CCGPS

• SB3. Students will derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems.– a. Explain the cycling of energy through the

processes of photosynthesis and respiration.• We will discuss:

– Photosynthesis– Cellular Respiration– Fermentation

Assessments

• Quizzes– Photosynthesis– Cellular Respiration– Fermentation

• Photosynthesis and Cellular Respiration Project

We are going to…

• work in the classroom and the computer lab

• take notes• complete our homework• learn!!!!!

Photosynthesis and Cellular Respiration Project

• Design a project that will show information about photosynthesis and cellular respiration and the connections between the two.

• Can create one of the following:– Children’s Storybook– Song– Recipe– Play– Prezi

• Required to create a handout and present final product

PhotosynthesisSections 4.2-4.3

The overall process of photosynthesis produces sugars that store chemical

energy.

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Overview• All energy on earth comes from the sun.• We depend on:

– Plants– Algae (underwater plants)– Cyanobacteria (photosynthetic bacteria)

• To provide this energy to us!

Overview

Overview• Photosynthetic organisms are producers.• Producers make their own source of

chemical energy.• Plants use photosynthesis and are

producers.• Photosynthesis captures energy from

sunlight to make sugars.

Overview• Carbon dioxide and water are taken in by

plants• Plants absorb light energy and convert it to a

usable form.– ATP

• Energy is used to “fix” carbon dioxide into sugar molecules– Chemical energy

• Sugar is converted to starch and stored for use by the plant, and by animals when they eat plants.

Chlorophyll• Chlorophyll is a

molecule that absorbs light energy.

• In plants, chlorophyll isfound in organelles called chloroplasts.

leaf

leaf cell

chloroplast

Plants are green because of the pigment chlorophyll.

(which absorbs light energy)

• During the fall, the green chlorophyll pigments are greatly reduced revealing the other pigments, this is the reason leaves turn brown in the fall.

• Carotenoids are pigments that are either red or yellow.

• Photosynthesis takes place in two parts of chloroplasts.–grana

(thylakoids)–stroma

• chloroplast

• stroma

• grana (thylakoids)

Chloroplasts• Have TWO

membranes– A “bi-bilayer!”

• The inner membrane is called the thylakoid.

• The thylakoid is folded and looks like stacks of coins called granum (grana=singular).

• The stroma is the space surrounding the granum.

Image source: http://www.daviddarling.info/encyclopedia/C/chloroplasts.html

Chloroplasts• Chlorophyll

molecules are embedded in the thylakoid membrane

• Act like a light “antenna”

• These molecules can absorb sunlight energy.

Image from Biology 11: College Preparation. Pg 73. Nelson, Toronto. 2003.

Light (dependent)Reactions• Happen ONLY in sunlight

– Hence they depend on light!– Water is also required

1. Light energy is absorbed by chlorophyll molecules in the thylakoid

2. The energy generates molecules of ATP (ADP converted to ATP)

3. Convert NADP+ to NADPH (Electron Carriers)-Energy then goes to Light Independent reaction

4. Produce Oxygen (O2) gas

Light (dependent)Reactions

Image from: Biology 11: College Preparation. Pg 74. Nelson, Toronto. 2003.

Light (dependent)Reactions

Light Independent Reactions(formerly the “dark reactions”)

• Happen in sunlight, and in the dark.– Hence “independent of light”– Makes sugars

1. Takes place in the stroma.

2. CO2 enters from the atmosphere

3. ATP generated by sunlight drives the Calvin Cycle.

4. Monosaccarides (eg. glucose) are manufactured in the cycle.

5. Monosaccarides are used to “build” polysaccharides (eg. Starch).

Light Independent Reactions(formerly the “dark reactions”)

Image from: Biology 11: College Preparation. Pg 74. Nelson, Toronto. 2003.

Light Independent Reactions(formerly the “dark reactions”)

Overall ReactionWhat is the equation for photosynthesis?

carbon dioxide + water glucose + oxygen + energy

6CO2 + 6H2O C6H12O6 + 6O2 + energy

• C6H12O6

• granum (stack of thylakoids)

• thylakoid

•sunlight

• 1 six-carbon sugar

• 6H2

O

• 6CO2

• 6O2

• chloroplast• chloroplast• 1

• 2

• 4• 3

• energy

• stroma (fluid outside the thylakoids)

Sun

LIGHT

H2O CO2

Light Dependent Reactions

Calvin Cycle

CHLOROPLAST

SugarsO2

Factors that affect the rate of Photosynthesis are…

• Availability of Water

• Temperature

• Intensity of Light

• Concentration of CO2