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
Pair sharePair share
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