Biology Chapter 9 Assessment

Questions and Answers

The energy available in food is used to make an energy-rich compound called?

ATP

First step in releasing the energy of glucose in the cell is known as ____________________.

glycolysis

The process that releases energy from food in the presence of oxygen is _____________________.

cellular respiration

The net gain of energy from glycolysis is ___________.

2 ATP molecules Signup and view all the answers

Because fermentation takes place in the absence of oxygen, it is said to be _______________.

anaerobic Signup and view all the answers

The Krebs cycle takes place within the __________.

mitochondrion Signup and view all the answers

The electron transport chain uses the high-energy electrons from the Krebs cycle to __________.

convert ADP to ATP Signup and view all the answers

A total of 36 molecules of ATP are produced from 1 molecule of glucose as a result of _____________________.

cellular respiration Signup and view all the answers

During heavy exercise, the buildup of lactic acid in muscle cells results in ___________.

oxygen debt Signup and view all the answers

What is a calorie?

The amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius Signup and view all the answers

How do cells use a high-calorie molecule such as glucose?

Cells break down the glucose releasing the stored energy a small amount at a time. Signup and view all the answers

How is glucose changed during glycolysis?

It gets broken into two 3-carbon molecules called pyruvic acid. Signup and view all the answers

What products are produced as a result of glycolysis?

Two 3-carbon molecules of pyruvic acid are produced. Signup and view all the answers

What is the chemical equation for cellular respiration?

6 O2 + C6H12O6 --> 6 CO2 + 6 H2O + Energy Signup and view all the answers

Name the compounds of the chemical equation for cellular respiration.

Oxygen, Glucose --> Carbon Dioxide + Water + Energy Signup and view all the answers

How is NAD+ involved in the products of glycolysis?

It picks up high-energy electrons. Signup and view all the answers

What happens to a cell's NAD+ when large numbers of high-energy electrons are produced in a short time?

The high-energy electrons quickly fill all of the cell's available NAD+. Signup and view all the answers

Which two compounds react during fermentation? Which of these passes high-energy electrons to the other?

Pyruvic acid and NADH Signup and view all the answers

Write equations to show how lactic acid (1) fermentation compares with alcoholic fermentation (2).

(1) glucose ---> lactic acid; (2) glucose ---> alcohol + CO2; Both have glucose as the reactant. Signup and view all the answers

How are fermentation and cellular respiration similar? What is the main difference between their starting compounds?

Similarities: both processes break down glucose and release the energy stored in the molecule. Difference: Cellular respiration requires oxygen, while fermentation occurs WITHOUT oxygen. Signup and view all the answers

What happens during the Krebs cycle?

Pyruvic acid is broken down into carbon dioxide in a series of reactions that give off energy. Signup and view all the answers

What happens to the high-energy electrons generated during the Krebs cycle?

They are picked up by a series of electron carriers, and the energy is used to convert ADP into ATP. Signup and view all the answers

How is ATP synthase involved in making energy available to the cell?

ATP synthase is a large protein through which hydrogen ions (H+) pass, converting ADP into high-energy ATP. Signup and view all the answers

When runners race for about 20 minutes, how do their bodies obtain energy?

In the beginning of the race -- they get energy from ATP that is in their muscles and produced by lactic acid fermentation. After 20 minutes, bodies use cellular respiration to use stored carbohydrates to make ATP. Signup and view all the answers

Study Notes

Energy in Food

Food energy is converted into ATP, a key energy-rich compound utilized by cells.

Glycolysis

The initial process of glucose energy release occurs through glycolysis.
Glycolysis breaks glucose into two 3-carbon molecules called pyruvic acid.
The net gain from glycolysis is 2 ATP molecules.

Cellular Respiration

Cellular respiration is the process that extracts energy from food, requiring oxygen.
A total of 36 ATP molecules can be produced from one glucose molecule during cellular respiration.

Fermentation

Fermentation occurs in the absence of oxygen, classified as anaerobic.
During fermentation, high-energy electrons from NADH are passed to pyruvic acid.

Krebs Cycle

The Krebs cycle occurs within the mitochondrion and processes pyruvic acid, releasing carbon dioxide and energy.
High-energy electrons from the Krebs cycle are utilized to convert ADP into ATP.

Electron Transport Chain

The electron transport chain harnesses high-energy electrons to create ATP.

Oxygen Debt

Heavy exercise leads to lactic acid buildup in muscle cells, resulting in oxygen debt.

Caloric Energy

A calorie is defined as the energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.
Cells break down glucose, releasing stored energy gradually.

Chemical Equations

The chemical equation for cellular respiration is 6O2 + C6H12O6 → 6CO2 + 6H2O + Energy, involving oxygen and glucose as reactants.

NAD+ and Electron Transfer

NAD+ plays a role in glycolysis by picking up high-energy electrons.
As high-energy electrons accumulate, cells may reach a saturation point for NAD+.

Comparison of Fermentation Types

Lactic acid fermentation: glucose → lactic acid.
Alcoholic fermentation: glucose → alcohol + CO2.
Both types begin with glucose as a reactant.

Similarities and Differences of Fermentation and Cellular Respiration

Both processes break down glucose to release energy and initiate with glycolysis.
Primary distinction: Cellular respiration requires oxygen, while fermentation does not.

ATP Synthase Function

ATP synthase facilitates energy production by allowing hydrogen ions to pass through, converting ADP into ATP.

Energy Use During Exercise

Initial energy in a race is derived from stored ATP and lactic acid fermentation.
After approximately 20 minutes, the body switches to cellular respiration for ATP production from stored carbohydrates.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of Chapter 9 in Biology with these flashcards. This quiz covers key concepts such as ATP, glycolysis, and cellular respiration. Ideal for students looking to reinforce their understanding of energy release in cells.