Biology Chapter 6

Front 1

Metabolism

Back 1

Either all or a specific set of chemicals reactions occurring at the cellular level.

Front 2

How is cell structure maintained?

Back 2

Using organic molecules as building blocks.

Front 3

Factors that determine the fate of a chemical reaction:

Back 3

direction

rate

Front 4

kinetic energy

Back 4

energy associated with motion

Front 5

potential energy

Back 5

energy an object possesses due to its structure or location.

Front 6

First Law of Thermodynamics

Back 6

energy cannot be created or destroyed, but can be transformed

Front 7

Second Law of Thermodynamics

Back 7

as energy is transformed, it is converted to a lower quality form. The entropy (degree of disorder) in the system is increased.

Front 8

Symbol for total energy

Back 8

H

Front 9

Symbol for usable energy

Back 9

G

Front 10

Symbol for unusable energy

Back 10

TS

Front 11

Equation for total energy

Back 11

usable energy (G) + unusable energy (TS) = total energy (H)

Front 12

Symbol for change in free energy

Back 12

ΔG

Front 13

Determines direction of reaction

Back 13

change in free energy (ΔG)

Front 14

Exergonic Reaction

Back 14

- negative free energy change

- spontaneous

- products have less free energy than reactants

- no additional energy needed

Front 15

Endergonic reaction

Back 15

- positive free energy change

- not spontaneous

- reactants have more free energy than the products

- additional energy needed

Front 16

ATP

Back 16

- energy-carrying molecule

- not a fuel molecule

Front 17

How do exergonic and endergonic reactions work together?

Back 17

energy released by exergonic reactions supplies energy for endergonic reactions.

Front 18

Catalyst

Back 18

speeds up chemical reaction rate

Front 19

Types of catalysts

Back 19

- enzymes

- ribosomes

Front 20

How do enzymes catalize

Back 20

- provide bonding/active sites for substrates

- provide bonding sites that stress chemical bonds

Front 21

Activation energy

Back 21

- energy needed to start chemical reaction

- gets reactants to active site

- more enzymes available, less activation energy needed

Front 22

Active Site/Bonding Site

Back 22

region of enzyme where substrates bind

Front 23

Factors that alter the rates of enzyme-catalyzed reactions

Back 23

- temperature

- pH

- inhibitors

- substrate concentration

- enzyme concentration

- cofactors

- coenzymes

Front 24

Temperature

Back 24

- enzymes are optimally active within narrow (high) temp. range

Front 25

pH

Back 25

- enzymes are optimally active at a pH of 2

Front 26

Inhibitors

Back 26

- prevent binding of substrates to enzymes

- more inhibitors means fewer products at a time

Front 27

Types of Reversible Inhibitors

Back 27

- Competitive inhibitors

- Noncompetitive inhibitors

Front 28

Competitive inhibitors

Back 28

- bind nonvalently to the active site of an enzyme.

Front 29

Noncompetitive inhibitors

Back 29

- bind noncovalenty to an allosteric site of an enzyme

Front 30

Irreversible inhibitors

Back 30

- bind covalently to the active site of an enzyme

Front 31

Substrate concentration

Back 31

- higher substrate concentration = higher product formation

Front 32

Enzyme concentration

Back 32

- higher enzyme concentration = more product formation

Front 33

Cofactors

Back 33

- inorganic molecules that bind temporarily to an enzyme

- help facilitate reactions

Front 34

Coenzymes

Back 34

- organic molecules that bind temporarily to an enzyme

- NAD and FAD

Front 35

Redox Reactions

Back 35

- Oxidation

- Reduction

Front 36

Oxidation

Back 36

Removal of electrons from an tom or molecule

Front 37

Reduction

Back 37

addition of electrons to an atom or molecule

Front 38

Redox Reaction

Back 38

when electrons are removed from one atom or molecule are immediately transferred to another atom or molecule.

Front 39

Energy intermediate

Back 39

molecules that store energy that may be used to drive endergonic reactions.

Front 40

How do cells use NADH and FADH2?

Back 40

- oxidation of these two is exergonic

- oxidation of these two can be used to make ATP

Front 41

Regulation of Metabolic Pathways

Back 41

- gene regulation

- cellular regulation

- biochemical regulation

Front 42

Gene regulation

Back 42

- enzymes encoded by genes

- turning genes on and off regulates pathways

Front 43

Cellular regulation

Back 43

cell-signaling molecules (like hormones) activate enzymes.

Front 44

Biochemical regulation

Back 44

noncovaltent bonding of inhibitors to enzymes.