Metabolism Test

Question 1

Redox Reactions

Answer 1

Oxidation -> lose electrons
Reduction -> gain electrons
- occur together
OIL RIG

Question 2

What does Anaerobic mean? What is an example?

Answer 2

Can’t use O2
-yeast which is why it undergoes fermentation

Question 3

What does Facultative Anaerobic mean? What is an example of this?

Answer 3

• can use O2 or fermentation
• muscle cells

Question 4

What is the Endosymbionic Hypothesis? What evidence supports this hypothesis?

Answer 4

The endosymbionis hypothesis is that mitochondria was once a bacteria. A larger cell engulfed it -> Mitochondria got protection and the cell got an energy source. The evidence to support this hypothesis is that mitochondria are the same size as bacteria, they have a double membrane, and they have circular DNA.

Question 5

What is phosphorylation?

Answer 5

Phosphorylation is the transfer of a phosphate group to another molecule.

Question 6

What is Decarboxylation? In what part of metabolism is there a lot of decarboxylation reactions?

Answer 6

Decarboxylation is the removal of CO2 from a molecule. There are many decarboxylation reactions in the CAC.

Question 7

What is CoA and what is it’s function?

Answer 7

CoA is an enzyme that helps to stabilize molecules. CoA brings acetate to the CAC while also stabilizing it.

Question 8

What is Chemiosmosis? What process of metabolism does it occur in?

Answer 8

Chemiosmosis is the process in which an ATP is synthesized using an electrochemical gradient and the ATP synthase enzyme. When the buildup of H+ floods into the cell they have energy which is used to form ATP. Chemisosmosis produces ATP in the ETC.

Question 9

What is proton motive force? How does it help in the production of ATP?

Answer 9

Proton motive force is the force that moves protons because of an electrochemical gradient of protons across a membrane. Proton motive force pushes H+ through the enzyme ATP synthase resulting in the production of ATP.

Question 10

What is SLP? Where in metabolism does SLP occur?

Answer 10

Substrate-level phosphorylation is the formation of ATP by direct transfer of a phosphate group from a substrate to ADP. SLP occurs twice in glycolysis and once in the CAC.

Question 11

What is isomerase? What reactions is it involved in?

Answer 11

Isomerase is an enzyme that is used to change molecules in to one of their isomers. Isomerase is involed in all reactions involvung isomers - they each have specific types of the enzyme isomerase.

Question 12

Where does the Oxidation of Pyruvate occur? What enzyme is involved?

Answer 12

The oxidation of pyruvate occurs in the matrix of the mitochondria.
The enzyme pyruvate decarboxylase is involved in this reaction.

Question 13

How many reactions are there in the CAC?

Answer 13

10 - the production of ATP is counted in the total reactions

Question 14

Which cells can undergo the CAC?

Answer 14

Only aerobic cells can undergo the CAC. The CAC requires oxygen to be carried out.

Question 15

Where do the NADH and FADH from glycolysis and CAC go?

Answer 15

The NADH and FADH from glycolysis and CAC go to the ETC to make ATP.

Question 16

What are the products of the CAC (including the linkage step) per glucose?

Answer 16

• 8 NADH
  -2 FADH
  -6 CO2
  -2 ATP

Question 17

What are the products of glycolysis?

Answer 17

• 2 H2O
  -2 pyruvates -> go to CAC
  -2 NADH
  -2ATP

Question 18

What is an obligate aerobe?

Answer 18

An obligate aerobe is an organism that cannot live without oxygen. Most eukaryotes are obligate aerobes.

Question 19

What is oxidative phosphorylation? Where is it used?

Answer 19

Oxidative phosphorylation is a process that forms ATP using energy transferred indirectly from a series of redox reactions. Oxidative phosphorylation is used to make ATP in the ETC.

Question 20

Where does pyruvate oxidation occur?

Answer 20

Pyruvate oxidation occurs in the matrix of the mitochondria

Question 21

Can cells undergo aerobic cellular respiration without mitochondria? If yes, explain.

Answer 21

Yes, some prokaryotes undergo aerobic cellular respiration without mitochondria. The process of glycolysis, pyruvate oxidiation and the CAC occur in the cytosol of the cell. The ETC occurs on internal membranes that are derived from the plasma membrane. They still possess the full complement of reactions.

Question 22

What is an obligate anaerobe? What do they use for final electron acceptors?

Answer 22

An obligate anaerobe is an organism that cannot survive in the presence of oxygen. Instead of oxygen they use inorganic substances such as NO2, S, and Fe+3 as final electron acceptors to obtain energy.

Question 23

True or False - Aerobic respiration made the evolution of large animals possible.

Answer 23

True - allowed them to meet their very high energy demands.

Question 24

True or False - CAC is considered to be the most fundamental metabolic pathway.

Answer 24

False - Glycolysis is considered to be the most fundamental metabolic pathway.

Question 25

Does glycolysis require O2?

Answer 25

No

Question 26

True or False- Glycolysis is only found in prokaryotes.

Answer 26

False - Glycolysis is found in both prokaryotes and eukaryotes

Question 27

How many reactions are there in glycolysis?

Answer 27

There are 10 reactions in glycolysis.

Question 28

How does pyruvate enter the mitochondria?

Answer 28

Large pores in the outer membrane allow pyruvate to diffuse through. A pyruvate-specific membrane carrier is required for it to cross the inner membrane.

Question 29

What do some organisms do when there is excess ATP in their cells?

Answer 29

They use the extra ATP to phosphorylate creatine. When phosphorylated, creatine becomes a high energy molecule called creatine phosphate ehich can be stored within the cell. When ATP demand jumps the cell is able to reverse the reaction to generate additional ATP rapidly.

Question 30

Why do cells use fermentation?

Answer 30

They use fermentation to regenerate NAD+ to keep glycolysis going

Question 31

True or False - Anaerobic organisms use the ETC?

Answer 31

False - anaerobic organisms use fermentation instead of ETC to regnerqate NAD+. Only go through glycolysis and fermentation - no CAC or ETC.

Question 32

What was the first eukaryote to have its entire genome sequenced?

Answer 32

Yeast because of its commercial value.

Question 33

What are mitochondria limited by when producing ATP?

Answer 33

Mitochondria are limited by the amount of available O2 - ETC can't carry out its process without O2 to act as final electron acceptor

Question 34

Where does fermentation occur?

Answer 34

Fermentation occurs in the cytoplasm.

Question 35

Where odes the lactate produced in humans go?

Answer 35

The lactate produced by our muscle cells is transported to our liver where it is oxidized back to pyruvate.

Question 36

What are the 2 jobs of the ETC?

Answer 36

a) Transport electrons to make H2O b) Pump H+ out to make ATP