Bio Chap. 5

Front 1

Energy

Back 1

The capacity to bring about change, to do work.

Front 2

Kinetic Energy

Back 2

The energy of motion.

Front 3

Potential Energy

Back 3

Energy withe potential to do work. Stored energy.

Front 4

Chemical Reaction

Back 4

The making of breaking of chemical bonds - gluing atoms together to form new molecules, or tearing molecules apart and sometimes sticking the pieces onto other molecules

Front 5

First Law of Thermodynamics

Back 5

Energy can change from one state to another but it can never be destroyed, nor can new energy be made

Front 6

Second Law of Thermodynamics

Back 6

The disorder in a closed system like the universe is continuously increasing; entropy increases

Front 7

Entropy

Back 7

A measure of the disorder of a system. A measure of energy that has become so randomized and uniform in a system that the energy is no longer available to work.

Front 8

Reactants

Back 8

The original molecules before the chemical reaction occurs

Front 9

Substrates

Back 9

A molecule on which an enzyme acts.

Front 10

Products

Back 10

The molecules that result after the reaction has taken place

Front 11

Endergonic

Back 11

Reactions in which the products contain more energy than the reactants and require an input of usable energy from an outside source before they can proceed. These reactions are not spontaneous.

Front 12

Exergonic

Back 12

Any reaction that produces products that contain less free energy than that possessed by the original reactants and that tends to proceed spontaneously.

Front 13

Activation Energy

Back 13

The energy a molecule must acquire to undergo a specific chemical reaction

Front 14

Catalysis

Back 14

A general term for a substance that speeds up a specific chemical reaction by lowering the energy required to activate to start the reaction. An enzyme is one of these.

Front 15

Active Site

Back 15

The site on the enzyme surface where the reactant fits

Front 16

Binding Site

Back 16

The site on the reactant that binds to an enzyme.

Front 17

Biochemical Pathway

Back 17

The product of one reaction become the substrate for the next.

Front 18

Temperature Affects

Back 18

When temperature increases, the bonds that determine enzyme shape are too weak to hold it in the proper position; the rates of enzyme reactions tend to drop quickly.

Front 19

pH Affects

Back 19

Most enzymes function within an optimal pH range because the shape-determining polar interaction of enzymes are quite sensitive to hydrogen ion (H+) concentration.

Front 20

Repressor

Back 20

A protein that regulates transcription of mRNA from DNA by binding to the operator and so preventing RNA polymerase from attaching to the promotor.

Front 21

Activator

Back 21

A regulatory protein that binds to the DNA and makes it more accessible for transcription.

Front 22

Feedback Inhibition

Back 22

A regulatory mechanism in which a biochemical pathway is regulated by the amount of the product that the pathway produces

Front 23

Noncompetitive

Back 23

A molecule that binds to an allosteric site, changing the shape of the enzyme such that it is unable to bind to the substrate.

Front 24

Competitive

Back 24

A molecule that blocks the active site so that the substrate cannot bind.

Front 25

Adenosine Triphosphate (ATP)

Back 25

A molecule composed of ribose, adenine, and a triphosphate group. This is the chief energy currency of all cells. Cells focus all their energy resources on the manufacture of this from ADP and phosphate, which requires the cell to supply 7 kilocalories of energy obtained from phosynthesis or from electrons stripped from foodstuffs to form 1 mole of this. Cells then use this to drive endeergonic reactions.

Front 26

Photosynthesis

Back 26

The process by which plants, algae, and some bacteria use the energy of sunlight to create from carbon dioxide (CO2) and water (H2O) the more complicated molecules that make up living organisms.

Front 27

Cellular Respiration

Back 27

All cells convert the potential energy found in food molecules like sugar into ATP through cellular respiration.

Front 28

Enzyme-Substrate Complex

Back 28

An enzyme and its substrate(s) bind tightly together, forming this. The binding brings key atoms near each other and stresses key covalent bonds.

Front 29

Adenosine Diphosphate (ADP)

Back 29

The energy released from ATP that we use to move, think, and process chemicals.