Review: Energy for Life

1. Define the following and explain their importance.

a. Photosynthesis –

b. Cell respiration –

c. Glucose -

The way plants make food (sugar) using light energy. At beginning of almost all food chains on Earth.

The way sugar is broken down to get energy. Howalmost all living things get energy.

The sugar all living things use for energy.

Hydrothermal vent

d. Chlorophyll –

e. Chloroplast –

f. Mitochondrion –

g. ATP -

The green pigment that absorbs light for photosynthesis.Plants couldn’t do photosynthesis w.out it.

The part of plant cells where photosynthesis happens.Plants couldn’t do photosynthesis w.out them.

The part of plant and animal cells where cell respirationHappens. Couldn’t break down sugar for energy w.out them.

The form of energy cells get from breaking downsugar. More usable form of energy than sugar.

Remember: plants do cell respiration too!

2. Explain the difference between autotrophs and heterotrophs, give examples of each.

• Autotrophs can make their own food; heterotrophs have to eat other living things for energy.

• Autotrophs: plants, most anything green• Heterotrophs: animals, mushrooms, fungi, bacteria,

most any non-green thing.

Why are mushrooms not considered autotrophic?

They aren’t green. No chlorophyll, no photosynthesis.

3. Write the chemical formula for photosynthesis using symbols and words to identify the reactants and products.

6CO2 + 6H2O + (energy) C6H12O6 + 6O2

Carbondioxide

water light glucose oxygen

reactants products

4. Write the chemical formula for cellular respiration using symbols and words to identify the reactants and products.

C6H12O6 + 6O2 6CO2 + 6H2O + energyglucose oxygen Carbon

dioxidewater ATP

reactants products

5. State 2 similarities between photosynthesis and cell respiration and 2 ways in which they are opposite reactions.

• Both involve sugar and energy.• Photosynthesis makes sugar, cell respiration breaks it down.• The equation for CR is the reverse of photosynthesis.

6. Describe how ATP and ADP molecules store and release energy for cells.

Energy released from ATP by breaking bond off 3rd phosphate, forming ADP

Energy stored by adding 3rd phosphate to ADP, forming ATP

In cell respiration, 36 ADP are converted into ATP….

C6H12O6 + 6O2 6CO2 + 6H2O + energy

glucose oxygen Carbondioxide

water ATP

36 ADP 36 ATP

7. Explain how almost all living things on Earth depend directly or indirectly on photosynthesis.• Almost every food chain on Earth begins with

photosynthesis.• Plants make food by photosynthesis. Animals eat

plants. Other animals eat animals that eat plants, etc.

8. Explain in terms of cell respiration why we need oxygen to live.• Cells need oxygen to break down glucose to get

energy for life processes.• Without energy, cells die, we die….

What does burning sugar and burning wax have in common? Both need oxygen

Suppose you came home and found a family member unconscious on the floor. What are the first two vital life functions you should check for? Explain in terms of cell respiration why these two functions are so important to check.

• Breathing and pulse/heart beat.• Breathing: make sure taking in

oxygen to break down sugar for energy.

• Pulse: make sure oxygen being pumped to all organs and cells so they can do cell respiration.

9. Discuss similarities and differences in how cells use glucose and ATP.

• Both forms of energy, both needed by cells.• Glucose has more energy, but less usable

form.• ATP has less energy, but more usable form.

Glucose like $100 bill, ATP like $1 bills

10. Give 3 examples of life processes that require energy.

• Moving• Heart beating• Thinking• Growing and developing• Digesting food• Transporting things in & out of cells• Making more cells

11. Explain the difference between manipulated variables, responding variables, and controlled variables in an experiment.

1 thing changed

Thing measured as response to manip. variable

Manip. Variable:

Resp. variable:

Controlled variables: Things kept same to make fair test

Questions?

Exit Slip

Q: Write the chemical equation for photosynthesis using symbols and words. Circle the reactants.

A:

Your name at bottom