Bellringer

• Why do we eat?

• What is needed in order to make a fire burn?• Burning Fuel

Cellular Respiration

Chapter 2 Lesson 2

What Is Cellular Respiration?• All of our energy comes

from food• Cellular respiration– The process by which cells

break down food (glucose) and release energy

• Living things need a constant supply of energy so they carry out cellular respiration continuously

What is Cellular Respiration?• Storing and Releasing Energy– When you eat you add to your body’s energy

savings by storing glucose– When you need energy, your cells break down the

glucose through cellular respiration• Breathing and Respiration– Respiration can mean breathing (moving oxygen

into your lungs)– The oxygen is used to carry out cellular respiration

Mitochondria

• The powerhouse of the cell

• In the mitochondria– Small sugar molecules

are broken down with oxygen releasing large amounts of energy

• Cristae-folds where cellular respiration occurs

Cellular Respiration Stage 1Glycolysis

• Occurs in the cytoplasm• Glucose is broken down into smaller

molecules WITHOUT oxygen releasing a small amount of energy

Cellular Respiration Stage 2Krebs Cycle and Electron Transport

• In the mitochondria• Small molecules are broken down in the

presence of oxygen• This forms carbon dioxide, water, and large

amounts of ATP– Chemical energy of the cell

The Cellular Respiration Equation

Comparing Two Energy Processes

Comparing Two Energy Processes

What Happens During Fermentation?• Fermentation– Process in which cells release energy from food

without using oxygen– Without oxygen the products of cellular

respiration are different• Alcoholic Fermentation– Ethyl alcohol is formed by yeast and some bacteria

• Lactic Acid Fermentation– Lactic acid is formed by muscle cells when cellular

respiration is done without oxygen