Chapter 8

Question 1

What is metabolism? (2)

Answer 1

Totality of an organism’s chemical reaction

Emergent property of life

Question 2

What is a metabolic pathway? (3)

Answer 2

Begins with a specific molecule

altered in a series of defined steps, with each step catalyzed by an enzyme

results in a certain product

Question 3

What is a catabolic pathway, and an example? (

Answer 3

Processes that breakdown molecules to release energy

ex- Cellular respiration

Question 4

What is an anabolic pathway, and an example?

Answer 4

consumes energy to build complicated molecules
ex- photosynthesis

Question 5

What is bioenergetics?

Answer 5

study of how energy flows through living organisms

Question 6

What is energy?

Answer 6

Capacity to cause change.

Question 7

What is kinetic energy?

Answer 7

Relative motion of objects

Question 8

What is thermal energy?

Answer 8

Kinetic energy associated with the random movement of atoms or molecules

Question 9

What is heat?

Answer 9

transfer of thermal heat

Question 10

What is potential energy?

Answer 10

energy matter possesses because of its location or structure

Question 11

What is chemical energy?

Answer 11

potential energy available for release in a chemical reaction

Question 12

What is thermodynamics?

Answer 12

Study of energy transformations that occur in a collection of matter

Question 13

What is an isolated system?

Answer 13

a system unable to exchange either energy or matter with its surroundings

Question 14

What is an open system and an example?

Answer 14

a system able to exchange energy and matter with its surroundings
ex- organisms

Question 15

What is the first law of thermodynamics?

Answer 15

energy can be transferred or transformed, but it cannot be created or destroyed

Question 16

What is the second law of thermodynamics?

Answer 16

every energy transfer or transformation increases the entropy of the universe

Question 17

What is entropy?

Answer 17

Measure of disorder

Question 18

What is a spontaneous process (2)

Answer 18

if a given process leads to an increase in entropy, the process proceeds without requiring an input of energy

energetically favorable

Question 19

What is free energy?

Answer 19

portion of a system’s energy that can perform work when temp and pressure are uniform throughout the system

Question 20

What does the sign of free energy mean?

Answer 20

Negative free energy indicates a spontaneous reaction

Question 21

How do free energy and a spontaneous reaction correlate?

Answer 21

Every spontaneous reaction decreases the system’s free energy

Question 22

What does an increase in free energy mean? (2)

Answer 22

less stable

Greater work capacity

Question 23

How does equilibrium affect free energy?

Answer 23

A process is spontaneous and can perform work only when it is moving toward equilibrium

Question 24

What is an exergonic reaction and an example? (3)

Answer 24

Releases energy

spontaneous

ex- loss of energy due to breaking down of molecules

Question 25

What is an endergonic reaction? (2)

Answer 25

Absorbs free energy from its surroundings

nonspontaneous

Question 26

What is chemical work in the body?

Answer 26

Pushing of endergonic reaction

Question 27

What is transport work in the body?

Answer 27

pumping of substances across membranes against the direction of spontaneous movement

Question 28

what is mechanical work in the body?

Answer 28

• beating of celia, contraction of muscles

Question 29

What is energy coupling and an example?

Answer 29

use of an exergonic process to drive an endergonic one

ex- ATP used in reactions

Question 30

What is adenosine triphosphate made up of, and how does it work?

Answer 30

contains one sugar ribose, adenine, and three phosphate groups

Works by breaking the phosphate group by hydrolysis, turning into ADP

Question 31

What is a phosphorylated intermediate?

Answer 31

recipient molecule with the phosphate group from a hydrolyzed ATP

Question 32

what is activation energy?

Answer 32

Initial energy required for starting a reaction

Question 33

What is a transition state?

Answer 33

when molecules have absorbed enough energy for bonds to break, causing reactants to be in an unstable condition

Question 34

Why can’t heat be the source of activation energy in cells? (2)

Answer 34

Heat will denature proteins and kill cells

It will speed up all reactions, not just those that are needed

Question 35

What is a substrate?

Answer 35

The reactant an enzyme acts on

Question 36

What is an active site?

Answer 36

region of an enzyme where it binds to a substrate

Question 37

What is an induced fit?

Answer 37

when an enzyme slightly changes shape due to interactions between the substrate and the active site, binding them tighter

Question 38

What is a cofactor?

Answer 38

Nonprotein molecules that help enzymes catalyze

Question 39

What is a coenzyme?

Answer 39

Organic cofactors

Question 40

What is a competitive inhibitor and how is it overcome?

Answer 40

reduce the productivity of enzymes by blocking substrates from entering active sites

Overcome by increasing concentration of substrate

Question 41

what is a noncompetitive inhibitor?

Answer 41

binds to a an enzyme away from the active sit to alter the shape of the enzyme

Question 42

What is an allosteric regulation?

Answer 42

when a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site

Question 43

what is cooperativity?

Answer 43

when a substrate binds to one active site of a multisubunit enzyme to trigger a shape change to increase catalytic activity

Question 44

What is feedback inhibition?

Answer 44

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