Energy Metabolism

Question 1

Phototrophs use what as an energy source?

Answer 1

light

Question 2

Chemotrophs use what as an energy source?

Answer 2

oxidation of chemical compounds

Question 3

_______ use reduced inorganic substances as an energy source

Answer 3

Lithotroph

Question 4

________ obtain electrons from organic compounds

as an energy source

Answer 4

Organotrophs

Question 5

Heterotrophs use _______ as a carbon source

Answer 5

use organic molecules (i.e, glucose, amino acids, etc.)

Question 6

Autotrophs use____ as a carbon source

Answer 6

CO2

Question 7

slide 4

Answer 7

LOOK at and know

Question 8

the majority of microorganisms known are what?

Answer 8

photolithoautotrophs (photoautotrophs)

Question 9

majority of pathogens are what?

Answer 9

chemoorganoheterotrophs (chemoheterotrophs)

Question 10

Despite diversity of energy, electron, and carbon sources used by organisms, they all have the same basic needs. what are they?

Answer 10

• ATP as an energy currency
• Reducing power to supply electrons for chemical reactions
• precursor metabolites for biosynthesis

Question 11

What is Chemoorganotrophy (a.k.a. as chemoorganoheterotrophy)? (2)

Answer 11

• the complete or incomplete oxidation of an organic compound (ie, Glucose) with the subsequent release of energy
• Use of organic molecules as energy, carbon and electron source.

Question 12

what are the three known chemoheterotrophic processes in nature

Answer 12

1. ) aerobic cellular respiration
2. ) anaerobic cellular respiration
3. ) fermentation

Question 13

what is cellular respiration?

Answer 13

A complete oxidation of glucose (or other organic molecule) all the way to 6 carbon dioxides which uses an electron transport chain and an exogenous final electron acceptor of some type (oxygen or other molecule)
**inorganic carbon - no organic molecule left

Question 14

As electrons pass through the electron transport chain to the final electron acceptor, ____________ is generated and used to synthesize ATP by means of ATP synthases

Answer 14

a proton motive force (PMF)

Question 15

in aerobic cellular respiration final electron acceptor is always ______

Answer 15

oxygen

Question 16

in Anaerobic cellular respiration final electron acceptor is ________

Answer 16

never oxygen but a different exogenous acceptor such as NO3-, SO42-, CO2, Fe3+, or SeO42- organic acceptors may also be used

Question 17

In respiration, ATP made primarily by __________

Answer 17

oxidative phosphorylation (slide 12)

Question 18

describe fermentation (4)

Answer 18

slide 13

Question 19

slides 14 and 15

Answer 19

just look at

Question 20

describe catabolic pathways

Answer 20

• Enzyme catalyzed reactions whereby the product of one reaction serves as the substrate for the next
• Pathways releases energy and also provide materials for biosynthesis
• Many are amphibolic pathways

Question 21

what are amphibolic pathways? what are 3 important ones?

Answer 21

Can function both as catabolic and anabolic pathways

• Embden-Meyerhof pathway
• pentose phosphate pathway
• tricarboxylic acid (TCA) cycle

Question 22

what is aerobic cellular respiration?

Answer 22

1. ) Process that can completely catabolizes and oxidizes an organic energy source to CO2 using
   - glycolytic pathways (glycolysis) or other
   - TCA cycle or other
   - electron transport chain with oxygen as the final electron acceptor
   * *LOOK AT SLIDE 19

Question 23

what does aerobic cellular respiration produce?

Answer 23

ATP and high energy electron carriers (NADH)

Question 24

name and describe the 4 stages of aerobic cellular respiration

Answer 24

slides 20 and 21

Question 25

describe the Embden-Meyerhof Pathway | 1: where does it occur, 2: what is it, 3: does it need oxygen

Answer 25

1.) Occurs in cytoplasmic matrix of most eukaryotic microorganisms, plants, and animals -Along inner cell membrane in prokaryotes 2.) The most common pathway for glucose degradation to pyruvate in aerobic respiration, anaerobic respiration and fermentation 3.) Function in presence or absence of O2 (slides 23-28)

Question 26

what is the pathway used by soil bacteria and a few gram-negative bacteria that replaces the first phase of Embden-Meyerhof pathway? What does it yield per glucose molecule?

Answer 26

``` Entner-Duodoroff Pathway Yields: 1 ATP 1 NADPH 1 NADH ```

Question 27

describe the Pentose Phosphate Pathway (5)

Answer 27

- Also called hexose monophosphate pathway - Can operate at same time as glycolytic pathway or Entner-Duodoroff pathway - Can operate aerobically or anaerobically - An amphibolic pathway - Used by many microorganisms * slides 32-34

Question 28

describe the tricarboxylic acid cycle (3)

Answer 28

-Also called citric acid cycle and Kreb’s cycle -Common in aerobic bacteria, free-living protozoa, most algae, and fungi -A major role is as a source of carbon skeletons for use in biosynthesis and energy metabolism (slides 36-40)

Question 29

slide 41

Answer 29

confused maybe 42 will help if look at animations?

Question 30

describe the electron transport chain

Answer 30

43 and 44

Question 31

In eukaryotes the e- transport chain carriers are located in the __________, connected by ________ and _________

Answer 31

inner mitochondrial membrane; coenzyme Q and cytochrome c

Question 32

Bacterial and Archaeal ETCs are located where?

Answer 32

cell membranes

Question 33

Some bacterial and archaeal ETCS resemble mitochondrial ETC, but many are different. Name 4 reasons they may be different

Answer 33

different electron carriers may be branched may be shorter may have lower P/O ratio

Question 34

describe Paracoccus denitrificans

Answer 34

1.) Facultative, soil bacterium 2.) Extremely versatile metabolically 3.) Under oxic conditions, uses aerobic respiration -similar electron carriers and transport mechanism as mitochondria -protons transported to periplasmic space rather than inner mitochondrial membrane -can use one carbon molecules instead of glucose (slide 48)

Question 35

describe the ETC of E coli

Answer 35

slide 49

Question 36

what is Oxidative Phosphorylation

Answer 36

Process by which ATP is synthesized as the result of electron transport driven by the oxidation of a chemical energy source (organic or inorganic)

Question 37

describe Chemiosmotic Hypothesis

Answer 37

slide 53

Question 38

describe ATP synthase (2)

Answer 38

-enzyme that uses PMF down gradient to catalyze ATP synthesis -functions like rotary engine with conformational changes (slide 56)

Question 39

The theoretical maximum total yield of ATP during aerobic respiration is ______

Answer 39

- 38 | - the actual number closer to 30 than 38

Question 40

The theoretical maximum total yield of ATP during aerobic respiration is____ in eukaryotes and _____ in prokaryotes

Answer 40

36 in a eukaryote 38 in a prokaryote **Actual yield in each is much lower About 30 in eukaryotes (proton leakage) and 16-28 in prokaryotes (see next slide)

Question 41

what are factors affecting ATP yield? (4)

Answer 41

1. ) Bacterial ETCs are shorter and have lower P/O ratios 2. ) ATP production may vary with environmental conditions 3. ) PMF in bacteria and archaea is used for other purposes than ATP production (flagella rotation) 4. ) Precursor metabolite may be used for biosynthesis

Question 42

slide 62-63

Answer 42

read over and understand

Question 43

describe anaerobic respiration

Answer 43

- Uses electron carriers other than O2 | - Generally yields less energy because E0 of electron acceptor is less positive than E0 of O2

Question 44

describe Nitrate Reduction and Denitrification

Answer 44

slides 66-68

Question 45

slides 69-71

Answer 45

idek

Question 46

describe Sulfate and Sulfur Reduction

Answer 46

72-75

Question 47

__________ use ____ as a final electron acceptor and reduce it to ________ in a series of reactions

Answer 47

Methanogens; CO2; CH4 (methane) * *Source of electrons is organic compound or inorganic compound * *slide 77

Question 48

describe fermentation

Answer 48

slides 78-81