Lactic acid fermentation can be modeled by which equation?(1 point)

Question

Responses

Pyruvic acid + NAD+ → Lactic acid + NADH
Pyruvic acid + NAD+ → Lactic acid + NADH

Pyruvic acid + NADH → Lactic acid + NAD+
Pyruvic acid + NADH → Lactic acid + NAD+

Lactic acid + NADH → Pyruvic acid + NAD+
Lactic acid + NADH → Pyruvic acid + NAD+

Lactic acid + NADH → Pyruvic acid NADH

Answer 1

The correct equation that models lactic acid fermentation is:

Pyruvic acid + NADH → Lactic acid + NAD+

This reaction involves the conversion of pyruvic acid into lactic acid, with NADH being oxidized back to NAD+, which is essential for the continuation of glycolysis under anaerobic conditions.

Answer 2

In the Krebs cycle, how is citric acid formed?(1 point)
Responses

Pyruvic acid molecules are broken down by an acetyl group.
Pyruvic acid molecules are broken down by an acetyl group.

Enzymes combine hydrogen ions, oxygen, and electrons.
Enzymes combine hydrogen ions, oxygen, and electrons.

Carbon dioxide bonds with a chain of coenzyme A.
Carbon dioxide bonds with a chain of coenzyme A.

Acetyl-CoA joins with a large molecule called oxaloacetic acid.

Answer 3

The correct response for how citric acid is formed in the Krebs cycle is:

Acetyl-CoA joins with a large molecule called oxaloacetic acid.

This reaction results in the formation of citric acid (also known as citrate) and is the first step of the Krebs cycle (citric acid cycle).

Answer 4

Which molecule provides the activation energy that starts glycolysis? (Not which molecule is broken down during glycolysis)(1 point)
Responses

ATP
ATP

water
water

carbon dioxide
carbon dioxide

sugar

Answer 5

The molecule that provides the activation energy that starts glycolysis is:

ATP

During the initial steps of glycolysis, ATP is used to phosphorylate glucose and its intermediates, which helps to facilitate the process of breaking down glucose for energy.

Answer 6

During which phase of cellular respiration is carbon dioxide released?(1 point)
Responses

electron transport chain
electron transport chain

digestion
digestion

Krebs cycle
Krebs cycle

glycolysis

Answer 7

Carbon dioxide is released during the:

Krebs cycle

In the Krebs cycle (also known as the citric acid cycle), carbon dioxide is produced as a byproduct when acetyl-CoA is oxidized.

Answer 8

How many glucose molecules can undergo cellular respiration when 13 O2 molecules are available to react?(1 point)
Responses

0
0

3
3

2
2

1

Answer 9

To calculate how many glucose molecules can undergo cellular respiration with 13 O2 molecules, it's important to consider the stoichiometry of cellular respiration.

The overall equation for cellular respiration can be summarized as:

\[ \text{C}6\text{H}{12}\text{O}_6 + 6 \text{O}_2 \rightarrow 6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{energy} \]

This equation indicates that 1 glucose molecule requires 6 O2 molecules for complete oxidation.

Given 13 O2 molecules:

1. Calculate how many glucose molecules can be supported by 13 O2:
   • For each glucose, 6 O2 are needed.
   • Therefore, the number of glucose molecules that can react = Total O2 available / O2 required per glucose = 13 / 6 = 2.166...

Since the number of complete glucose molecules that can undergo respiration must be a whole number, you can fully oxidize 2 glucose molecules with 12 O2 (which is \(2 \times 6\) O2), and there will be 1 O2 molecule remaining.

Thus, the answer is:

2

Answer 10

How many O2 molecules are required for two glucose molecules to undergo cellular respiration?(1 point)
Responses

18
18

2
2

6
6

12

Answer 11

For one glucose molecule to undergo cellular respiration, 6 O2 molecules are required.

Therefore, for two glucose molecules:

\[ 2 \text{ glucose} \times 6 \text{ O2 per glucose} = 12 \text{ O2} \]

So, the answer is:

12