Respiration

Think, pair, share

• The word equation for respiration.

• Where aerobic respiration takes place in the cell.

• Why do cells need energy?

Energy in Cells

Cells need energy for;

Cell division, growth, muscle contraction and synthesising large molecules.

Where does this energy come from?

Energy in Food

How do you know that there is energy present in the malteser?

The Respiration Equation

Glucose + Oxygen Energy + Carbon + Water (ATP) Dioxide

From Our food

Can be used for Cell activity e.g.

Muscle contraction

Respiration

Respiration is a series of enzyme controlled reactions that releases the chemical energy stored in glucose.

ATP

• The energy from glucose is used to form ATP by making a bond between ADP (adenosine di-phosphate) and Pi (inorganic phosphate).

Energy from glucose

ATP• ATP carries the energy to a cell which needs

energy and breaks down into ADP and Pi.

Energy released from ATP

The energy released from the bond can be used in cell division, muscle contraction and making proteins.

ATP

ADP + Pi

ENERGYPUT IN

ENERGYRELEASED

RespirationOf glucose

Used forCell

Activity

The Energy Cycle

Quick Questions

1.What is respiration?

2.What is the equation for respiration?

3.What form does the energy take when it is released from food?

4. What does ATP stand for?

5. What can ATP be used for?

Aerobic Respiration

Breakdown of glucose to release energy in thepresence of oxygen is a two step process:

1. Glycolysis: Glucose is split in two becomingpyruvic acid

2. Breakdown of pyruvic acid into simple products

Using Oxygen

Stage 1: Glycolysis

Glucose Splitting

Glucose (6 carbons)

Pyruvic Acid (3 carbons)

enzymecontrolled reactions

How many molecules of pyruvic acid come from 1 molecule of glucose?

Stage 2: Breakdown of pyruvic acid

Pyruvic acid + oxygen

carbon dioxide + water

enzymecontrolled reactions

When is ATP produced?

Glucose

Pyruvic Acid

carbon dioxide + water

+ oxygen

2ADP + 2Pi

2ATP

36 ADP + 36 Pi

36 ATP

How many molecules of ATP are produced from 1 molecule of pyruvic acid?

Glucose

Pyruvic Acid

carbon dioxide + water

+ oxygen

2 ATP

36 ATP

Total = 38 ATP

ATP production

Anaerobic Respiration in Plants and Yeast

no oxygenGlucose

Pyruvic Acid

Ethanol and Carbon Dioxide

2ADP + Pi

2ATP

No ATP

Total2 ATP

Effects of Lactic Acid in Muscle

Glucose

Pyruvic Acid

Lactic acid

heavy exercise

BUILD UP OXYGEN DEBT

recovery period

OXYGEN DEBT REPAID

+ oxygen

3.5.3 Comparing aerobic and anaerobic

Aerobicrespiratio

n

Anaerobic respiration animals

Anaerobic respiration plants

Glycolysis

ATP yield

Products

Yes Yes Yes

38 2 2

Carbon dioxide& water

Lactic acid Ethanol &Carbon dioxide

Time (mins)

Force (Newtons)

0 4005 3807 39010 35018 33020 29022 30025 29026 27030 240

Produce a graph using the information below:

Explain why the force used by the muscle is decreasing.

Questions

1. Define the term anaerobic respiration.2. Explain why lactic acid builds up in the

muscles.3. Identify 2 conditions necessary for the

oxygen debt to be repaid.4. Give 3 differences between the breakdown

of a glucose molecule in a root cell which respires in;

a) well aerated soil. b) anaerobically in flooded soil.