Cellular Metabolism

Autotrophs and Heterotrophs

Autotrophs are organisms that make their own glucose.

How Organisms Obtain Energy

Heterotrophs are organisms that need to ingest glucose to obtain energy.

All organism need glucose!

ATP: The Unit of Cellular Energy

ATP releases energy when the bond between the second and third phosphate groups is broken, forming a molecule called adenosine diphosphate (ADP) and a free phosphate group.

How Organisms Obtain Energy

http://www.youtube.com/watch?v=n-Tw2XbX7aY – watch this clip

What chemical bond in ATP releases energy when

broken?

A. phosphateB. sulfurC. oxygenD. potassium

Describe Photosynthesis• The process of changing light energy to

chemical energy • Energy stored as sugar• Occurs in plants and some algae • Plants need light energy, CO2, and H2O • Takes place in the chloroplasts, using

chlorophyll, the green pigment in plants

What three things do plants need for

photosynthesis?• Light energy• CO2

• H2O

What happens during photosynthesis?

• Plants capture light energy and use that energy to make glucose

• Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose

• Oxygen is also released in this reaction

What happens during photosynthesis?

• Carbon dioxide enters the leaf through holes called stomata

• CO2 combines with the stored energy in the chloroplasts through a chemical reaction to make glucose

• The sugar is moved through tubes in the leaf to the roots, stems and fruits of the plants

• Some of the sugar is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue

Why is this important to us?• We cannot make our own food (glucose,

energy), we must get our food from plants.• Plants are the first step in the food chain.• The oxygen released during

photosynthesis is necessary for all living things.

What is the Equation for the Chemical Reaction of

Photosynthesis?

What is the equation for the chemical reaction of

photosynthesis?

Reactants Products

Think about the following…

1) What happens during photosynthesis?

2) Why is this important?

3) What are the reactants and products for photosynthesis?

Turn to your shoulder partner and talk about these points.

Press Pause, Think, & Share

What did you discuss?• What happens during photosynthesis?• Plants capture light energy and use it to convert it to

glucose.• Why is this important? • Glucose is made that organisms needs as well as

oxygen.• What are the reactants and products for photosynthesis?

What does ADP and ATP stand for? What is the role of this

molecule inside a cell?

Time to Write

• Using the graphic organizer that was handed to you, fill in the missing information.

• Trim the border and then glue this in your composition notebook.

Okay, the sugar is made…Now what?

Cellular Respiration

What is Cellular Respiration?Once the energy that was in sunlight is

changed into chemical energy by photosynthesis, an organism has to transform the chemical energy into a a form that can be used by the organism.

This process is cellular respiration.

Overview of Cellular Respiration

Organisms obtain energy in a process called cellular respiration.

The equation for cellular respiration is the opposite of the equation for photosynthesis.

Describe Cellular Respiration• The breakdown of glucose molecules to

release energy

• Takes place in all living things

• There are two types– Aerobic and anaerobic

Aerobic Cellular respiration

• Takes place in the presence of oxygen• More energy is released

Glucose + Oxygen ATP + CO2 + H2O

Anaerobic Cellular respiration• Takes place WITHOUT oxygen• Less energy is released • Typically called fermentation• Two types

– Lactic acid fermentation• Occurs in muscles without oxygen and produces

lactic acid– Alcoholic fermentation

• Occurs in organisms without oxygen and ethanol is produced

Think about the following…

1) What happens during cellular respiration?

2) Why is this important?

3) What are the reactants and products for cellular respiration?

Turn to your should partner and talk about these points.

Press Pause, Think, & Share

What did you discuss?• What happens during cellular respiration?

– Glucose is broken down to a smaller energy, ATP

• Why is this important? – Glucose is too large to for the cell to utilize

• What are the reactants and products for photosynthesis?• Aerobic= Glucose + Oxygen ATP + CO2 + H2O

• Anaerobic– Alcoholic fermentation= Glucose ATP + CO2 + H2O+ ethanol

– Lactic fermentation = Glucose ATP + CO2 + H2O+ lactic acid

Time to Write

• Using the graphic organizer that was handed to you, fill in the missing information.

• Trim the border and then glue this in your composition notebook.