Chapter 8

Question 1

What is it called when an organism converts energy to light?

Answer 1

Bioluminescence

Question 2

What is metabolism

Answer 2

the totality of an organisms chemical reactions

Question 3

Metabolism is an emergent property of life that arises from

Answer 3

Interactions between molecules within the cell

Question 4

Metabolic pathway

Answer 4

Begins with a specific molecule and ends with a product

Question 5

each step of metabolism is catalyzed by what?

Answer 5

A specific enzyme

Question 6

Catabolic pathways

Answer 6

Releases energy by breaking down complex molecules into simpler compounds

Question 7

Cellular respiration

Answer 7

The breakdown of glucose in the presence of oxygen, is an example of a pathway of catabolism

Question 8

Anabolic pathways

Answer 8

Consume energy to build complex molecules from simpler ones

Question 9

Bioenergetics

Answer 9

The study of how organisms manage their energy resource

Question 10

Energy

Answer 10

The capacity to cause change

Question 11

Kinetic energy

Answer 11

Energy associated with motion

Question 12

Thermal energy

Answer 12

Kinetic energy associated with random movement of atoms or molecules

Question 13

Potential energy

Answer 13

Energy that matter possesses because of its location or structure

Question 14

Thermodynamics

Answer 14

The study of energy transformations

Question 15

Isolated system

Answer 15

Approximated by liquid in a thermos and is isolated from its surroundings

Question 16

Are organisms open systems?

Answer 16

Yes

Question 17

First law of thermodynamics

Answer 17

The energy of the universe is constant

Question 18

What does the first law of thermodynamics say

Answer 18

That energy can be transferred and transformed but it cannot be created or destroyed

Question 19

Second law of thermodynamics

Answer 19

Every energy transfer or transformation increases the entropy of the universe

Question 20

Spontaneous processes

Answer 20

Occurs without energy input — it can happen quickly or slowly

Question 21

What tells us whether or not a reaction occurs spontaneously

Answer 21

The free energy change of a reaction

Question 22

Free energy

Answer 22

Energy that can do work when temperature and pressure are uniform, as in a living cell

Question 23

The change in free energy (Delta G)

Answer 23

Related to the change in enthalpy

Question 24

Free energy symbol

Answer 24

Delta g

Question 25

Total energy symbol

Answer 25

Delta H

Question 26

Change in entropy

Answer 26

Delta S

Question 27

Temperature in Kelvin

Answer 27

T

Question 28

Negative delta G reactions are

Answer 28

Spontaneous

Question 29

During a spontaneous change ________

Answer 29

Free energy decreases and the stability of a system increases

Question 30

Exergonic reaction

Answer 30

A net release of free energy and is spontaneous — negative delta g

Question 31

Endergonic reaction

Answer 31

Absorbs free energy from its surroundings and is no spontaneous (positive delta G)

Question 32

Is metabolism ever at equilibrium?

Answer 32

No

Question 33

Reactions in a closed system eventually ____

Answer 33

Reach equilibrium and then do no work

Question 34

What are the three types of work that a cell does

Answer 34

Chemical - makes endergonic reactions work Transport — across the membrane Mechanical — motility of the cell

Question 35

Energy coupling

Answer 35

Cells manage energy resources through the use of an exergonic process to drive an endergonic one — this is mediated by ATP

Question 36

ATP is composed of ____

Answer 36

Ribose, adenine, and three phosphate groups

Question 37

What is cellular work powered by?

Answer 37

The hydrolysis of ATP

Question 38

How does ATP drive endergonic reactions?

Answer 38

Phosphorylation

Question 39

Catalyst

Answer 39

A chemical agent that speeds up a reaction without being consumed by the reaction

Question 40

Enzyme

Answer 40

A catalytic protein

Question 41

Activation energy

Answer 41

The initial energy needed to start a chemical reaction

Question 42

Substrate

Answer 42

The reactant that an enzyme acts on

Question 43

The active site

Answer 43

The region on the enzyme where the substrate binds

Question 44

the active site can lower an Ea barrier by

Answer 44

Orienting substrates correctly Straining substrate bonds Providing a favorable micro environment Covalently bonding to the substrate

Question 45

What can affect an enzymes activity?

Answer 45

- general environmental factors like temperature and pH - chemicals that specifically influence the enzyme

Question 46

Cofactors

Answer 46

No protein enzyme helpers

Question 47

An organic cofactor is called ____

Answer 47

A coenzyme

Question 48

Competitive inhibitors

Answer 48

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

Question 49

Noncompetitive inhibitors

Answer 49

These binds to another part of a enzyme, causing the enzyme to change space and making the active site less effective

Question 50

Altered amino acids in enzymes may ______

Answer 50

Alter their substrate specifically

Question 51

Regulation of enzyme activity is done by ___

Answer 51

Switching on or off the genes that encode specific enzymes or by regulating the activity of enzymes

Question 52

Allosteric regulation

Answer 52

May either inhibit or stimulate an enzymes activity

Question 53

Cooperatively

Answer 53

A form of allosteric regulation that can amplify enzyme activity

Question 54

Why is cooperatively allosteric

Answer 54

Because binding by a substrate to one active site affects catalysis in a different active site

Question 55

Feedback inhibition

Answer 55

The end product of a metabolic pathway shuts down the pathway

Question 56

What does feedback inhibition do?

Answer 56

Prevents a cell from wasting chemical resources by synthesizing more product than is needed