Chapter 5: Ground Rules Of Metabolism

Front 1

Alcohol Dehydrogenase

Back 1

helps the body break down toxins such as ethnol

Front 2

Energy

Back 2

the capacity to do work

Front 3

Entropy

Back 3

the measure of how much energy is dispersed

Front 4

1st Law of Thermodynamics

Back 4

energy cannot be created or destroyed

Front 5

Kinetic energy

Back 5

The energy of motion

Front 6

Potential Energy

Back 6

Stored energy

Front 7

Second Law Thermodynamics

Back 7

Energy tends to disperse spontaneously

Front 8

Activation Energy

Back 8

Minimum amount of energy required to start a reaction

Front 9

Endergonic

Back 9

describes a reaction that requires a net input of free energy to proceed

Front 10

Exergonic

Back 10

Describes a reaction that ends with a net release of free energy

Front 11

Product

Back 11

A molecule that enters a reaction

Front 12

Reactant

Back 12

a molecule that enters a reaction

Front 13

Active site

Back 13

of an enzyme, pocket in which substrates bind and a reaction occurs

Front 14

Catalysis

Back 14

the acceleration of a reaction by a molecule that is uncharged by participating in the reaction

Front 15

Induced-fit model

Back 15

the concept that substrates binding to an active site of an enzyme improves the fit between the two molecules

Front 16

Substrate

Back 16

A molecule that is specifically acted upon by an enzyme

Front 17

Transition site

Back 17

Point during a reaction at which substrate bonds reach their breaking point and the reaction will run spontaneously

Front 18

Allosteric

Back 18

Describes a region of an enzyme that can bind a regulatory molecule and is not an active site

Front 19

Electron transfer chain

Back 19

Array of enzymes and other molecules that accept and give up electrons in sequence, thus releasing the energy of the electrons in usable increments

Front 20

Feedback inhibition

Back 20

mechanism in which a change that results from some activity

Front 21

Metabolic Pathway

Back 21

series of enzyme-mediated reactions by which cells build, remodel, or breakdown an organic molecule

Front 22

Redox Reaction

Back 22

Oxidation-reduction reaction in which one molecule accepts electrons (becomes reduced) from another molecule (which becomes oxidized)

Front 23

Antioxidant

Back 23

Substance that prevents oxidation of other molecules

Front 24

ATP

Back 24

the nucleotide adenosine triphosphate

Front 25

ATP/ADP cycle

Back 25

Process by which cells regenerate ATP. ADP forms when ATP loses a phosphate group, then ATP again as ADP gains a phosphate group

Front 26

Coenzyme

Back 26

an organic molecule that is a cofactor

Front 27

Cofactor

Back 27

a metal ion or a coenzyme that associates with an enzyme and is necessary for its function

Front 28

Phosphorylation

Back 28

Transfer of a phosphate group form one molecule to another

Front 29

Adhesion Protein

Back 29

membrane protein that helps cells stick together in animal tissue

Front 30

Fluid Mosaic

Back 30

Model of a cell membrane as a two-demintional fluid of mixed composition

Front 31

Receptor Protein

Back 31

Plasma membrane protein that binds to a particular substance outside the cell

Front 32

Recognition Protein

Back 32

plasma membrane protein that identifies a cell as belonging to self

Front 33

Transport Protein

Back 33

Protein that passively or actively assists specific ions or molecules across a membrane

Front 34

Concentration

Back 34

Number of molecules or ions per unit volume

Front 35

Concentration gradient

Back 35

difference in concentration between joining regions of fluid

Front 36

diffusion

Back 36

spontaneous spreading of molecules or ions in a liquid or gas

Front 37

Hypertonic

Back 37

Describes a fluid that has a high overall solute concentration relative to another fluid

Front 38

Hypotonic

Back 38

Describes a fluid has a low overall solute concentration relative to another fluid

Front 39

Isotonic

Back 39

Describes two fluids with identical concentrations

Front 40

osmosis

Back 40

the diffusion of water across a selectively permeable membrane in response to a concentration gradient

Front 41

osmotic pressure

Back 41

Amount of turgor that prevents osmosis into cytoplasm or other hypertonic fluid

Front 42

Turgor

Back 42

Pressure that a fluid exerts against a wall, membrane, or other structure that contains it.

Front 43

Active transport

Back 43

Energy-requiring mechanism in which a transport protein pumps a solute across a cell membrane against its concentration gradient

Front 44

Calcium Pump

Back 44

Active transport protein; pumps calcium ions across a cell membrane against their concentration gradient

Front 45

Passive Transport

Back 45

Mechanism by which a concentration gradient drives the movement of a solute across a cell membrane through a transport protein. Requires no energy input.

Front 46

Endocytosis

Back 46

Process by which a cell takes in a small amount of extracellular fluid by a ballooning inward of its plasma membrane

Front 47

Exocytosis

Back 47

Process by which a cell expels a vesicles contents to extracellular fluid

Front 48

Phagocytosis

Back 48

"cell eating"; an endocytic pathway by which a cell engulfs particles such as microbes or cellular debris

Front 49

Pinocytosis

Back 49

Endocytosis of bulk materials