Chp 1-3 Cells and Energy

• All cells can release energy from food molecules.

– Plants and Animals

• Only some cells can make food molecules using light energy

• There are 2 ways to release energy.

– Cellular Respiration

– Fermentation

• ATP—adenosine triphosphate—a usable MOLECULE of energy.

Simplify

• A series of chemical reactions that transforms the energy in food molecules to useable energy.

Food Energy

Glucose ATP•What needs to do this?

•All cells in every living thing!!

Cellular Respiration

• Chemical reactions that change the energy in food molecules to usable energy.

• Occurs in:

– Cytoplasm and Mitochondria

• Uses:

– Oxygen, glucose

• Makes:

– 36 ATP Molecules

1.3 Cells and Energy

Fermentation• Chemical reactions that change the energy in food

molecules to usable energy.

• Occurs in:

– Cytoplasm only

• Uses:

– NO Oxygen

– Glucose

• Makes:

– 2 ATP Molecules

1.3 Cells and Energy

What does yeast look like?

Yeast Air BalloonsWhat’s going on?

There are about 160 known species of yeast. Bakers yeast is used in kitchens to bake. Just one gram holds about 25 billion cells.

As the yeast feeds on the sugar, it produces carbon dioxide gas in a process called CELLULAR RESPIRATION when there is oxygen. With no place to go but up, this CO2 slowly fills the balloon.

1.3 Cells and Energy

Yeast Air Balloons continued

• Once the oxygen is used up, then alcohol is produced in a process call FERMENTATION, like making beer and bread.

• So most yeast is like us they prefer to make energy using oxygen, but they do have a backup.

• When we are making beer, wine, bread or even root beer, we are waiting for fermentation to take over cellular respiration.

1.3 Cells and Energy

Types of Fermentation

• Types of fermentation

– Lactic acid fermentation

– Alcohol fermentation – not for humans

Predict: What would happen if your cells could not perform lactic acid fermentation?

ANSWER:

• Our muscle cells would be limited to cellular respiration, decreasing energy production and probably endurance.

• This means probably NO SPORTS or anything else that takes use to an aerobic level.