hydrolytic cleavage
• Found within lysosome
• Perform optimally in acidic environments
• Can be used to break covalent bonds

Question 10

Enzyme Class: Lyase

Answer 10

Reaction Type: Removal/addition of a group into a molecule

-Removal/Addition rather than transport –> used to create modified molecule

Question 11

Enzyme Class: Isomerase

Answer 11

Reaction Type: Movement of functional group within a molecule

• Related to isomers
• Catalyze arrangement of bonds within a single molecule
• Used to move functional groups within a molecule, rather than one molecule to another

Question 12

Enzyme Class: Ligase

Answer 12

Reaction Type: Joins two molecules together

- Energy dependent process
ex: extend 2 DNA molecules together through phosphodiesther bonds

Question 13

Cofactors

Answer 13

Nonprotein enzyme helpers

• May be inorganic (metal in ionic form) or organic (vitamins)
• Coenzyme= organic cofactor

Question 14

Q) All of the following are ways to regulate an enzyme except:
A. Dephosphorylation by a phosphatase
B. The binding of a substrate
C. Allosteric activation
D. Addition of a phosphate group
E. All of the above are mechanisms for regulation

Answer 14

A) E. All of the above are mechanisms for regulation

Question 15

Catabolic Pathways

Answer 15

• Large molecules are broken down into smaller ones

- Generate energy by breaking down larger molecules

Question 16

Anabolic Pathways

Answer 16

• Taking blocks and building larger, more complex molecules

- Require energy to synthesize larger molecules

Question 17

Anabolic and Catabolic Pathways

Answer 17

Required for maintaining the cell’s energy balance