Chapter 6

Question 1

Metabolism

Answer 1

• emergent property
• totality of organisms’ chemical reactions

Question 2

Metabolic Pathway

Answer 2

begins with specific molecule and ends with product; each step is catalyzed by a specific enzyme.

Question 3

Catabolic Pathway

Answer 3

release energy through breaking down molecules into simple compounds

Question 4

Anabolic Pathway

Answer 4

consumes energy to build complex molecules from simple ones

Question 5

Bioenergetics

Answer 5

study of how energy flows through living organisms

Question 6

Energy

Answer 6

capacity to cause change

Question 7

Kinetic Energy

Answer 7

motion

Question 8

Heat/Thermal Energy

Answer 8

kinetic energy associated with random movements of atoms and molecules

Question 9

Potential Energy

Answer 9

energy that matters possess due to its location or structure

Question 10

Chemical Energy

Answer 10

potential energy available for reuse in a chemical reaction

Question 11

Thermodynamics

Answer 11

study of energy transformations

Question 12

In an open system energy and matter can be transferred between….

Answer 12

the system and its surroundings

Question 13

First Law of Thermodynamics

Answer 13

energy of the universe is constant

Question 14

Second Law of Thermodynamics

Answer 14

every energy transfer or transformation increases entropy of universe

Question 15

For a process to occur without energy input, it must…

Answer 15

increase entropy of the universe

Question 16

During every energy transfer or transformation some energy is…

Answer 16

unusable and lost as heat

Question 17

Entropy may decrease in an organism but the universes total entropy..

Answer 17

increases

Question 18

organisms replace ordered forms of matter and energy with…

Answer 18

less ordered forms

Question 19

Energy flows into ecosystem as light and exists…

Answer 19

in the form of heat

Question 20

What is a living system’s free energy?

Answer 20

the energy that can do work when temperature and pressure are uniform

Question 21

Change in free energy is related to change in enthalpy, ….., and ….

Answer 21

• change in entropy
• temperature

Question 22

Enthalpy

Answer 22

change in total energy

Question 23

Only processes with a negative change in free energy are

Answer 23

spontaneous

Question 24

Exergonic Reaction

Answer 24

• net release of free energy and is spontaneous
• change in free energy is negative

Question 25

Endergonic Reactions

Answer 25

- absorbs free energy from surroundings and is not spontaneous - change in free energy is positive

Question 26

Reactions in a closed system eventually reach what?

Answer 26

equilibrium

Question 27

Cells are not in equilibrium because?

Answer 27

they are open systems experiencing a constant flow of materials

Question 28

Energy Coupling

Answer 28

use of an exergonic process to drive an endergonic one - mediated by ATP

Question 29

What can break bonds among phosphate groups in ATP?

Answer 29

Hydrolysis

Question 30

What does ATP hydrolysis produce?

Answer 30

ADP, ATP hydrolysis releases energy

Question 31

Phosphorylation

Answer 31

regenerates ATP

Question 32

ATP Cycle

Answer 32

catabolic to anabolic

Question 33

Enzyme

Answer 33

macromolecule that acts as catalyst

Question 34

Activation Energy

Answer 34

energy required to start a reaction, breaks bonds in reactants

Question 35

What supplies activation energy (EA)

Answer 35

heat that reactants absorb

Question 36

Heat is what kind of catalyst and how does it affect proteins?

Answer 36

Heath is a nonselective catalyst and denatures proteins

Question 37

How do enzymes catalyze reactions?

Answer 37

lowering activation energy barrier without being consumed

Question 38

Substrate

Answer 38

reactant molecule an enzyme acts on

Question 39

Active Site

Answer 39

region where and enzyme binds to substrate

Question 40

Included fit

Answer 40

binds chemical groups of active site together

Question 41

An active site can lower .... and speed up ....

Answer 41

- activation energy - reactions

Question 42

How can you increase substrate concentration?

Answer 42

speed up enzyme catalysis

Question 43

How does enzyme saturation affect reaction speed?

Answer 43

The reaction speed is sped up by adding more enzyme

Question 44

Cofactors

Answer 44

nonprotein molecules carrying out processes too difficult for amino acids

Question 45

Competitive Inhibitors

Answer 45

bind to active site of enzyme and prvent substrate binding

Question 46

Noncompetitive Inhibitors

Answer 46

bind to alternative site on enzyme =, causing active site to become less effective

Question 47

Toxins are what kind of enzyme inhibitors?

Answer 47

Irreversible (COVALENT BONDS)

Question 48

Cooperativity

Answer 48

binding one substrate molecule to active site of one subunit, locking all other subunits into active shape.