Bio Help! Quick plant cell question:

[Rook]

Where is all the plant cell's ATP? and Energy producing material?
Thylakoid space? Thylakoid membrane? Chloroplasts?

Thanks!!

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[Futureortho24]

Where is all the plant cell's ATP? and Energy producing material?
Thylakoid space? Thylakoid membrane? Chloroplasts?

Thanks!!

If I recall correctly, ATP is synthesized via the Light Reaction & the Light Reaction occurs in the Thylakoid Membrane. The Thylakoid Membrane is part of the chloroplast - does that help at all?!!

 

[teefie]

If I recall correctly, ATP is synthesized via the Light Reaction & the Light Reaction occurs in the Thylakoid Membrane. The Thylakoid Membrane is part of the chloroplast - does that help at all?!!

Dont forget they might want you to know that light reaction takes place in the grana, which are stacks of thylakoid disk, and dark reactions take place in the stroma which is the fluid surrounding these grana in the chloroplasts.

 

[Rook]

Dont forget they might want you to know that light reaction takes place in the grana, which are stacks of thylakoid disk, and dark reactions take place in the stroma which is the fluid surrounding these grana in the chloroplasts.

Thanks for the replies!

So let me get this straight:
Photosynthesis => Choloroplasts=> Grana=> In Thylakoid membrane
Dark rxn=> Cholorplasts=> stroma (fluid matrix of cholorplast outside of grana0

Right?

 

[L8DYV]

Where is all the plant cell's ATP? and Energy producing material?
Thylakoid space? Thylakoid membrane? Chloroplasts?

Thanks!!

The ATP is produced as a result of the proton motor force that occurs between the thylakoid lumen and stroma, seperated by the thylakoid membrane. Protons (from oxidation of H2O in photosyntheisis II) are pumped via electron carriers from the stroma, through the thylakoid membrane to the thylakoid lumen against their concentration gradient, where they will accumulate in the lumen and can subsequently be used to power the ATP synthase complex to produce ATP from ADP and Pi.

Hopefully this helps.

 

[Hannamsm]

A. Light Reactions (photolysis) (in grana)
a. Begins with absorption of light by chlorophyll molecule (Light strikes the special chlorophyll a P700 molecule in photosystem I, it excites electrons to a higher energy level).
b. The excited electron of the chlorophyll can flow along 2 pathways
c. Cyclic Electron Flow
i. The excited electron of P700 move along a chain of electron carriers
ii. Via a series of redox reaction, electron eventually goes back to P700
iii. Produces ATP in the process called cyclic photophosphorylation
iv. Uses a coenzyme carrier called ferrodoxin, an early electron carrier in this chain
d. Noncyclic electron flow
i. Key pathway of the light reaction and involves both photosystems
ii. Instead of electron returning to P700, it goes to electron acceptor NADP+.
- P700 is left with electron "holes" and thus is a powerful oxidizing agent
iii. When light strikes P680 in photosystem 2, electrons are excited again.
- The electrons follow same electron carrier chain as cyclic and fill the holes in the P700 (producing ATP by noncyclic photophosphorylation)
- Now P680 has holes and is strong enough to oxidize water and fill its holes.
- Water is split into two hydrogen ions and oxygen atom.
a. Oxygen combine to form O2 (electrons produced reduce P680).
iv. The net result is the production of NADPH and ATP and photolysis (break down) of water, releasing oxygen.
B. Chemical Aspects of Photosynthesis
a. Oxygen produced in photosynthesis comes from water, not carbon dioxide. (Research used radioactive isotopes such as O-18 and C-14).
b. Photoionization - escape of high energy electrons from chlorophyll
C. The Dark Reaction (in stroma)
a. Uses ATP and NADPH from light reactions to reduce CO2 to carbohydrate
b. Although doesn't directly require light, it only happens during day b/c of need for ATP and NADPH
c. Also called calvin cycle, carbon-fixation/reduction synthesis
d. Product of the cycle is three carbon sugar Phosphoglyceraldehyde (PGAL)
i. Cycle must take place three times to make 3 carbon sugar
e. Cycle begins with CO2 added to ribulous biphosphate (five carbon sugar)
i. This produces 6-carbon intermediate (unstable)
ii. Immediately splits into two 3-carbon molecules
1. 3 carbon molecules called 3-phosphoglyceric acid
2. Acid is phosphorylated by ATP, reduced by NADPH to give glyceraldehyde 3-phosphate (PGAL)
3. 2 PGAL converted to glucose (which can later be oxidized to produce energy)

 

[Rook]

A. Light Reactions (photolysis) (in grana)
a. Begins with absorption of light by chlorophyll molecule (Light strikes the special chlorophyll a P700 molecule in photosystem I, it excites electrons to a higher energy level).
b. The excited electron of the chlorophyll can flow along 2 pathways
c. Cyclic Electron Flow
i. The excited electron of P700 move along a chain of electron carriers
ii. Via a series of redox reaction, electron eventually goes back to P700
iii. Produces ATP in the process called cyclic photophosphorylation
iv. Uses a coenzyme carrier called ferrodoxin, an early electron carrier in this chain
d. Noncyclic electron flow
i. Key pathway of the light reaction and involves both photosystems
ii. Instead of electron returning to P700, it goes to electron acceptor NADP+.
- P700 is left with electron "holes" and thus is a powerful oxidizing agent
iii. When light strikes P680 in photosystem 2, electrons are excited again.
- The electrons follow same electron carrier chain as cyclic and fill the holes in the P700 (producing ATP by noncyclic photophosphorylation)
- Now P680 has holes and is strong enough to oxidize water and fill its holes.
- Water is split into two hydrogen ions and oxygen atom.
a. Oxygen combine to form O2 (electrons produced reduce P680).
iv. The net result is the production of NADPH and ATP and photolysis (break down) of water, releasing oxygen.
B. Chemical Aspects of Photosynthesis
a. Oxygen produced in photosynthesis comes from water, not carbon dioxide. (Research used radioactive isotopes such as O-18 and C-14).
b. Photoionization - escape of high energy electrons from chlorophyll
C. The Dark Reaction (in stroma)
a. Uses ATP and NADPH from light reactions to reduce CO2 to carbohydrate
b. Although doesn't directly require light, it only happens during day b/c of need for ATP and NADPH
c. Also called calvin cycle, carbon-fixation/reduction synthesis
d. Product of the cycle is three carbon sugar Phosphoglyceraldehyde (PGAL)
i. Cycle must take place three times to make 3 carbon sugar
e. Cycle begins with CO2 added to ribulous biphosphate (five carbon sugar)
i. This produces 6-carbon intermediate (unstable)
ii. Immediately splits into two 3-carbon molecules
1. 3 carbon molecules called 3-phosphoglyceric acid
2. Acid is phosphorylated by ATP, reduced by NADPH to give glyceraldehyde 3-phosphate (PGAL)
3. 2 PGAL converted to glucose (which can later be oxidized to produce energy)

Wow, you guys are great!!
Really cleared things up!