Chapter 3Cell Processes

Section 3: Energy for Life

III. Energy for LifeA. What is Metabolism?

1. Metabolism is the total of all chemical reactions that happen inside an organism.

a. Example 1: Rate at which your body burns food.

b. Rate your lungs convert oxygen for cellular use.

III. Energy for Life2. Enzymes: chemicals that help the body

go through metabolism. a. Enzymes cause a change but the enzyme

itself is not changed. 1. Example: Can opener and a can of spaghettio’s

b. Enzymes can cause things to come apart OR cause things to join together.

c. There is a specific enzyme for EVERY chemical reaction that the body undergoes

III. Energy for LifeB. Producers and Consumers

1. All organisms are either producers or consumers.

2. Producers make their own food. a. Plants, green bacteria, green protists.b. Producers us a process called photosynthesis.

3. Consumers cannot make their own food.a. Animals, non-green bacteria, non-green

Protists, Fungi b. Consumers eat producers or other consumers.

III. Energy for LifeC. Photosynthesis

1. Process of producers taking in sunlight and carbon dioxide to make food.

2. Use a green pigment called chloryophyll.

3. Even though producers make their own food; they must then be able to break it down to be used for energy.

III. Energy for LifeD. Producing Carbohydrates

1. Producers that use photosynthesis are usually green because they contain chlorophyll.

2. Photosynthesis produces glucose (which is a carbohydrate), using raw material from the air and soil.

3. The captured light energy used in photosynthesis also helps hold the sugar molecules together.

III. Energy for LifeE. Storing Carbohydrates

1. Plants make more sugar during photosynthesis than they need to survive.

a. Excess sugar is changed and stored as starches or used to make other carbohydrates that are used as food for growth, maintenance, and reproduction.

2. No matter what you eat, photosynthesis was involved directly or indirectly in its production. (we often eat the excess sugar stored by plants!!!)

III. Energy for LifeF. Cellular Respiration

1. The process of organisms taking food and breaking it down to energy.

2. Every cell of every organism in the world goes through respiration!!!!!

3. Read page 83 in textbook (Respiration)

III. Energy for LifeG. Breaking Down Carbohydrates

1. Food molecule most easily broken down by cells are carbohydrates.

2. Respiration of carbs begins in the cytoplasm.

a. Carbs are broken down into glucoseb. Glucose then broken down into simpler

molecules.c. As this happens energy is released.

III. Energy for Life3. The two simpler molecules are broken

down in the mitochondria of plants, animals, fungi, and many other organisms.

4. This process uses oxygen, releases MUCH MORE energy, and produces carbon dioxide and water as wastes.

5. Right now….millions of your cells are breaking down glucose, releasing energy, and producing Carbon Dioxide and Water!!!!!

III. Energy for LifeH. Fermentation

1. Sometimes cells don’t have the oxygen they need to go through respiration; cells will undergo respiration without enough oxygen; this is called FERMENTATION.

2. Like respiration, fermentation begins in the cytoplasm….but the simple molecules do not move into the mitochondria.

3. Fermentation produces lactic acid or alcohol, and carbon dioxide as wastes.

III. Energy for LifeH. Fermentation

4. When cells make energy without enough O2, they make an acid called Lactic Acid.

a. When this builds up in the muscles you cramp!!5. When yeasts are in heat they go through

fermentation and make bread rise. a. In this process they give off CO2, this is why all

baked goods have little air pockets in them. 6. Fermentation produces LESS ENERGY

then respiration!!!!

III. Energy for LifeH. Fermentation

III. Energy for LifeH. Fermentation

III. Energy for LifeI. How are Photosynthesis and Respiration Related?

1. What is produced in photosynthesis is used in respiration and vice versa!!!

2. Respiration and Photosynthesis are directly liked together….they need each other to continue the process!!!!