PhotosynthesisPhotosynthesis

Michael SlempMichael Slemp

BELL WORKBELL WORK

Explain the difference between light Explain the difference between light dependent reactions to light independent dependent reactions to light independent reactions.reactions.

Use complete sentences and be descriptive.Use complete sentences and be descriptive.

ReviewReview

All cells need energy in form of ATPAll cells need energy in form of ATP Most animal cells need to eat energy-rich Most animal cells need to eat energy-rich

molecules like sugars to get their energymolecules like sugars to get their energy Some organisms, like plants, are able to Some organisms, like plants, are able to

produce their own energy via photosynthesis produce their own energy via photosynthesis or chemosynthesis. or chemosynthesis. They are called They are called producersproducers..

Sunlight energy

Photosynthesis Energy rich molecule (glucose)

Plants, animals and humans use glucose as source of energy

Types of EnergyTypes of Energy

Light EnergyLight Energy Energy from the sunEnergy from the sun Human use: solar calculators, solar heatersHuman use: solar calculators, solar heaters

Plants are able to convert light energy into chemical energy

during the process of photosynthesis

Chemical EnergyChemical Energy Energy hidden in the bonds of chemical molecules Energy hidden in the bonds of chemical molecules

(like sugar/glucose. ATP)(like sugar/glucose. ATP) This energy is released when bonds are brokenThis energy is released when bonds are broken

Pair SharePair Share

1.1. Describe the difference between light and chemical Describe the difference between light and chemical energy.energy.

2.2. Can humans convert light energy into chemical Can humans convert light energy into chemical energy?energy?

3.3. What organisms can convert light energy into What organisms can convert light energy into chemical energy?chemical energy?

4.4. What is this process called?What is this process called?

Pair SharePair Share

1.1. Describe the difference between light and chemical energy.Describe the difference between light and chemical energy. Light energy is the energy from sunlight and chemical Light energy is the energy from sunlight and chemical energy is hidden in bonds of chemical molecules.energy is hidden in bonds of chemical molecules.

2.2. Can humans convert light energy into chemical energy? Can humans convert light energy into chemical energy? NoNo

3.3. What organisms can convert light energy into chemical What organisms can convert light energy into chemical energy? energy? PlantsPlants

4.4. What is this process called? What is this process called? PhotosynthesisPhotosynthesis

PhotosynthesisPhotosynthesis

What organisms? What organelle?

Lets look closely at

the structure of chloroplast

Plants Chloroplast

Chloroplast Chloroplast

Outer membrane

Inner membrane

Thylakoid (coin-shaped,

membrane enclosed

compartment)

Granum (pl. grana)

stack of thylakoids

Stroma (fluid outside thylakoids)

Draw and label picture

in your notebook

Add to your notesAdd to your notes

CHLOROPHYLLCHLOROPHYLLPigment molecule responsible for sunlight absorptionPigment molecule responsible for sunlight absorption

Chlorophyll is found on the thylakoid membranes of chloroplasts

The main types are: chlorophyll a and chlorophyll b

Together they absorbs mostly red and blue wavelenghts (think of a rainbow)

Green wavelengths are being reflected (that’s why plants look green)

Pair SharePair Share

1

2

4)

5

3

Name all parts of chloroplast and answer

question.

What is the name of pigment molecule and where is it found?

Outer membrane

Inner membrane

Thylakoid (coin-shaped,

membrane enclosed

compartment)

Granum (pl. grana)

stack of thylakoids

Stroma (fluid outside thylakoids)

Pair SharePair Share Name all parts of chloroplast and answer

question.

What is the name of pigment molecule and where is it found?

Chlorophyll and it’s located on thylakoid membranes.

Process of PHOTOSYNTHESISProcess of PHOTOSYNTHESISPhotosynthesis is complicated process involving variety of molecules and enzymes

It can be summarized as:

6 CO2 + 6 H2O + sunlight energy C6H12O6 + 6 O2

Carbon dioxide + water + sunlight energy glucose + oxygen

2 steps:

1. Light-dependent reactions (happens in thylakoids)

2. Light-independent reactions (happens in stroma)

Light-dependentLight-dependent

Where?

Thylakoids

What is needed?

• Sunlight energy

• Water

• Chlorophyll

Steps:

• Chlorophyll absorbs sunlight energy

• Water molecule is broken down

• Oxygen is released

• Energy carried along thylakoid membrane is transferred to molecules that carry energy (ATP)At the end of the light-dependent reactions

we have energy-rich carriers (ATP) and released free oxygen.

Light-Light-inindependentdependent

Where?

Stroma

What is needed?

• Chemical energy from light dependent reaction (ATP)

• Carbon dioxide

Steps:

• In order to build larger carbon molecules, carbon dioxide molecules are added together in a cycle of chemical reactions.

• Energy from light dependent reaction is used.

• Molecule of simple sugar (glucose) is formed.

At the end of the light-independent reactions we have glucose molecule which

serves as a storage of chemical energy.

CompareCompare

Light dependent

(need chlorophyll)

Light-independent

(can happen at night)

Water

Oxygen Molecules that carry

energy (ATP)

Carbon dioxide

GLUCOSE

Stores chemical energy

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3 7

2

10

4 56

81

9

Fill in the blanks

Pair sharePair share

Light dependent

(need chlorophyll)

Light-independent

(can happen at night)

Water

Oxygen Molecules that carry

energy (ATP)

Carbon dioxide

GLUCOSE

Stores chemical energy

9 - Stroma

10 - thylakoids