Biology Section 9-2: Krebs Cycle & Electron Transport

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the average number of ATP molecules produced as each pair of high-energy electrons moves down the electron transport chain?

3 (correct)

What role do high-energy electrons from NADH and FADH2 play in cellular respiration?

They directly produce ATP.

They provide energy to move glucose.

They create H+ concentration gradients. (correct)

They are converted to NAD+ and FAD.

What happens to the H+ ions in the intermembrane space during cellular respiration?

They combine with NADH.

They are reintroduced into glucose.

They contribute to an electrochemical gradient. (correct)

They dissipate into the cytoplasm.

Why does more ATP get generated from glucose in the presence of oxygen?

Oxygen allows complete oxidation of glucose. Signup and view all the answers

What is the final waste product of cellular respiration?

Carbon dioxide Signup and view all the answers

What is the role of ATP synthase in cellular respiration?

It uses energy from H+ ions to generate ATP. Signup and view all the answers

How does the body supply ATP for short-duration exercise, like sprinting?

Through anaerobic processes, such as lactic acid fermentation. Signup and view all the answers

What causes high-energy electrons to move down the electron transport chain?

The release of energy during oxidation. Signup and view all the answers

What happens to pyruvic acid during the Krebs cycle?

It is broken down to release carbon dioxide. Signup and view all the answers

Why is the Krebs cycle referred to as the citric acid cycle?

Citric acid is produced as the first compound. Signup and view all the answers

What do electrons form when they join NAD+ and FAD during the Krebs cycle?

NADH and FADH2 Signup and view all the answers

What is the primary role of the electron transport chain in cellular respiration?

To use high-energy electrons to create a gradient for ATP production. Signup and view all the answers

How does the location of the electron transport chain differ between eukaryotes and prokaryotes?

It is located within the mitochondria in eukaryotes and the cell membrane in prokaryotes. Signup and view all the answers

What is the final electron acceptor in the electron transport chain?

Oxygen Signup and view all the answers

Which compound is considered the only permanent compound in the Krebs cycle?

Oxaloacetate Signup and view all the answers

Study Notes

Section 9-2 The Krebs Cycle and Electron Transport

Key Concepts:
- What happens during the Krebs cycle?
- How are high-energy electrons used by the electron transport chain?

Introduction

At the end of glycolysis, much of the chemical energy in glucose is still unused.
The final stages of cellular respiration require oxygen.

The Krebs Cycle

In the presence of oxygen, pyruvic acid from glycolysis is used.
Pyruvic acid is processed during the Krebs cycle.
The Krebs cycle is also known as the citric acid cycle.
The Krebs cycle begins when pyruvic acid is broken down.
Each of the 3 carbon atoms in pyruvic acid is affected when it breaks down.
Carbon dioxide is produced in the breakdown of pyruvic acid.
Citric acid is produced during the cycle.
During the energy extraction part of the Krebs cycle, several CO2 molecules are released.
The energy tally from one molecule of pyruvic acid during the Krebs cycle is detailed.

Electron Transport

When electrons join NAD+ and FAD during the Krebs cycle, they form new compounds.
The 4-carbon compound produced in breaking down citric acid is the only permanent compound in the Krebs cycle.
The electron transport chain is a system for using high-energy electrons from the Krebs cycle.
The location of the electron transport chain differs in eukaryotes and prokaryotes.
The high-energy electrons are passed down the electron transport chain.
Hydrogen serves as the final electron acceptor.
The energy of high-energy electrons is used for generating ATP.
H+ ions move through channels in the membrane.
On average, a specific number of ATP molecules are produced for each pair of high-energy electrons that pass down the electron transport chain.

The Totals

A specific number of ATP molecules are formed during cellular respiration.
More ATP is generated from glucose in the presence of oxygen.
The energy from glucose that is not used to make ATP molecules goes elsewhere.
The final waste products of cellular respiration are identified.

Energy and Exercise

Three sources of ATP used by the human body at the beginning of a race are listed.
A rapid source of ATP for short races is identified.
The reason a sprinter has an oxygen debt after a race is explained.
How the body generates energy for longer races is outlined.
Aerobic exercise's benefits for weight control are discussed.

Comparing Photosynthesis and Cellular Respiration

Photosynthesis is the process of "depositing" energy, whereas cellular respiration is described as withdrawing energy..
Photosynthesis and cellular respiration differ in their use of carbon dioxide and oxygen.

Studying That Suits You

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

Description

This quiz covers key concepts of Section 9-2, focusing on the Krebs cycle and the electron transport chain. It explores how pyruvic acid is processed and the role of high-energy electrons in energy extraction during cellular respiration. Test your understanding with questions related to these biological processes.