Chapter 8 Section 4+5

Question 1

Enzyme

Answer 1

macromolecule that acts as a catalyst that speeds up reaction w/out being consumed by the reaction

Question 2

Activation Energy

Answer 2

the initial amount of energy needed to start a reaction

Question 3

The Ea creates a ____ that determines what?

Answer 3

barrier, the speed of a reaction

Question 4

Catalysis

Answer 4

the process where enzymes reduces the Ea barrier in order for reactant molecules to reach a transition state at moderate temps.

Question 5

Substrate

Answer 5

the reactant an enzyme acts on

Question 6

Enzyme-Substrate Complex

Answer 6

when enzyme binds w/substrate

Question 7

Active Site

Answer 7

restricted region the enzyme binds to substrate

Question 8

Induced Fit

Answer 8

enzyme changes shape slightly to fit in more snuggly w/ substrate to enhance ability to catalyze

Question 9

Ways an active site can lower Ea and speed up reaction

Answer 9

• acting as a template for substrate orientation
• stressing the substrates & stabilizing the transition state
  -providing favorable microenvironment
• participating directly in catalytic reaction

Question 10

synthesis

Answer 10

active site orients substrate in correct position for reaction

Question 10

synthesis

Answer 10

active site orients substrate in correct position for reaction

Question 11

digestion

Answer 11

active site binds w/ substrate & puts stress on bonds that must be broken, making it easier to separate molecules

Question 12

What are responsible for the fit of substrate & active site & enzyme?

Answer 12

H-Bonds

Question 13

An increase in enzymes means an increase in what?

Answer 13

reaction rate

Question 14

When does a reaction level off when there is an enzyme concentration?

Answer 14

when substrate is limiting factor & not all enzymes can find substrate

Question 15

An increase in substrate means an increase in what?

Answer 15

reaction rate

Question 16

When does a reaction level off when there is an substrate concentration?

Answer 16

when all enzyme have active sites engaged, enzymes are saturated, max. rate of reaction

Question 17

Optium Temp.

Answer 17

greatest # of molecular collisons, humans 35-40 C

Question 18

Heat above Optium Temp.

Answer 18

the energy level disrupts bonds in enzymes and b/tw enzyme & substrate

Question 19

Cold Temp.

Answer 19

molecules move slower, decrease in collision b/tw enzyme & substrate

Question 20

Changes in pH

Answer 20

disrupts bonds & charged amino acids, disrupts 3D shapes

Question 21

Optimal pH

Answer 21

6-8

Question 22

Changes in Salinity

Answer 22

disrupts bonds, 3D shapes & attraction b/tw charged amino acid

Question 23

What are the types of activators

Answer 23

cofactors & coenzymes

Question 24

Cofactors

Answer 24

non-protein, small inorganic compounds & ions, bound within enzyme molecule

Question 25

Coenzymes

Answer 25

non-protein, organic molecules

Question 26

Compettive Inhibator

Answer 26

mimics substrate competing for active site

Question 27

How can a Competitive Inhibitor be overcome?

Answer 27

Increasing substrate concentration, so it out competes inhibitor for active site

Question 28

Inhibitors

Answer 28

molecules that reduce enzyme activity

Question 29

Non-Competitive Inhibitor

Answer 29

binds to site other than active site

Question 30

When an allosteric inhibitor binds w/ allosteric site, what happens to the enzyme?

Answer 30

the enzyme changes shape

Question 31

Conformational change

Answer 31

active site is no longer functional binding site

Question 32

Irreversible Inhibition

Answer 32

inhibitor permanently binds w/enzyme
-competitive
permanently binds to active site

-allosteric
permanently binds to allosteric site
permanently changes enzyme’s shape

Question 33

Allosteric Regulation

Answer 33

conformational changes by regulatory molecules

inhibitors
-keeps enzyme in inactive form

Question 33

Allosteric Regulation

Answer 33

conformational changes by regulatory molecules

inhibitors
-keeps enzyme in inactive form

Question 34

Metabolic Pathways

Answer 34

Chem reactions of life are organized in pathways, divide chem reactions into many small steps

Question 35

Feedback Inhibition

Answer 35

Regulation & coordination of production
-product is used by next step in pathway
-final product is inhibitor of earlier step
allosteric inhibitor of earlier enzyme
-no unnecessary accumulation of products

Question 36

Caspases

Answer 36

enzymes that are activated when a cell has ordered to go through apoptosis