Question 1(multiple choice worth 2 points)
where does the krebs cycle occur?

cytoplasm
mitochondrion
cell membrane
nucleus

question 2(multiple choice worth 2 points)
what stage of cellular respiration produces the most atp?

electron transport chain
glycolysis
krebs cycle
fermentation

question 3(multiple choice worth 2 points)
cellular respiration and fermentation

begin with the breakdown of glucose in glycolysis
produce the same number of atp molecules
only occur in animal cells
require oxygen molecules as a reactant

question 4(multiple choice worth 2 points)
during the process of cellular respiration, energy stored in glucose molecules is used to form

oxygen molecules
nad+
atp
carbohydrates

question 5(multiple choice worth 2 points)
when pyruvate molecules enter the mitochondrion during cellular respiration, they react to form

ethyl alcohol and atp
acetyl-coa and carbon dioxide
glucose and carbon dioxide
lactic acid and nad+

question 6(multiple choice worth 2 points)
during fermentation, the conversion of pyruvate into lactic acid requires

nadh
carbon dioxide
atp
oxygen gas

question 7(multiple choice worth 2 points)
alcoholic

forms fewer atp molecules than cellular respiration
uses oxygen and atp molecules as reactants
occurs in the muscle cells of animals and humans
gives off carbon dioxide and nadh as products

question 8(multiple choice worth 2 points)
which of the following is a necessary reactant for cellular respiration to occur?

carbon dioxide
nitrogen
oxygen
water

question 9(multiple choice worth 2 points)
what stage of cellular respiration is anaerobic?

glycolysis
calvin cycle
electron transport chain
krebs cycle

question 10(multiple choice worth 2 points)
what is produced during the krebs cycle?

co2, atp, nadh, and fadh2
pyruvate, co2, and atp
atp, fadh2, and h2o
h2o, adp, and nadh

1. The right answer is Mitochondrion  

Mitochondria not only play a fundamental role in the oxidative catabolism leading to the production of a usable form of energy, ATP, but they also play a determining role in apoptosis, thermogenesis, calcium homeostasis, and many anabolic pathways such as the synthesis of heme, iron-sulfur proteins, nucleotides or even steroids.

2. The right answer is Electron transport chain  

An electron transport chain is a series of enzymes and coenzymes that globally perform two actions simultaneously: it transfers electrons from electron donors to electron acceptors during successive redox reactions, and ensures the pumping of protons or other cations through a biological membrane. This has the effect of generating a proton concentration gradient across this membrane, resulting in an electrochemical gradient whose potential energy can be recovered by ATP synthases to phosphorylate ADP molecules into ATP. The final acceptor of electrons is usually oxygen in aerobic organisms, but may be another oxidant in some species.

3. The right answer is begin with the breakdown of glucose in glycolysis.

Glycolysis is the first step of carbohydrate (especially glucose) catabolism, it is carried out in the cytosol by soluble enzymes and anaerobically (without oxygen supply). Its function is the synthesis of molecules rich in energy, as well as the formation of pyruvate which will have several destinies. The glycolysis is composed of 10 large steps, involving 10 enzymes to obtain at the end of the pyruvate and formation of molecules rich in energy (2 ATP and 2 NADH, H + as balance).

4. The right answer is ATP  

ATP is an abbreviation for adenosine triphosphate, it represents a molecule rich in chemical energy, universally used by cells to store energy. It is produced during photorespiration and cellular respiration, and is consumed by many enzymes in the catalysis of many chemical processes. Its molecular formula is C10H16N5O13P3.

5. The right answer is acetyl-CoA and carbon dioxide  

In aerobic, pyruvate enters the mitochondria where it undergoes decarboxylation and combined oxidation of acetyl-CoA. This irreversible reaction is catalyzed by the multienzyme complex of pyruvate dehydrogenase composed of three enzymes (pyruvate dehydrogenase, dihydrolipoamide transacetylase and dihydrolipoamide dehydrogenase) and five coenzymes (thiamine pyrophosphate, lipoic acid, CoASH, FAD and NAD +).

6. The right answer is NADH  

Fermentation produces few energy (ATP) even without the presence of oxygen, but with a lower yield. It is used by a very large number of organisms, from bacteria to humans.

Some organisms exclusively use this metabolic pathway, others alternate between fermentation and respiration, depending on conditions (presence of O2, glucose concentration, etc.).

Fermentation is also used in many industrial processes, such as the production of cheese, alcohol, biofuel, etc.

7. The right answer is forms fewer ATP molecules than cellular respiration  

It is easy to see that cellular respiration is much more effective than fermentation. There are 36 ATP molecules created by glucose molecules during respiration against 2 ATP molecules during fermentation. Figure 3 provides a summary of both metabolisms.

8. The right answer is Oxygen.

Oxygen is a vital element for the living because it is at the center of the breathing of many living beings. It also participates in combustion processes. Oxygen is the most abundant element in the earth's crust and one-fifth of the Earth's atmosphere is composed of oxygen in the form of diatomic gas, O2, but also, in trace amounts, in the form of ozone. O3.

9. The right answer is Glycolysis  

A glycolysis or Embden-Meyerhof-Parnas pathway is a metabolic pathway of glucose assimilation and energy production. It takes place in the hyaloplasm (or cytosol) of the cell. As the name implies, it requires glucose and produces pyruvate. The latter can either enter the Krebs cycle, which takes place in the mitochondria of eukaryotes or the cytoplasm of aerobic bacteria, or be metabolized by fermentation to anaerobiosis, to produce, for example, lactate or ethanol.

10. The right answer is CO2, ATP, NADH, and FADH2  

The Krebs cycle, also known as the citric acid cycle by anglicism, is a metabolic pathway present in all aerobic organisms whose primary function is to oxidize acetyl groups, resulting in particular from the breakdown of carbohydrates, fats and proteins, to recover energy in the form of eight electrons with high transfer potential and a molecule of GTP or ATP; the high transfer potential electrons recovered from NADH and ubiquinol (CoQ10H2, or reduced coenzyme Q10) can then circulate through the respiratory chain to in turn allow the formation of additional ATP molecules by oxidative phosphorylation .

answer: the answer is b