Question 1

An anaerobic process does NOT require

Accepted Answer

Anaerobic processes occur without the presence of oxygen.

Question 2

Aerobic cellular respiration requires the use of

Accepted Answer

Aerobic cellular respiration requires the use of oxygen (O2) as the final electron acceptor in the electron transport chain.

Question 3

____ is NOT a product of the Kreb cycle.

Accepted Answer

Pyruvic acid is not a product of the Krebs cycle; it is a substrate that enters the cycle after being converted to acetyl-CoA.

Question 4

____ is NOT a stage of cellular respiration.

Accepted Answer

The Calvin cycle is part of photosynthesis, not cellular respiration.

Question 5

Oxygen is NOT necessary for

Accepted Answer

Anaerobic cellular respiration does not require oxygen; it uses other molecules as the final electron acceptor.

Question 6

A reaction that requires oxygen is called

Accepted Answer

A reaction that requires oxygen is called aerobic.

Question 7

The end product of glycolysis is

Accepted Answer

Glycolysis is a metabolic pathway that converts glucose into pyruvic acid, which is the end product of this process.

Question 8

Your cells most readily obtain energy from

Accepted Answer

Cells most readily obtain energy from ATP (Adenosine Triphosphate), which is the primary energy carrier in all living organisms. It provides energy for various cellular processes by releasing a phosphate group, thus transforming into ADP (Adenosine Diphosphate).

Question 9

The total (gross) number of ATPs produced from glycolysis is estimated to be

Accepted Answer

Glycolysis directly produces a total of 4 ATPs on a gross basis, but because 2 ATPs are used up in the early steps of glycolysis, the net gain is often considered to be 2 ATPs. However, the question specifically asks for the gross number, which is 4.

Question 10

During glycolysis, a six-carbon sugar is converted to

Accepted Answer

During glycolysis, a six-carbon sugar (glucose) is broken down into two three-carbon molecules of pyruvic acid.

Question 11

In glycolysis, the net profit of ATP from one six-carbon sugar is

Accepted Answer

Glycolysis results in a net gain of two ATP molecules per molecule of glucose.

Question 12

Glucose + NAD⁺ + ADP + P $\rightarrow$ NADH + Pyruvic Acid + ATP. This formula represents

Accepted Answer

This formula represents glycolysis, a metabolic pathway that converts glucose into pyruvic acid, producing ATP and NADH in the process, which occurs in the cytoplasm of cells.

Question 13

Conversion of a six-carbon carbohydrate to two pyruvic acid molecules with accompanying reactions that release ATP and hydrogen atoms is called

Accepted Answer

Glycolysis is the metabolic pathway that converts glucose (a six-carbon carbohydrate) into two molecules of pyruvic acid, producing ATP and NADH (which carries hydrogen atoms) in the process. This occurs in the cytoplasm of cells and does not require oxygen.

Question 14

Chemosynthesis is

Accepted Answer

Chemosynthesis is a process by which some autotrophs (organisms that produce their own food) use chemical energy to produce organic matter from inorganic substances. Unlike photosynthesis, which uses sunlight for energy, chemosynthesis relies on chemical reactions, often involving sulfur or methane. This process is found in some bacteria and archaea, typically in environments without sunlight, such as deep-sea hydrothermal vents.

Question 15

A form of metabolism used by prokaryotic organisms is

Accepted Answer

All of these forms of metabolism—chemosynthesis, photosynthesis, and anaerobic respiration—are utilized by various prokaryotic organisms to produce energy, demonstrating the metabolic diversity within this group.

Question 16

The Krebs cycle requires

Accepted Answer

The Krebs cycle, also known as the citric acid cycle, requires all of these components to function. A four-carbon acid (oxaloacetate) combines with an acetyl group (2C) from acetyl-CoA, where coenzyme A (CoA) is a carrier of the acetyl group, to start the cycle.

Question 17

The Krebs cycle produces

Accepted Answer

The Krebs cycle, also known as the citric acid cycle, produces carbon dioxide as one of its byproducts when acetyl-CoA is oxidized to produce energy.

Question 18

Acetyl can be produced directly from

Accepted Answer

Acetyl can be produced directly from pyruvic acid through a process called pyruvate decarboxylation, where pyruvate is converted into acetyl-CoA. This reaction is a key step in cellular respiration, linking glycolysis to the citric acid cycle.

Question 19

Acetyl is used during

Accepted Answer

Acetyl groups are primarily used during the Krebs cycle, where acetyl-CoA enters the cycle and is metabolized to produce energy in the form of ATP, NADH, and FADH2.

Question 20

Hydrogens are combined with oxygen at the completion of

Accepted Answer

During the electron transport system, hydrogens (protons and electrons) are combined with oxygen to form water. This is the final step in the process of cellular respiration where the oxygen acts as the final electron acceptor.

Quiz 6: Biochemical Pathways: Cellular Respiration