Chapter 6

Question 1

Why do microbes need energy?
(carbon and energy sources diagram too)

Answer 1

Growth and maintaining life.

Question 2

What are the two types of energy currencies in biology?

Answer 2

ATP and Reducing Power: NAD(P)H.

Question 3

Feeder pathways:

Answer 3

Assimilate carbon in the
central pathways. Any (minor) metabolic pathway that supplies metabolites to another (major) metabolic pathway

Question 4

Heterotrophic Fueling:

Answer 4

Energy and carbon sources often are the same, so they have the same pathway.

Question 5

Autotrophic Fueling:

Answer 5

Energy and carbon sources are different, so they have different pathways.

Question 6

What are the central pathways for heterotrophic and autotrophic fueling?

Answer 6

Glycolysis, Citric Acid Cycle, Pentose phosphate cycle

Question 7

ATP synthesis Mechanisms (2 mechanisms with more info about them).

Answer 7

Substrate Level Phosphorylation (fermentation, glycolysis, TCA)

Transmembrane Ion Gradients (Respiration: Oxidative Phosphorylation and Photosynthesis: Photophosphorylation)

Question 8

What are the 2 methods of phosphorylation ATP uses to generate ADP?

Answer 8

Substrate Level Phosphorylation and Transmembrane Ion Gradients.

Question 9

Four types of macromolecules

Answer 9

Proteins, nucleic acids, lipids, polysaccharides.

Question 10

Four building blocks

Answer 10

Amino acids, nucleotides, fatty acids, sugars.

Question 11

Chemoheterotrophs

Answer 11

Integrate carbon and energy metabolism. Organic molecules serve as both the carbon and energy source.

Microbes that use organic chemical substances as sources of energy and organic compounds as the main source of carbon

Question 12

Chemoautotrophs

Answer 12

Fix carbon dioxide and make precursor metabolites – Uses a lot of energy or Reducing power. Aerobic or anaerobic.

Synthesize their own organic molecules from the fixation of carbon dioxide.

Question 13

Photoautotrophs

Answer 13

Use CO2 as carbon source.

Oxygenic: Cyanobacteria, algae, green plants
Anoxygenic: Green bacteria (sulfur), Purple bacteria (sulfur)

Question 14

Photoheterotrophs

Answer 14

Use organic compounds as carbon source.
Green nonsulfur bacteria and purple nonsulfur bacteria.

Question 15

What are the two pathways within auxiliary pathways?

Answer 15

Entner-Duodoroff pathway and Fermentation pathway.

Question 16

Fermentation
- what does it produce and what does it use to produce it?
- anaerobic or aerobic?
- where does it occur?
- what does it achieve?

Answer 16

Some microbes use only this for fueling.
Substrate level phosphorylation to produce ATP. Produces Reducing Power.
No oxygen required (anaerobic).
Takes place in cytoplasm.
Achieves “Redox Balance”
Auxiliary fueling pathways

Question 17

What problem does fermentation leave?

Answer 17

How to recycle extra NADH back to NAD+.

Question 18

What are the steps of aerobic respiration?

Answer 18

Glycolysis, Krebs Cycle, Electron transport chain and chemiosmosis.

Question 19

What are the terminal electron acceptors for aerobic and anaerobic?

Answer 19

Aerobic: oxygen
Anaerobic: inorganic or organic

Question 20

What are possible electron acceptors for anaerobic respiration?

Answer 20

Question 21

Which type of microbe can undergo fermentation?

Answer 21

Chemoheterotrophs, organic molecules serve as both carbon and energy sources.

Question 22

Oxygenic (photosynthesis) :

Answer 22

Water for electrons, O2 formed.

Question 23

Anoxygenic (photosynthesis):

Answer 23

Water not used, no O2 formed.

Question 24

Photoautotrophs use ____

Answer 24

CO2 as carbon source

oxygenic: cyanobacteria, algae, green plants

anoygenic: green bacteria and purple bacteria (sulfur)

Question 25

Photoheterotrophs use ________

Answer 25

Organic compounds as carbon source

*green nonsulfur bacteria, purple nonsulfur bacteria

Question 26

How many precursor metabolites are made by fueling?

Answer 26

13

Question 27

Photosynthesis

Answer 27

CO2 fixation is very demanding, so energy source needed. Light provides energy source for protom pumping.

Question 28

Chlorophylls:

Answer 28

Harness energy in light to push an electron to a higher energy level (photophosphorylation)