Problem Set #6- Cellular Respiration

Question 1

For every molecule of glucose that goes into glycolysis, what comes out*? Select all 4 correct answers for credit.

*By “what comes out”, I am referring to the end of the entire cycle (after the full 10 steps, not intermediates).

Answer 1

ATP
NADH
H2O
PYRUVATE

The products of glycolysis are:

2 NADH
2 H+ (proton, hydrogen ion)
2 ATP
2 H2O
2 Pyruvate

Question 2

The bacterium E. coli is a facultative anaerobe, meaning that depending on its environmental surroundings it can grow and divide under either aerobic or anaerobic conditions. The rate of cell division is limited only by the cell’s ability to generate the energy required to synthesize and duplicate necessary macromolecules. Using the following growth curves, which statement is correct?

Answer 2

The orange curve (curve closest to the y-axis) is the results of E. coli growing aerobically and the blue cure (curve farthest from the y-axis) is from cells grown anaerobically.

Anaerobic vs aerobic DOES have an affect on growth RATE. And, here, aerobic gets them to the max pop size fastest.

Question 3

NADH is the ______ form of NAD+ while NAD+ is the _____ form of NADH.

Answer 3

reduced; oxidized

NAD+ the oxidized form (fewest electrons!)
–Becomes reduced to form NADH
–Accepts e- during redox rxns

NADH the reduced form (most electrons!)
–Becomes oxidized to form NAD+
–Donates e- during redox rxns

Question 4

In glycolysis, for each molecule of glucose oxidize to pyruvate, ___________________

Answer 4

four molecules of ATP are produced, and two molecules of ATP are used.

In total, 4 ATP are produced…however, it takes 2 ATP to make those 4 ATP so the net yield is 2 ATP molecules.

Question 5

Match the function with the structure’s letter. Some letters may not be used while others may be used more than once.

Answer 5

Site of pyruvate oxidation-Matrix
Site of oxidative phosphorylation-Inner Membrane
Site of the Citric Acid Cycle-Matrix
Increase capacity of mitohondria to synthesize ATP-Cristae
Accumulates a bunch of protons (H+) during ETC-Intermembrane Space

Question 6

Fifteen glucose molecules have been oxidized under aerobic conditions. How many CO2 molecules were produced? Enter a number below.

Enter a whole, numerical number

Answer 6

90 (with margin: 0)

Each molecule of glucose oxidizes 6 CO2 molecule. 15*6 = 90.

Question 7

What molecule is an output of pyruvate oxidation and an input for the citric acid cycle?

Answer 7

Acetyl CoA

Question 8

What is the effect of decreased levels of H+ ions in the intermembrane space of the mitochondria?

Answer 8

Decreased ATP production.

The ETC in oxphos increases the levels of hydrogen protons (H+) in the intermembrane space. Therefore, chemiosmosis is increased with more H+ available. Increased ATP production is the result of the flow of hydrogen protons from the intermembrane into the mitochondrial matrix.

Question 9

During cellular respiration, what happens to the 6 oxygen molecules (O2)?

Answer 9

All 6 are reduced to H2O.

During cellular respiration (thru a series of enzymatic reactions) glucose is oxidized and produces CO2 and Oxygen is reduced and produces H2O.

Question 10

Chlamydomonas is a unicellular eukaryote that you worked with in lab. One of your “Chlamy” had a busy morning and underwent multiple rounds of glycolysis, producing 64 total molecules of pyruvate. How many molecules of ATP did this Chlamy gross during the investment payoff phase?

Answer 10

128

If Chlamy produced 64 molecules of pyruvate it underwent 32 rounds of glycolysis, right?

32 rounds of glycolysis would GROSS 128 molecules of ATP, but NET 64.

Question 11

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Answer 11

It does not require oxygen.
Nearly every organism does it.
It does not involve organelles or specialized structures.

It does produce much less ATP than does oxidative phosphorylation but that is not why it evolved first.

Question 12

The role of NADH in cellular respiration is to:

Answer 12

donate electrons during redox reactions and become oxidized to form NAD+

NADH the reduced form (most electrons!)

–Becomes oxidized to form NAD+
–Donates e- during redox rxns

Question 13

Most CO2 from cellular respiration is released during

Answer 13

the citric acid cycle.

Harvests the remaining extractable energy from the glucose molecule and releases the remaining 4 CO2

Question 14

Which of the following organisms perform aerobic cellular respiration?

Answer 14

All of the above

All of these organisms do aerobic respiration.

Question 15

Which molecule is a common output of glycolysis, pyruvate oxidation, AND the citric acid cycle?

Answer 15

NADH

Question 16

ou go to your favorite chicken place and get tenders with a side of sweet BBQ sauce. Which components of your meal provides the most energy (in the form of carbohydrates) to help power cellular respiration?

Answer 16

The breading on the tender.
The BBQ sauce

Which two components of this meal have the most carbs/sugar in them? Breading and BBQ sauce.

Meat = protein
Oil = lipids
Water = nothing
Parsley = micro-nutrients (sodium, potassium, etc.)

Question 17

Fermentation relies on which of the following stage(s) of cellular respiration?

Answer 17

Glycolysis

Glycolysis occurs under anaerobic conditions (lack of oxygen), like fermentation. Krebs’ cycle and electron transport chain occurs under aerobic conditions (requires oxygen).

Question 18

If prokaryotes do not have mitochondria, then where are the enzymes for cellular respiration located?

Answer 18

In the plasma membrane

Prokaryotes absolutely DO respiration; however Prokaryotes do NOT have mitochondria or a nuclear membrane.

Ribosomes are were proteins are made (and prokaryotes DO have them).

Prokaryotes DO have cytoskeletons, but this is not where the machinery for respiration is. That machinery is in their membranes.

Question 19

Where does cellular respiration occur in plants?

Answer 19

In their mitochondria.

Question 20

The final electron acceptor for cellular respiration is:

Answer 20

Oxygen

Remember, oxygen is very electronegative meaning it’s going to be greedy about acquiring electrons. This high affinity for electrons makes oxygen a great acceptor for low-energy electrons. With the electrons, hydrogen is added to oxygen forming water as the final product.

Question 21

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + i to ATP?

Answer 21

Energy released from movement of protons through ATP synthase, down their electrochemical gradient

Question 22

What is produced when yeasts undergo fermentation?

Answer 22

Ethanol & CO2

Yeasts (as well as other organisms) undergo alcohol fermentation and produce EtOH and CO2 in the process.

Question 23

Lactic Acid Fermentation
Why is CO2 produced as a product in alcoholic fermentation, but not in lactic acid fermentation?

Answer 23

There is no carbon remaining to form the byproduct CO2 in lactic acid fermentation

In alcoholic fermentation, pyruvate (3-C) is converted in to ethanol (2-C). The byproduct is CO2.

In lactic acid fermentation, pyruvate (3-C) is converted in to lactate (3-C). There is no carbon remaining to form the byproduct CO2 in this reaction. Different organisms, different methods for recycling the electron carrier (NAD)

Question 24

ATP is an important biological molecule that transports chemical energy within cells and powers many biochemical reactions. Which of the following correctly describes the structure of ATP and how it provides energy?

Answer 24

ATP contains a 5-carbon sugar, three phosphate groups, and an adenine base. Energy is released when the bond between the second phosphate group and third phosphate group is broken.

ATP is made of a 5-carbon sugar (ribose), three phosphate groups, and an adenine base. The phosphate groups are negatively charged, making the bonds between them unstable. When the bond between the second and third phosphate group breaks, energy is released.

Question 25

In the image, what major process is occurring during #3?

Answer 25

The release of a bunch of CO2.

1. Glycolysis
2. Pyruvate Oxidation.
3. Citric Acid Cycle
4. Oxidative Phosphorylation