Ch.5 Microbial Metabolism

Question 1

Metabolism

Answer 1

the buildup and breakdown of nutrients within a cell

Question 2

metabolism chemical reactions provide

Answer 2

energy and create substances that sustain life

Question 3

Catabolism

Answer 3

breaks down complex molecules; provides energy and building blocks for anabolism; exergonic

Question 4

Anabolism

Answer 4

uses energy and building blocks to build complex molecules; endergonic

Question 5

Metabolic pathways

Answer 5

sequences of enzymatically catalyzed chemical reactions in a cell

Question 6

metabolic pathways are determined by

Answer 6

enzymes

Question 7

enzymes are

Answer 7

encoded genes

Question 8

Collision theory

Answer 8

states that chemical reactions occur when atoms, ions, and molecules collide

Question 9

Activation energy

Answer 9

the collision energy required for a chemical reaction to occur

Question 10

Reaction rate

Answer 10

frequency of collisions containing enough energy to bring about a reaction

Question 11

reaction rate can be increased by

Answer 11

enzymes or by increasing temp., pressure, or concentration

Question 12

catalysts

Answer 12

speed up chemical reactions without being altered

Question 13

enzymes

Answer 13

are biological catalysts

Question 14

enzyme-susbstrate complex

Answer 14

substrate the enzyme’s active site

Question 15

products

Answer 15

released from the enzyme when substrate is transformed and rearranged

Question 16

Turnover number

Answer 16

the number of substrate molecules an enzyme converts to a product per second

Question 17

Oxidoreductase

Answer 17

oxidation-reduction reactions

Question 18

transferase

Answer 18

transfer functional groups

Question 19

hydrolase

Answer 19

hydrolisis

Question 20

lyase

Answer 20

removal of atoms without hydrolysis

Question 21

isomerase

Answer 21

rearrangement of atoms

Question 22

ligase

Answer 22

joining of molecules; uses ATP

Question 23

Apoenzyme

Answer 23

protein portion (inactive when alone)

Question 24

Cofactor

Answer 24

nonprotein component

Question 25

coenzyme

Answer 25

organic cofactor

Question 26

holoenzyme

Answer 26

apoenzyme plus cofactor (whole, active enzyme form)

Question 27

Factors influencing enzyme activity

Answer 27

-temp. -pH -substrate conc. -inhibitors

Question 28

high temp. and extreme pH does what?

Answer 28

denature proteins

Question 29

Saturation

Answer 29

-when the conc. of substrate is high. -enzyme catalyzes at its maximum rate

Question 30

Competitive inhibitors

Answer 30

fill the active site of an enzyme and compete with the substance

Question 31

noncompetitive inhibitors

Answer 31

interact with another part of the enzyme (allosteric site) rather than the active site in a process called allosteric inhibition

Question 32

feedback inhibition

Answer 32

end-product of a reaction allosterically inhibits enzymes from earlier in the pathway

Question 33

Ribozymes

Answer 33

RNA that function as catalysts by binding to substrates and acting upon them -not used up in the reaction -frequently used in cells to cut and splice RNA -also involved in protein synthesis in ribosomes

Question 34

Oxidation

Answer 34

removal of electrons

Question 35

reduction

Answer 35

gain of electrons

Question 36

redox reaction

Answer 36

an oxidation reaction paired with a reduction reaction

Question 37

dehydrogenations

Answer 37

biological oxidations

Question 38

ATP is generated by the

Answer 38

phosphorylation of ADP with the input of energy

Question 39

ATP is generated when

Answer 39

high-energy PO4- is added to ADP

Question 40

Chemiosmosis

Answer 40

a mechanism that uses a proton gradient across a cytoplasmic membrane to generate ATP