1. Chapters 8 & 9 Photosynthesis & Cellular Respiration
Regular Biology
Waggy

2. Photosynthesis Objectives
Describe the role of chlorophyll in photosynthesis
Summarize the main events of the steps of photosynthesis & the Calvin cycle
Explain how ATP is formed during photosynthesis
Explain how environmental factors influence photosynthesis

3. Photosynthesis Is the most valuable biological system on the planet!
Simply put, photosynthesis is the process by which plants combine sunlight, carbon dioxide, and water to create sugars (carbohydrates)
Plants are the ONLY living thing on earth that can convert the suns energy into a usable form

4. Living organisms that can make their own food are called autotrophs
Autotrophs are typically the first step in the food chain because of this ability
There are two parts to photosynthesis:
1. Light reactions: PSII & PSI
2. Calvin cycle

5. STEP 1: Light Reactions Plant cells contain chloroplasts
Chloroplasts are cell organelles that contain chlorophyll
Chlorophyll is a green pigment & is kept in coin shaped structures called thylakoids (they look like a stack of coins)

6. Photosystem II (PSII) sunlight strikes the chlorophyll & is absorbed
The extra energy from the sun causes an electron to be released from the chlorophyll molecule
This excited electron jumps from the chlorophyll molecule & is caught by the primary electron acceptor

7. The electron (e-) is now sent through an electron transport chain until it reaches a chlorophyll molecule in Photosystem I (PSI)
The electron replaces the missing e- in PSI.

8. SUNLIGHT
PSII
Hydrolysis
Chlorophyll
Gives up e-
Excited
e- jumps
e- is caught
by e- acceptor
e- transport
chain
e- replaces
one lost in PSI

9. Photosystem I (PSI)
Chlorophyll in PSI is struck by sunlight & an e- becomes excited
The e- is caught by another primary e- acceptor
Now the e- moves through a second electron transport chain
At the end of the second transport chain, the e- combines with H+ to form a Hydrogen atom

10. This Hydrogen atom attaches to a NADP molecule creating NADPH
NADPH is a form of energy like ATP
NADP: nicotinamide adenine dinucleotide phosphate
ATP: adenosine triphosphate

11. SUNLIGHT
PSII
PSI
Hydrolysis
Chlorophyll
Gives up e-
Chlorophyll
Gives up e-
Excited
e- jumps
Excited
e- jumps
e- is caught
by e- acceptor
e- is caught
by e- acceptor
e- transport
chain
e- transport
chain
NADPH
formed
e- replaces
one lost in PSI

12. The Production of ATP:
ATP is also produced in the thylakoid membrane in a process called chemiosmosis