1. We don’t do it, but we need it!
Photosynthesis
We don’t do it, but we need it!

2. Autotroph Heterotroph Photosynthesis Cell Respiration
Vocabulary
Autotroph
Heterotroph
Photosynthesis
Cell Respiration

3. Energy Flow Energy Sources
Organisms require a constant source of energy to survive.
Without some type of energy input, organisms die.
Energy Sources
The sun is the ultimate energy source for life
It provides light energy

4. Energy Sources
The energy provided by the sun is captured by plants, algae, and some types of bacteria and stored as food through photosynthesis.

5. Energy Sources
Animals graze on the grass and energy (originally from the sun) is transferred from the grass to the animal.

6. Energy Sources
Animals feed on other animals, and the energy is transferred from one animal to another.
Sun  plants  animal  other animals

7. Energy Sources
Organisms can be categorized by how they get their energy. There are two types of organisms:
Autotrophs
Heterotrophs

8. Autotrophs
Autotrophs get energy directly from the sun through photosynthesis.
Ex: Plants, algae, some types of bacteria

9. Heterotrophs
Heterotrophs are organisms that get their energy from sources other than the sun.
Ex: Humans, wolves, cows, insects, etc.

10. ATP Many of the cell’s activities require energy.
The energy used by cells is called ATP (adenosine triphosphate) or ADP (adenosine diphosphate)

11. ATP

12. ATP and ADP
ATP is a molecule that has three phosphate groups. The energy that ATP provides is stored in the bonds of the phosphate groups.
How many phosphates are in ADP?

13. Photosynthesis
Photosynthesis is the cellular process through which organisms containing chlorophyll convert light energy into chemical energy.
Chlorophyll is the green pigment inside chloroplasts.

14. Pigments
Chlorophyll is a pigment that is present in plants’ leaves, stems, etc.
There are several types of pigments (of different colors).
Pigments work like a light antenna.

15. Chlorophyll Chlorophyll only absorbs certain wavelengths of light.
They absorb red, orange, yellow, blue, and purple. They reflect green.
Photosynthesis takes place in the chloroplasts of plant cells.

16. Chloroplasts
Chlorophyll is inside the thylakoid membranes.

17. Chloroplasts Thylakoids are the individual disk-shaped structures.
Grana are stacks of thylakoids
Stroma is the jelly-like material surrounding the grana.

18. Photosynthesis Overview
During photosynthesis, plants and other autotrophs use the sun’s energy, water, and carbon dioxide, to make sugars and oxygen.
The energy stored as glucose can be used to make ATP.

19. Photosynthesis is:
The conversion of carbon dioxide and sunlight into glucose.
Formula- 6CO2 + 6H2O C6H12O6 + O2
Done by the following organisms- plants, algae, phytoplankton, cyanobacteria
Sunlight

20. Stages of Photosynthesis
1. Light Dependent reactions- Light is captured and turned into glucose
Occurs in thylakoids of the chloroplast
Produces energy carrying molecules that is required for light independent reactions.
Water and light goes in and ATP,NADPH, and Oxygen comes out
Occurs in stacks of thylakoids
2. Calvin Cycle-Light independent(Dark reactions)
In stroma of the chloroplast(the space in between the thylakoid
Carbon Dioxide, ATP, and NADPH go in and Glucose comes out
Carbon dioxide from atmosphere is “fixed” into glucose
C6H12O6

21. Where does photosynthesis occur?
Leaves of plants, most importantly in PLASTIDS
Chloroplasts- the main location of photosynthesis
Full of chlorophyll
2 types
Chlorophyll A & chlorophyll B
Chromoplasts
Carotenoids- yellow and orange pigments
Lycopin- red pigment

22. Absorption Spectrum of Photosynthesis

23. Factors that effect photosynthesis
1. Carbon Dioxide Concentration
Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesize if there is insufficient carbon dioxide.

24. Factors that effect photosynthesis
2. Temperature
If it gets too cold, the rate of photosynthesis will decrease. Plants cannot photosynthesize if it gets too hot.

25. Factors that effect photosynthesis
3. Light intensity
Without enough light, a plant cannot photosynthesize very quickly, even if there is plenty of water and carbon dioxide. Increasing the light intensity will boost the speed of photosynthesis.

26. What do plants need? Nitrogen- responsible for growth
Builds proteins and enzymes
Makes up chlorophyll
Phosphorous- helps make seeds and mature, healthy crops
Needed for DNA and RNA
Ensures proper root development
Potassium- a little more indirect, but helps activate plant enzymes
Helps withstand extreme temperatures and pests
Makes more efficient use of water.