Do animals breath?How do animals get their energy?

Cellular Respiration

Cellular Respiration EquationC6H12O6 + 6O2 6CO2 + 6H2O + cell energy

(ATP)

In words…..Glucose + oxygen carbon dioxide + water +

energy

1. The process called cellular respiration releases the energy in carbohydrates in two steps.

1. Glycolysis2. Krebs Cycle

2. All Cells perform cellular respiration to get energy/ATP

Cells and Energy – Cellular Respiration

Step 1: Glycolysis glyco – sugar lysis – to break down

• Glycolysis occurs in the cell’s cytoplasm.• One glucose molecule breaks into 2 smaller

molecules called pyruvate and also makes 2 ATP molecules

Step 2a: Krebs Cycle (Oxidative Respiration)

• **Only if Oxygen is present• occurs in the mitochondria• The products from Glycolysis go

through aerobic respiration.• In this process pyruvate is

turned into Acetyl CoA to begin the Krebs Cycle

• The Krebs cycle produces 34

ATP molecules!!

Step 2b: Fermentation• Only if oxygen is NOT present.• 2 types of fermentation:– Alcoholic fermentation:

• EX: In yeasts it produces alcohol and carbon dioxide. • It causes bread dough to rise. Another example is grapesalcohol.

– Lactic Acid fermentation• Occurs in muscle cells, • The pyruvic acid accumulates as a result of glycolysis

producing lactic acid, which makes muscles sore.