Cell Processes

Part 1Respiration & Photosynthesis

Cell Processes 1/20/15

Key Question: Why do we need to eat food?

Initial Thoughts:

• Cells need energy to do work.• For example: moving your muscles, thinking

with your brain, fighting off illnesses, just to name a few.

Cellular Respiration(breaking down food)

• We need Oxygen and sugar (glucose) to get energy for our cells to do things.

• As a byproduct, CO2 (carbon dioxide) and H2O (water) are given off.

• We breathe in O2, breath out CO2

Photosynthesis

• Plants can make their own food using sunlight as energy.

• What organelle do plants use to do this?

ChloroplastIt’s what makes plants GREEN

PhotosynthesisThey absorb water through their roots

& CO2 through their leaves.

They use sunlight to power this transformation into food.

They store their food in the form of sugars (glucose).

Did you know?• When you eat potatoes, rice, beans, or wheat

flour, you are eating big molecules of glucose called starch, made through photosynthesis. Starches are a type of carbohydrate.

Evidence: Ps & Rsp Card SortPhotosynthesis and Cellular Respiration Activity• Work with a partner, but each of you must record

your equations & answers in your journal.• Answer in complete sentences.• When you have arranged your cards, raise your

hand and I will initial your paper for each equation.

Cellular Respiration(breaking down food)

glucose/sugar ATP

Reactants Products (what goes in) (What comes out)

H20 + CO2+ EO2 + C6H12O6

Photosynthesis

glucose/sugar

Reactants Products (what goes in) (What comes out)

H20 + CO2+ E O2 + C6H12O6

Photosynthesis

• As a byproduct, plants give off Oxygen

• We consume/eat plants and need oxygen they make. We are called CONSUMERS.

• This why plants and all photosynthetic organisms are called PRODUCERS.

The Cycle

CO 2

O 2Producers

Consumers

Analysis Questions1. Explain what gases are involved in

Photosynthesis and Respiration. Which ones are inputs, and which are by-products?

2. Compare the chemical equations for photosynthesis and cellular respiration. How are they similar? How are they different?

3. Do you think plants do cellular respiration? Explain your reasoning.

SummaryIn a well developed paragraph:– What did you think before about how plants & animal

cells use food? (look back at your initial thoughts)– What did you learn about how plants & animal cells

use food? Be specific! (look back at your evidence section).

– What evidence do you have that you learned this?– Further Thoughts

Make sure this is thoughtful and thorough.

Reflection

• Create a diagram that shows how the gases are recycled between producers and consumers.

Big Idea

• - (make your own big idea)