Unit 3 AP Biology Flashcards (Topic 3.5 to Topic 3.7)

Define Photosynthesis

Define Photosynthesis

Photosynthesis is the biological process that capture energy from the Sun and produce sugars (Glucose)

How did oxygen form in the atmosphere?

Evidence supports the claim that prokaryotic photosynthesis by organisms such as cyanobacteria, was responsible for the production of oxygen in the atmosphere

Describe the process of light-dependent process? (simple)

Light-dependent reactions capture light energy by using light-absorbing molecules called pigments (chlorophyll is the pigment that absorb light in plants). Pigments used in light-dependent reactions help transform light energy to chemical energy. The chemical energy is temporarily stored in the chemical bonds of carrier molecules, called NADPH. The products of the light-dependent reactions are ATP and NADPH. ATP and NADPH are products that will be used in the Calvin cycle to produce carbohydrates

What are reactants of light-dependent reactions?

H20 + (ADP + P) + NAD+ = ATP + NADPH + O2

Explain how cells capture energy from light and transfer it to biological molecules for storage and use.

During photosynthesis, chlorophylls (embedded in the thylakoid membrane) absorb energy from light, boosting electrons to a higher energy level in photosystems I and II.

What is the net equation for photosynthesis

6H2O + 6CO2 + Light = C6H12O6 + 6O2

What leaves and enter an plants during photosynthesis?

Carbon dioxide enters through stomata and oxygen leave through stomata

Where does photosynthesis and cellular respiration take place?

Chloroplast and Mitochondria

What does Chlorophyll absorb and reflect?

Red, Blue, but reflects green

Where do independent-dependent, and Calvin cycle occur?

Independent-dependent: Thylakoids

Calvin cycle: Stroma

What is the process of the Calvin cycle? (simple)

CO2 reduced into C6H12O6 (Glucose)

NADPH oxidized back into NAD+ and gives it electron away to CO2

ATP convert back into ADP + P to power this process

What are reactants and products of the Calvin cycle?

ATP + NADPH + CO2 = (ADP + P) + C6H12O6 + NADP+

What happens to chlorophyll electrons when light absorption occurs and what is the importance of this?

Electrons will be energized. The energy from the electrons will be used to establish a proton gradient and reduce NADP+ to NADPH

How does electron transport chain play an role in light-dependent reactions?

As the electrons pass through the electron transport chain, protons actively transported across a membrane, establishing a gradient. Protons diffuse through ATP synthase, powering ATP synthesis

Describe the process of light-dependent reaction? (Full)

1. Light participle hits photosystem II P680

2. Electrons are excited in chlorophyll and chlorophyll lose it electrons

3. Electrons flow into electron carrier plastoquinone

4. Since chlorophyll has lost it electrons, it takes electrons from H20

5. H20 turns into ½ O2 + 2H+

6. Plastoquinone transfer it electrons to Cyt bf-6 complex

7. Cyt bf-6 complex begins to pump in H+ (hydrogen ions) from stroma (outside of the thylakoid) into the lumen (inner thylakoid)

8. Thus lumen increased in H+ concentration and stroma decrease

9. Electrons are transfer to plastocyanin and which transfer to photosystem PS I P700

10. The electrons have lost of it energy, but are able to regain energy at PS I P700, upon being stuck by another proton of light

11. Electrons get excited again and go to ferredoxin

12. Carrying the electrons to NADP Reductase

13. Electrons leave and meet up with NADP+ to form NADPH and thus reduce. Reducing H+ in stroma

14. Since there is an buildup of electrons in inner thylakoid. H+ will flow into stroma because of gradient that has formed into ATP synthase that lead to production of ATP

15. ATP + NADPH + O2 are produced at the end

The chlorophyll a special pairs of the two photosystems absorb different wavelengths of light.

The PSII special pair absorbs best at 680 nm, while the PSI special absorbs best at 700 nm. Because of this, the special pairs are called P680 and P700, respectively.

What is the process of CAM? (Full explanation)

1. Carbon fixation happens in advance during the night. Opening it Stomata to receive carbon and some oxygen

2. It opens during the night for it to be used in the day for photosynthesis

3. The molecule oxaloacetate forms into malate

4. During the day, the stomata of the plant is closed

5. Malate is transported into vacculos and then can be transported out. Turned into pyruvate and CO2

6. CO2 powers the calvin cycle for it continue

7. Pyruvate is turned into PEP and the cycle begins again

What is the process of Calvin cycle? (full)

1. 3 Carbon dioxide enter the leave and enzyme Ribulose pick it up

2. Then are transported to form PGA (phosphoglycerate)

3. Energy 6 ATP are used to form 6 ADP

4. 6 NADPH = 6NADH+ + 6H20 + 6Pi

5. After all of these processes 6 PGAL is formed

6. 1 PGAL (a three-carbon sugar used by the cell to produce glucose and other biomolecules)

7. 5 PGAL go make 3 RuBP with the help of 3 ATP = 3 ADP + 3 Pi

8. In order to make one glucose. This cycle must go through 6 turns are to be made

What is photorespiration?

Photorespiration is the process of taking in molecular oxygen (O2) and releasing carbon dioxide (CO2) from organic substances in response to light. Photorespiration is harmful to C3 plants because it reduces plant productivity, which is why it is also known as a wasteful process. It occur at high temperature. Eventually since RuBP has greater affinity for oxygen at higher temperature. There would be no more carbon dioxide with RuBP, since all of it is being released and carbon will run out

What is the process of C4?

1. CO2 enters the plant Stomata and combine with PEP

2. Fixation forms oxaloacetate (4-carbon molecule) and which forms into malate (4-carbon molecule)

3. Malate leaves palisade mesophyll to bundle sealth for Calvin cycle (this process allows Co2 to come into Bundle Sealth for Calvin cycle, but not oxygen. Thus no photorespiration)

4. One carbon from Malate leaves and picked up by rubisco

5. 3 carbon left over are transported to form pyruvate

6. Pyruvate forms PEP with help of ATP and the cycle begins again