Chapter 4 Micro

Front 1

Metabolism

Back 1

the chemical rxns that must take place before a cell can replicate. the sum of all chemical rxns in a cell.

Front 2

two types of metabolic rxns:

Back 2

exergonic and endergonic

Front 3

Exergonic

Back 3

energy releasing, catabolic, spontaneous, deltaG -

Front 4

endergonic:

Back 4

energy requiring, anabolic, deltaG +, non spontaneous

Front 5

What makes up a cells dry weight?

Back 5

C(50) H(8.2) O(17) N(13) P(2.5) S(1.8) = 95%

Also Na Cl K Mg Ca

Front 6

Heterotrophs

Back 6

require an organic compound as their source of Carbon. ex. chemoorganotrophs

Front 7

Autotrophs

Back 7

prokaryotes that use CO2 as their sole source of Carbon. ex. chemoorganotrophs

Front 8

Nitrogen

Back 8

2nd most abundant element. Organic and inorganic forms.

Front 9

4 types of inorganic nitrogen:

Back 9

1. Nitrate and ammonium in soil

2. NH3

3. N2

4. NO2- (nitrites)

Front 10

Obligate aerobes

Back 10

can extract energy from compounds in the presence of O2

Front 11

Obligate anaerobes

Back 11

can only extract energy in the absence of O2

Front 12

Facultative anaerobes vs aerobes

Back 12

can extract energy in the presence or absence of O2. Anaerobes have no preference, aerobes will always choose O2.

Front 13

What is energy in an organism stored as?

Back 13

ATP, 2 high energy anhydride bonds and 1 low energy ester bond.

Front 14

What is free energy?

Back 14

energy released that is available to do work.

deltaG 0' is change in free energy during a rxn

Front 15

What does 0' mean?

Back 15

obtained under standard conditions.

ph7, 25C, all reactants at 1M concentrations

Front 16

relationship between exergonic and endergonic?

Back 16

they occur simultaneously

Front 17

How do you calculate the change in free energy of a reaction?

Back 17

deltaG0' = (C + D) - (A + B)

Front 18

What can the free energy calculation tell you?

Back 18

only the direction not the rate of the rxn

Front 19

Activation energy:

Back 19

energy to break bonds and start a rxn

Front 20

How do we solve the problem of slow rxn times?

Back 20

catalysts

Front 21

Catalyst:

Back 21

a substance that lowers the activation energy of a reaction, thereby increasing the rate of the reaction

Front 22

What part of a reaction does a catalyst affect?

Back 22

Speed not anything else(deltaG, direction, equilibrium)

Front 23

How is the velocity or speed of a reaction determined?

Back 23

the energy of activation

Front 24

How do enzymes catalyze reactions?

Back 24

The E temporarily combines with the substrate forming an ES complex. The substrate binds to the enzymes active site with weak bonds (not covalent). As the reaction proceeds, the products are released and the enzyme returns to its original form.

Front 25

Why do you need complementary structures?

Back 25

complementary structures minimize weak interactions

Front 26

Catalytic power of enzymes?

Back 26

accelerate rxn rates between 10^8 and 10^20 times faster than uncatalyzed rxns. far faster than any synthetic catalyst.

Front 27

Are enzymes reversible?

Back 27

some are, others only work in one direction. the product from one enzyme is normally the substrate for another.

Front 28

two types of small non protein molecules that participate in catalysis?

Back 28

Prosthetic groups and coenzymes

Front 29

Prosthetic groups:

Back 29

bind tightly to the enzyme, typically permanently via covalent bonds.

ex. heme group in cytochrome c

Front 30

Coenzymes:

Back 30

loosely bound, one coenzyme can associate with many enzymes, most are derivatives of vitamins.

ex. NAD+/NADH from Niacin

Front 31

Example of an ES complex pathway?

Back 31

Fructose Bisphosphate Aldolase

Front 32

oxidation

Back 32

removal of an e- from a substance

Front 33

reduction

Back 33

addition of an e- to a substance

Front 34

oxidation of Hydrogen

Back 34

H -> H+ and e-

Front 35

Oxidation of ferrous iron

Back 35

Fe2+ --> Fe3+ and e-

Front 36

Oxidation vs reduction analogy

Back 36

OIL RIG

Front 37

What does a redox reaction consist of?

Back 37

e- being donated by an e- donor and accepted by an e- acceptor

Front 38

What is a half reaction?

Back 38

half reaction implies that for any oxidation reaction to occur there must also be a reduction reaction

Front 39

What is the electron donor vs acceptor?

Back 39

substance being oxidized is the e- donor.

substance being reduced is the e- acceptor

Front 40

Example of a common electron donor?

Back 40

H2

Front 41

More positive reduction potential?

Back 41

it will accept the electron from the one with the more negative reducing potential

Front 42

More negative reduction potential?

Back 42

it will donate the electron to the one with the more positive reduction potential

Front 43

Oxidation reduction pairs:

Back 43

In the pair, the oxidized form is always on the left and it will be reduced.

ex. 2H+ + 2e- ---> H2

Front 44

What does the reduction potential represent?

Back 44

E0', representing how substances vary in their tendency to become oxidized or reduced

Front 45

In the redox pair, the ___ form is always on the left and it will be _____.

Back 45

oxidized, reduced

Front 46

Oxidation Reduction Rule 1

Back 46

the reduced substance (right) of a redox couple whose reduction potential is more negative donates e- to the oxidized substance (left) of a redox couple whose potential is more positive

Front 47

What does deltaE0' represent in the electron tower?

Back 47

the difference in potential between to substances

Front 48

Oxidation rule #2

Back 48

deltaEO' is proportional to deltaGO'

Front 49

3 things fueling rxns provide for a cell...

Back 49

1. energy from oxidation rxns

2. C skeletons: 12 intermediates through 3 pathways, glycolysis, krebs, pentose

3. Reducing power such as NADH and H+

Front 50

The phases of metabolism

Back 50

Catabolism and Anabolism

Front 51

Catabolism

Back 51

aka fueling

1. degradative metabolism

2. exergonic

3. oxidative

4. deltaG = -

5. spontaneous

Front 52

anabolism

Back 52

1. biosynthetic metabolism

2. endergonic

3. reductive

4. deltaG = +

Front 53

the three subphases of anabolism

Back 53

biosynthesis

polymerization

assembly