Lesson Overview Lesson Overview Cellular Respiration: An Overview Objectives 9.1 Cellular Respiration -Explain where organisms get the energy they need

Lesson Overview Cellular Respiration: An Overview

Objectives 9.1 Cellular Respiration

-Explain where organisms get the energy they need for life processes.

-Define cellular respiration.

-Compare photosynthesis and cellular respiration.


Chemical Energy and Food

Food molecules contain chemical energy that is released when its chemical bonds are broken during a process called CELLULAR RESPIRATION.


What is a Calorie?Energy stored in food is expressed in units called calories.

A Calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.


Overview of Cellular RespirationIf oxygen is available, organisms can obtain energy from food by a process called cellular respiration.

Equation:6 O2 + C6H12O6 6 CO2 + 6 H2O + Energy

In words:Oxygen + Glucose Carbon dioxide + Water + Energy


Stages of Cellular Respiration

The three main stages of cellular respiration are:

1. Glycolysis2. Krebs cycle3. The electron transport chain


Stage 1: Glycolysis

Glycolysis is anaerobic and produces only a small amount of energy.

*2 ATP molecules*


Stage 2: Krebs Cycle

During the Krebs cycle, a little more energy is generated using pyruvic acid to power the Electron Transport Chain.

*2 ATP molecules*


Stage 3: The Electron Transport Chain

The electron transport chain produces the bulk of the energy in cellular respiration by using oxygen.

*32 net ATP molecules*


Aerobic vs AnaerobicAerobic = with oxygen

Anaerobic = without oxygen


Photosynthesis and Cellular Respiration

Photosynthesis and cellular respiration are opposite processes.

The energy flows in opposite directions.


True or False

1. Either cellular respiration or fermentation can be used to release

energy, depending on the presence of carbohydrates.

_________________________

2. The Krebs cycle releases energy in the form of ATP.

_________________________

3. Electron carriers bring electrons from glycolysis and the Krebs

cycle to the electron transport chain. _________________________

4. Without the Krebs cycle, the electron transport chain cannot

function. _________________________


ANSWERS

1. Either cellular respiration or fermentation can be used to release

energy, depending on the presence of carbohydrates. False,

oxygen

2. The Krebs cycle releases energy in the form of ATP. True

3. Electron carriers bring electrons from glycolysis and the Krebs

cycle to the electron transport chain.True

4. Without the Krebs cycle, the electron transport chain cannot

function. True

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Lesson Overview Lesson Overview Cellular Respiration: An Overview Objectives 9.1 Cellular Respiration -Explain where organisms get the energy they need