Chapter 8 Biology Review

Front 1

Definition of Metabolism

Back 1

All the chemical changes that occur in an organism

Front 2

Enzyme

Back 2

serve as catalysts (chemical agents that change the rate of reaction without being consumed)

Front 3

Catabolic metabolism

Back 3

Breaks down complex molecules to simpler compounds. Breaking bonds releases energy

Front 4

Anabolic metabolism

Back 4

Consumes energy to build complex molecules from simpler ones. Forming bonds requires energy.

Front 5

Energy coupling

Back 5

interaction between catabolic and anabolic pathways

catabolic pathways often energize anabolic ones

Front 6

Energy

Back 6

The ability to rearrange a collection of matter, the capacity to do work

Front 7

Kinetic Energy

Back 7

when energy is associated with the relative motion of objects

Front 8

Potential Energy

Back 8

the energy present due to an object's position or composition

Front 9

Chemical Energy

Back 9

potential energy available for release in a chemical reaction

Front 10

Thermodynamics

Back 10

The study of energy transformations that occur in a collection of matter

Front 11

1st Law of Thermodynamics

Back 11

Energy can be transferred and transformed but it cannot be created or destroyed. Conservation of energy

Front 12

2nd Law of Thermodynamics

Back 12

Every energy transformation or transfer increases the entropy of the universe.

Front 13

Entropy

Back 13

Measure of disorder, takes the form of heat

Front 14

Free Energy (G)

Back 14

Portion of a system's energy that is available to perform work. All molecules have free energy

Front 15

Equation for change in free energy (∆G)

Back 15

∆G= ∆H - T∆S

H= total energy

T= absolute temperature in Kelvin

S= system's entropy

Front 16

Spontaneous Reaction

Back 16

Occurs without energy, ∆G < 0

Front 17

Non-spontaneous Reaction

Back 17

Requires energy to proceed, ∆G > 0

Front 18

Exergonic reaction

Back 18

∆G < 0, reactions proceed with a net release of free energy

Front 19

Endergonic reaction

Back 19

∆G > 0, reactions absorb free energy from the environment

Front 20

Cellular respiration

Back 20

C6H12O6 (sugar) + 6O2 yields 6CO2 and 6H2O

Exergonic

∆G= -686 kcal/mol per 180 grams of glucose

Front 21

ATP

Back 21

Adenosine triphosphate, source of energy that drives cellular work

Front 22

Structure of ATP

Back 22

1. Adenine nitrogenous base

2. Ribose sugar

3. 3 phosphate groups

Front 23

Where is the energy stored in ATP?

Back 23

between the bonds of the three phosphates

Front 24

How does ATP perform work?

Back 24

Water hydrolyzes terminal phosphate bond and a molecule of inorganic phosphate is removed (exergonic)

∆G= -7.3 kcal/mol

Front 25

What happens to the phosphate removed from ATP?

Back 25

Phosphate group is transferred to some other molecule with the help of an enzyme (phosphorylated)

Front 26

Energy coupling

Back 26

Cell uses energy released by ATP hydrolysis to drive endergonic reactions

Front 27

How is ATP regenerated?

Back 27

Addition of a phosphate to ADP

Front 28

What enzyme hydrolyzes sucrose into glucose and fructose?

Back 28

Sucrase

Front 29

How do catalysts increase the rate of reactions?

Back 29

They lower the activation energy

Front 30

Substrates

Back 30

Substances on which the enzyme will work. Enzymes pick specific ones

Front 31

Active site

Back 31

Place on enzyme on which substrate binds, pocket or groove on surface of protein

Front 32

3 Factors Affecting Enzyme Activity

Back 32

1. Environmental conditions

2. Cofactors

3. Inhibitors

Front 33

Environmental factors affecting enzyme activity

Back 33

1. Temperature

2. pH Level

3. Salt concentration

Front 34

Cofactors

Back 34

Non-protein helpers for catalytic activity

Front 35

Inorganic cofactors

Back 35

metal atoms (zinc, iron, copper)

Front 36

Organic molecules

Back 36

Coenzymes (vitamins)

Front 37

Competitive Inhibitor

Back 37

Competes with substrate for active site, interfering with enzyme activity

Front 38

How to overcome competitive inhibitor

Back 38

Increase amount of substrate so there is more substrate than competitive inhibitor

Front 39

Non-competitive Inhibitor

Back 39

Does not directly compete for active site, but changes shape of active site when it attaches to allosteric site

Front 40

Activators

Back 40

Makes products faster, process runs more smoothly

Front 41

Feedback Inhibition

Back 41

Near the end of a process, final product will recognize that there is an abundance of such product. Binds to first enzyme at allosteric site and halts process