Page

(UNIT 1 Cell Metabolism: Photosynthesis, cellular respiration and fermentation)

Chapter 8 Photosynthesis

8.1 energy and Life

Session 1 Diagnostic activity- Answer the questions in plenary.

1- What is photosynthesis?

__________________________________________________________________________________________________________________________________________________________________________

2- Name three examples of organisms that carry out photosynthesis.

_____________________________________________________________________________________

3- What is the importance of photosynthesis to living things?

__________________________________________________________________________________________________________________________________________________________________________

Chemical energy and ATP

ATP as a Charged Battery An analogy takes two things that seem to be different and shows how they can be similar.

1. How is a partially charged battery like ADP?

2. Why do cells contain only a small amount of ATP?

A. ATP cannot store large amounts of energy for a long time.

B. ATP releases energy too quickly.

C. ATP cannot carry out active transport.

D. ATP has only two phosphate groups.

Chemical Energy and ATP

Chemical Energy Living things use chemical fuels. One of the most important compounds that cells use to store and release energy is ATP.

Follow the directions. Then answer the questions.

1. Trace the outlines of the adenosine molecule and the three phosphate groups.

2. Cut out each phosphate group.

3. Arrange the phosphate groups on the adenosine molecule to form a molecule of ATP.

4. When ATP is changed to ADP, it releases energy. Change your ATP molecule so that it forms ADP. What change did you make?

5. ADP can be converted into ATP. Change your ADP molecule into ATP. What change did you make?

6. Fill in the blanks with two or three. The primary difference in the structures of ATP and ADP is that ATP has phosphate groups and ADP has phosphate groups.

Write a brief summary that mentions the importance of the ATP molecule regarding how it stores and releases energy.

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Session 2

Heterotrophs and autotrophs

Fill in the following table.

Heterotrophs

Autotrophs

Define the term

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Example

History of the discovery of photosynthesis

Write the contributions that the following scientist made on photosynthesis.

Jan Baptiste van Helmont _______________________________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Joseph Priestley _______________________________________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Jan Ingenhousz ________________________________________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Melvin Calvin _________________________________________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

8.1 Assessment

1- a. Review What is ATP and what is its role in the cell?

__________________________________________________________________________________________________________________________________________________________________________

b. Explain How does the structure of ATP make it an ideal source of energy for the cell?

__________________________________________________________________________________________________________________________________________________________________________

c. Use Analogies Explain how ADP and ATP are each like a battery. Which one is partially charges and which one is fully charged? Why?

__________________________________________________________________________________________________________________________________________________________________________

2- a. Review What is the ultimate source of energy for plants?

__________________________________________________________________________________________________________________________________________________________________________

b. Explain How do heterotrophs obtain energy? How is this different from how autotrophs obtain energy?

__________________________________________________________________________________________________________________________________________________________________________

c. Infer Why are decomposers, such as mushrooms, considered heterotrophs and nos autotrophs?

__________________________________________________________________________________________________________________________________________________________________________

8.2 Photosynthesis: An Overview

Session 3 Chlorophyll and chloroplasts

Write statements that indicate the relationship between light, pigments and chloroplasts.

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Make a drawing of the chloroplast and list the names of its components and structures.

Chlorophyll and Chloroplasts

In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll. Inside chloroplasts are thylakoids. The region outside the thylakoid is the stroma.

Answer the questions.

1. Where do the light-dependent reactions occur? Circle the correct answer.

thylakoids stroma

2. Where do the light-independent reactions occur? Circle the correct answer.

thylakoids stroma

3. Is the following statement true or false? In plants, photosynthesis takes place in the chloroplasts.

4. The function of chlorophyll is

A. to protect a plant from losing water.

B. to help plants absorb oxygen.

C. to protect the plant cell.

D. to capture energy from the sun.

Chlorophyll and Chloroplasts

Photosynthesis in plants takes place in organelles called chloroplasts. Within each chloroplast is a fluid-filled area called the stroma. Also inside each chloroplast are many saclike membranes called thylakoids. Thylakoids are connected to each other in stacks. Each stack is a granum.

Complete the Venn diagram to compare the stroma and a granum in a chloroplast. Use the phrases below. One has been done for you.

( contains pigments light-dependent reactions fluid portion of chloroplast located within a chloroplast are a part of photosynthesis stacks of thylakoids)

Answer the questions. Circle the correct answer(s).

1. Which reactions change the energy of sunlight to energy-rich carriers?

light-dependent reactions light-independent reactions

2. Which two reactants are needed for light-dependent reactions?

carbon dioxide light oxygen water

3. Which two reactants are needed for light-independent reactions?

carbon dioxide energy-rich compounds oxygen stroma

Photosynthesis overview

Write down the general chemical equation of photosynthesis, as well as the general stages.

8.2 Assessment

1- a. Review Why are pigments such as chlorophyll needed for photosynthesis?

__________________________________________________________________________________________________________________________________________________________________________

b. Predict How well would a plant grow under pure yellow light? Explain your answer.

____________________________________________________________________________________