MICROBIAL METABOLISM CH 10

Question 1

Metabolism

Answer 1

A broad term relating to the reactions and chemical workings of a cell (catabolic and anabolic reactions)

Question 2

Catabolic

Answer 2

Breaking molecules down; releases energy
(cats break things down)
(remember that breaking down releases energy because when ATP is broken down it releases energy)

Question 3

Anabolic

Answer 3

Building molecules up; requires energy

Question 4

This group of macromolecules usually end in -ase

Answer 4

Enzymes

Question 5

What is the function of enzymes and how do they work in reactions?

Answer 5

They speed up reactions lowering the activation energy (the energy required for the reaction to take place)

Question 6

Catalyst

Answer 6

An enzyme that speeds up reactions without changing the reaction

Question 7

Can enzymes be used in disease?

Answer 7

Pathogens can secrete enzymes to modify host cells (break things down)

Question 8

How do enzymes work?

Answer 8

Enzymes take substrates (reactant) and it binds to the active site where it modifies the substrate to create a product

This could be taking multiple substrates and putting them together to make one product (anabolism)
OR
taking a single substrate and breaking it down to form multiple products (catabolism)

Question 9

Oxidation vs Reduction; what is the broad term used to describe these reactions

Answer 9

REDOX REACTIONS
Oxidation is losing electrons
Reduction is gaining electrons
(OIL RIG)

Question 10

What enzyme do redox reactions use? How does it work?

Answer 10

Oxidoreductase works by transferring electrons from one molecule to another

Question 11

T/F: Oxidation is the gain of electrons

Answer 11

False;
Oxidation is losing electrons

Question 12

Metabolic pathways require _____ to catalyze each step

Answer 12

Enzymes

Question 13

The following are examples of:
NAD > NADH
FAD > FADH2
NADP > NADPH

Answer 13

Reduction reactions

Question 14

Aerobic vs Anaerobic Metabolism

Answer 14

Aerobic Metabolism - Oxygen is the final electron acceptor (forms water)
Anaerobic Metabolism - Final electron acceptor is something other than ozygen; (NO3-, SO42-, CO32-)

Question 15

How does energy move?

Answer 15

With the flow of electrons;
the more electrons a molecule has the more energy it has

Question 16

Describe the metabolic pathway of facultative anaerobes

Answer 16

When they have access to oxygen they carry out aerobic respiration

When they dont have access to oxygen they carry out fermentation

Question 17

If an organism is an obligate anaerobe, what metabolic pathway does it use?

Answer 17

Anaerobic Respiration

Question 18

What are one of the three molecules that are the final electron acceptor in anaerobic fermentation

Answer 18

Question 19

Describe Glycolysis; What are the products (net gain)

Answer 19

Glycolysis is the process by which glucose is broken down to form:
2 pyruvate
2 molecules of ATP
2 NADH

Question 20

How many times does glucose go through the krebs cycle?

Answer 20

Two times; once per each pyruvate

Question 21

Where is most of the ATP made in aerobic and anaerobic respiration

Answer 21

Electron Transport System

Question 22

Describe the Krebs Cycle; What are the products per molecule of glucose (net gain)

Answer 22

Pyruvate is converted into Acetyl CoA before enterring the Krebs Cycle and goes through twice (once per each pyruvate) to form:
2 ATP
2 FADH2
6 NADH

Question 23

Where does glycolysis take place in eukaryotic cells? Prokaryotic Cells?

Answer 23

Both in the cytosol

Question 24

Where does the krebs cycle and electron transport system take place in eukaryotic cells? Prokaryotic Cells?

Answer 24

Eukayote: Mitochondrial Membrane
Prokaryote: Cytoplasmic/ Cell Membrane

Question 25

Describe the electron transport system; What are the products (net gain)

Answer 25

NADH and FADH2 electrons (hydrogens) are tarnsferred to the proteins (enzymes) in the mitochondiral or cell membrane + are oxidized.

The electrons from the hydrogens are kept in the enzyme and the elctronless hydrogen atoms are pumped outside of the cell.

Electrons are transferred from enzyme to enzyme where the final electron is transferred to final electron acceptor (in aerobic respiration the final electron acceptor is oxygen and combines to form water)

The hydrogens move with their concentration gradient through the enzyme ATP Synthase where it phosphorylates 34 ATP

Question 26

What is the ATP yield of aerobic and anaerobic respiration?

Answer 26

Aerobic Respiration: 38 ATP
Anaerobic Respiration 2-36 ATP

Question 27

What is the ATP yield of fermentation?

Answer 27

2 ATP (just glycolysis)

Question 28

T/F: All metabolic pathways discussed in class start with glycolysis

Answer 28

True

Question 29

Which of the following processes require oxygen:
Glycolysis
Krebs Cycle
Electron Transport System

Answer 29

None of them require oxygen, thats why anaerobic molecules are able to undergo this entire process.

In aerobic respiration the only step that requires oxygen is the ETS

Question 30

What happens in alcohol fermentation

Answer 30

After pyruvate is made we remove two molecules of CO2 to create acetyldehyde; the two hydrogen from NADH are added to acetyldehyde to create ethanol