1. Energy in a Cell ATP: Energy in a Molecule
Photosynthesis: Trapping Energy
Cellular Respiration: Getting Energy to Make ATP

2. ATP: Energy in a Molecule
Cell energy
Organisms and their cells need an endless supply of energy in order to function
Energy to walk, talk, bend, exercise
Cells get energy from the food you eat
Organisms break down food into small nutrient molecules that can enter your bloodstream
Cells then break down the food molecules
Cells use some of the ATP from the food molecules, then store the rest

3. ATP: Energy in a Molecule
ATP is known as the cell’s “money”
Cells must have plenty of ATP “money” to spend whenever the cell needs to work
Without a constant supply of ATP, the cell will die
Cells use to ATP for many things
make ribosomes
help with cell division
for active transport
Maintain homeostasis

4. The ATP molecule

5. ATP: Energy in a Molecule
Forming and breaking down ATP
Cells store energy by adding a phosphate group to a ADP
ADP + P  ATP (energy)
Adenosine diphosphate  adenosine triphosphate
When cells use energy, the process works in reverse
ATP  ADP + P (energy is released)
The process is then ready to start all over again

6. Redox Reactions
Most of the important energy changes in organisms involve chemical reactions known as oxidation reduction reactions.
Photosynthesis & cellular respiration are oxidation reduction reactions.

7. Oxidation Involves the : Releases Energy Combining with Oxygen
Loss of Electrons
Loss of Hydrogen

8. Reduction Involves the: Absorption of Energy Separation from Oxygen
Gain of Electrons
Gain of Hydrogen

9. LEO the Lion goes GER Loss of Electrons is Oxidation
Gain of Electrons is Reduction

10. Photosynthesis: Trapping Energy
Autotrophs/the producers of the planet
Autotrophs are organisms that can make their own food (plants)
Autotrophs make their own food through the process of photosynthesis
They make simple sugars that other organisms can break down into ATP
Autotrophs trap energy from sunlight and use the energy to build carbohydrates (sugars)

11. Photosynthesis: Trapping Energy
The green pigment chlorophyll absorbs sunlight
Found in the chloroplasts
Plants also have other colored pigments that help trap sunlight
These pigments give plants their bright colors

12. Chlorophyll

13. Photosynthesis
The process by which plants use light energy to make food molecules from CO2 & H2O

15. Larry the Sun Light Reaction H+ Light O2- H2O ATP
chlorophyll zapped within chloroplast
H2O
ATP
Light Reaction

16. Calvin the Moon Calvin Cycle (Dark Reaction) CO2
glucose or C6H12O6 or sugar H+
ATP
(from light reaction)
(Dark Reaction)
Calvin Cycle

18. Photosynthesis: Trapping Energy
Photosynthesis: the basic steps
1st step – chloroplasts trap sunlight
2nd step – light energy is converted to chemical energy (sugar) and then stored
Water and carbon dioxide are also required for this step
The general equation for photosynthesis is:
6CO2 + 6H2O + light energy  C6H12O6 + 6O2
carbon dioxide plus water plus light produces sugar and oxygen (in the presence of chlorophyll)

19. Photosynthesis: Trapping Energy
There are 2 main groups of reactions that take place during photosynthesis
Light reactions
Calvin cycle (formerly called the dark reaction)
Light reactions occur when light energy is converted to chemical energy
This is the photo part of photosynthesis
These reactions split water molecules and provide the energy for the Calvin cycle

20. Photosynthesis: Trapping Energy
The Calvin cycle
The series of reactions that form simple sugars using carbon dioxide and hydrogen (from water)
The Calvin cycle is the synthesis part of photosynthesis

21. Photosynthesis: Trapping Energy
The Light Reactions
Light strikes chlorophyll
Electrons gain energy and jump out of chlorophyll
The electrons move down the electron transport chain
The electrons give off energy, which is used to make ATP
Electrons from water move to the chlorophyll, to replace the lost electrons

22. Photosynthesis: Trapping Energy
The Light Reactions
Water breaks up into hydrogen and oxygen
Light causes the electrons to gain energy and leave the chlorophyll again
Electrons and hydrogen are added to NADP+, which produces NADPH + H+
The ATP made in the light reactions will be used in the 2nd stage of photosynthesis – the Calvin cycle

23. Electron transport chain

24. Photosynthesis: Trapping Energy
The Calvin Cycle
This is a complex chemical reaction that uses ATP to make simple sugars
A 5 carbon sugar is formed
It breaks into two 3 carbon sugars
The two 3 carbon sugars go through some chemical reactions and finally make a 5 carbon sugar
The process starts again when a carbon from CO2 is used to turn the 5 carbon sugar into a 6 carbon sugar
This is called carbon fixation

25. The Calvin Cycle

26. Photosynthesis: Trapping Energy/Locations
Overview :Light reaction and Calvin cycle
Light reactions take place in the thylakoids
The Calvin cycle takes place in the stroma
The light reactions make the ATP that is used to make sugar (food) during the Calvin cycle
Animals then eat the sugars to get energy they need to survive & thrive

29. Now….Add the Photosystems
(PSII) Light is absorbed by ?? or other pigments in photosystem II. This E from ?? is then transferred to electrons which are then passed down the ??. Separately enzymes break apart ?? Into electrons & of ?? Ions & ??.
(ETC) Electrons from ?? move though the ETC to photosystem I. E from this process are used to transport ?? ions from the stroma into the inner ??.
(PSI) As in PSI, pigments add E from light to the electrons. The high E electrons are then picked up by NADP+ to form ??.

30. And then…
d) (H ion movement) The inside of the ?? fills with H + ions, giving the membrane an overall charge. The difference in charges provides the E to make ATP.
e) (ATP formation) A protein called ??? allows the H ions to pass through & it rotates (like a turbine with water running over it at a hydroelectric power plant). As this happens the protein binds ADP & PO4 to produce ???.

31. Photosynthesis: Trapping Energy
Life without light
Some organisms are able to energy without sunlight
Mainly bacteria
They are chemosynthetic – they are autotrophs that can use different chemicals to produce methane
These types of bacteria live near deep cracks in the ocean floor

32. Chemosynthetic vent worms