Cellular Respiration (the big picture)ktp10



Name: ______________________________________

Unit 2: Matter & Energy

Energy in Plants

As you remember from prior readings and activities, cellular respiration is a process to create cellular energy by breaking down sugars to glucose. During Cellular Respiration, sugar is broken down to CO2 and H2O, and in the process, ATP (Energy) is made that can then be used for cellular work.

The overall reaction for cellular respiration is below.

C6H12O6 + 6O2 -------------------> 6CO2 + 6H2O + ~36 ATP (or 2 ATP and 34 ATP)

Actually, cellular respiration is the reverse reaction of photosynthesis. Photosynthesis is the process to create sugars (glucose) in plants. However, chemically, the steps involved are very different than cellular respiration.

Photosynthesis is the process by which CO2 and H2O are used to make sugars and starches.

[pic]

Only photosynthetic cells can make sugar using photosynthesis, but ALL cells need to be able to break down sugars they take in from their environment and turn those sugars into energy to be used in cellular work (cellular respiration).

In summary, cellular respiration is an almost universal process by which organisms utilize the sugars in their food to produce enough energy to perform all the necessary actions of living creatures.

Magic School Bus – Get Planted (22 minutes)

Complete the questions below using the video and prior knowledge.

1. What do all living things need to grow?

2. What is another word with a similar meaning to “speculation”?

3. Why do the roots move?

4. What is the job of the small hair-like structures on the roots?

5. What do roots collect?

6. Which direction does the water move?

7. Why is Phoebe so hungry? What part of the equation is she missing?

8. What are the green blobs called?

9. Where are the openings in the leaf located?

10. Think back to Plant Systems in Unit 1... what are the openings called? What is the name of the part that opens and closes the openings?

11. What does the opening in the leaf allow to enter?

12. Why do the chloroplasts move?

13. What is the sunlight’s function?

14. What is the formula to create “white stuff”?

15. Think back to the “Food for Energy” reading… what is the white food?

16. What can’t Phoebe collect sunlight?

17. Which direction do plants grow?

18. Do plants use any other living organisms to create food?

Photosynthesis Reading

Not all of the light from the Sun makes it to the surface of the Earth. Even the light that does make it here is reflected and spread out. The little light that does make it here is enough for the plants of the world to survive and go through the process of photosynthesis. Light is actually energy, electromagnetic energy to be exact. This is why plants will not grow with a normal light bulb and no sun.

Photosynthesis is the process by which green plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. The conversion of unusable sunlight energy into usable chemical energy is associated with the actions of the green pigment chlorophyll. The photosynthetic process uses water and releases the oxygen that humans absolutely must have to stay alive. Oh yes, we need the food as well!

We can write the overall reaction for photosynthesis as:

6H2O + 6CO2 ----------> C6H12O6+ 6O2

Leaves and Leaf Structure

Plants are the only photosynthetic organisms to have leaves, but not all plants have flat leaves. Some have modified leaves like a cactus has spines.

The raw materials of photosynthesis, water and carbon dioxide, enter the cells of the leaf through the stoma. Guard cells protect the stoma. The products of photosynthesis, sugar and oxygen, leave the leaf also through the stoma.

Within the plant cells are organelles called chloroplasts. Within this organelle is the chlorophyll that captures the light from the Sun.

Molecules of Photosynthesis

Chlorophyll is found in the chloroplast of green plant leaves. Other molecules involved in photosynthesis are water (H2O), carbon dioxide (CO2), oxygen (O2) and glucose (C6H12O6). Carbon dioxide and water combine with light to create oxygen and glucose. That glucose is used in various forms by every creature on the planet. Animal cells require oxygen to survive.

Light and Dark (Calvin) Reactions

The whole process does not happen all at one time. The process of photosynthesis is divided into two main parts. The first part is called the light dependent reaction. This reaction happens when the light energy is captured and pushed into a chemical called ATP. The second part of the process happens when the ATP is used to make glucose. This second part is called the light independent reaction.

Draw a diagram to illustrate the process of photosynthesis:

Write the equation that shows the process of photosynthesis:

-----------------------

SUMMARY:

SUMMARY:

SUMMARY:

SUMMARY:

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download