Chapter 8

Front 1

Metabolism

Back 1

totality of an organisms chemical reactions

Front 2

Metabolic pathway

Back 2

-begins with a specific molecule which is altered in a series of defined steps, resulting in a certain product

-each step catalyzed by a specific enzyme

Front 3

Catabolic pathways

Back 3

degradative process where metabolic pathways release energy by breaking down complex molecules to simpler compunds

-energy then becomes available for the cells work

Front 4

anabolic pathways

Back 4

ie. biosynthetic pathways - consume energy to build complicated molecules from simpler ones

Front 5

Energy

Back 5

Capacity to cause change

Front 6

potential energy

Back 6

the energy that matter posses because of its location or structure

Front 7

Kinetic Energy

Back 7

Energy associate with the relative motion of objects

Front 8

Thermal Energy

Back 8

kinetic energy associated with the random movement of atoms or molecules

Front 9

Heat

Back 9

Thermal energy in transfer from one object to another

Front 10

Chemical Energy

Back 10

refers to the potential energy available for release in a chemical reaction

Front 11

Thermodynamics

Back 11

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

-system is the matter that is being studied, everything else is the surroundings

Front 12

First law of thermodynamics

Back 12

-the energy of the universe is constant, transferred or transformed, never destroyed.

- also known as the principle of conservation of energy

Front 13

Second law of thermodynamics

Back 13

Every energy transfer or transformation increases the entropy of the universe

Front 14

Entropy

Back 14

measure of disorder or randomness (chaos)

Front 15

Free energy (G)

Back 15

Portion of a system's energy that can perform work when temp and pressure are uniform throughout the system. as in a living cell

Front 16

Change in free energy formula

Back 16

ΔG = ΔH - TΔS

G- Free nergy

H- system's enthalpy (total energy)

T-Temperature in kelvins

S- system's entropy

Front 17

Exergonic Reaction

Back 17

-proceeds with a net release of free energy, making Free energy negative.

-occur spontaneously

Front 18

Endergonic Reaction

Back 18

-Absorbs free energy from its surroundings, making free energy positive

-non spontaneous

Front 19

ATP (Adenosine Triphosphate)

Back 19

-Contains the sugar ribose with a nitrogenous base of adenine and a chain of three phosphate groups bonded to it

-Bonds between phosphate groups can be broken by hydrolysis causing a molecule of phosphate to leave, which makes it become adp

Front 20

Cells harness ATP to perform what 3 types of work?

Back 20

Chemical

Trabsport

Mechanical

Front 21

phosphorylated intermediate

Back 21

the recipient molecule with the phosphate molecule that was released from the ATP covalently bonded to it

Front 22

Phophorylation

Back 22

transfer of a phosphate group from ATP to some other molecule which is called the phosphorylated intermediate

Front 23

Enzyme

Back 23

macromolecule that acts as a catalyst

Front 24

Catalyst

Back 24

chemical agent that speeds up a reaction without being consumed

Front 25

Activation Energy

Back 25

Initial investment of energy for starting a reaction (contort the molecules so the bonds break) abbreviated Ea

Front 26

enzyme's Substrate

Back 26

Reactant an enzyme acts on

Front 27

Enzyme-Substrate Complex

Back 27

enzyme that has bound to its substrate

Front 28

Active Site

Back 28

region on the enzyme where the substrate binds

Front 29

Induced Fit

Back 29

-As the substrate enter s the active site it shags shapes slightly to make it fit more snugly around the substrate with the binding becoming tighter.

-Brings chemical groups of the active site into position that enhance their ability to catalyze the chemical reaction

Front 30

Enzyme's Optimal Conditions

Back 30

each enzyme has an optimal temp, pH, and salt concentration in which it can function best favoring the most active shape for the enzyme molecule

Front 31

Cofactors

Back 31

Non-protein helpers for catalytic activity. May be bound tightly to the enzyme as permanent residents or loosely and reversible along with the substrate

Front 32

Coenzyme

Back 32

Cofactor that is an organic compound

Front 33

Competitive Inhibitors

Back 33

Bind to the active site of an enzyme competing with the substrate

Front 34

Non-Competitive Inhibitors

Back 34

bind to another part of an enzyme causing the enzyme to change shape and make the active site less effective

-example include toxins, poisons, pesticides, antibiotics

Front 35

Allosteric Regulation

Back 35

-Occurs when a regulatory molecule binds to a protein on-site and affects the protein's function at another site, either inhibiting or stimulating an enzyme's activity

-binding of an activator stabilizes the active form

-binding of an inhibitor stabilizes the inactive form of the enzyme

Front 36

Cooperatively

Back 36

Mechanism that amplifies the response of enzymes to substrates where one substrate molecule primes an enzyme to act on additional substrate molecules more readily

Front 37

Feedback Inhibition

Back 37

A metabolic pathway is halted by the inhibitory binding of its end product to an enzyme that acts early in the pathway