TCA Cycle
Where does the TCA cycle take place?
mitochondrial matrix
Where does the ETC occur?
Cristae of mitochondria
What type of pigments are responsible for light absorption?
antenna pigments.They do not directly participate in conversion of light energy.
What is the difference between the Outer and inner membranes of the chloroplast?
outer membrane has porins, making it permeable to large molecules.
Inner membrane is continuous with thylakoid and contains light-absorbing pigments, electrons carriers, and ATP-synthesizing enzymes
What is respiration?
-reduce O2 to form H2O
-removes high energy electron from reduced organic substrates to form ATP and NADH
What generates the acetyl-CoA used in the TCA cycle?
fermentation process of pyruvate, after it is produced in glycolysis
Define Proton Motive Force.
electrogenic, pH and charge gradients, used to drive ATP synthase
Where do the light dependent reactions of photosynthesis take place and what do they generate?
On the Thylakoid membrane, liberates O2, and generates NADH and ATP using light energy and glucose
Where do the ATP and NADPH used in the Calvin cycle come from?
From light-dependent reactions of photosynthesis
Why don't all cells use the method of CAM or C4 Plants?
Energetic cost. Although it is lower than not generating food and the plant dying.
What is the pathway of a molecule from the cytosol to the mitochondrial matrix?
1. cytosol
2. outer mitochondrial membrane
3. inner membrane space
4. inner mitochondrial membrane
5. mitochondrial matrix
What is the function of inhibitors of the ETC?
stop electron transport, which stops cellular respiration.
No ETC, no proton gradient to drive ATP Synthase
What are the differences between Photosystem I and Photosystem II?
Photosystem I absorbs light at 680 nm, PSII absorbs at 700nm. LHCII is used for PS II, LHCI is used for PSI. PSI can participate in cyclic photophosphorylation and noncyclic. PSII only participates in noncyclic.
What is the main input the Calvin cycle?
6 CO2 needs 1 6-carbon sugar, 12 NADPH, and 18 ATP
What is photorespiration? What are the steps?
rubisco accepts O2 as substrate and fixes it, rather than CO2.
in high temperatures, Rubisco's O2 affinity increases
1. 2-PGlycolate and 3-PGlycerate created
2. converted to glycine
3.converted to serine, CO2, and NH3
4. Converted to glycerate
5. ATP converted to ADP and 3PG
6. converted to RuBP
What is the overall reaction of the TCA cycle?
2 acetyl CoAs converted to 6 NADH, 6 protons, 2 FADH2, 2 ATP
What are the steps of electron transport starting with both reducing agents and including ATP synthase?
NADH:
1. Complex I accepts electron from NADH, 1 proton moves from matrix to IMS
2. electron accepted by lipid soluble coenzyme Q
3. electron accepted by complex III, 2 Protons move into IMS
4. Cytochrome C, a soluble protein, accepts electron
5. Complex IV accepts proton, 3 protons move into IMS
6. O2 accepts electron and is converted to H20
6. Proton gradient drives ATP synthesis through F1F0 ATP Synthase
FADH2:
1. Complex II accepts electron from FADH2
2. Coenzyme Q accepts electron from complex II
3-6. same as aboveWhat is are the purposes of chlorophyll a and b? carotenoids?
chlorophyll a and b absorb blue and red light. Carotenoids absorb green light, resulting in orange and red leaves.
After the Calvin cycle, what is the function of GAP?
exported to the cytosol in exchange for phosphate ions and is used to synthesize sucrose in stroma. If it remains in chloroplast it will become startch
What are the steps of respiration in CAM plants?
1. During the night, CO2 from environment combines with PEP carboxylase to become oxaloacetate
2. oxaloacetate converted to malate or organic acids
3. During the day malate or organic acids decarboxylated to pyruvate
4. CO2 goes into Calvin cycle
4. pyruvate converts to PEP during the day
5. PEP becomes PEP carboxylase
6. Cycle continues
What are the steps of the TCA/ Krebs cycle? (draw if easier)
1. 2 Acetyl-CoAs from fermentation combine with oxaloacetate to form citrate
2. CO2 is released, NAD+ is oxidized to NADH + H+, and citrate becomes alpha ketoglutarate
3. NAD+ Oxidized to NADH + H+, ATP and CO2 are released, and alpha ketoglutarate becomes succinate
4. FAD oxidized to FADH2, succinate becomes fumarate
5. fumarate becomes malate
6. NAD+ oxidized to HADH + H+, and malate becomes oxaloacetate
7. Cycle repeats
What are the 5 main components of aerobic respiration energy production, and how many ATP molecules are produced in each?
1. Glycolysis= 6 or 8 ATP
2. Fermentation= 6 ATP
3. Krebs cycle= 2 ATP + 18 with NADH, 4 with FADH2
4. ETC= O2 to H2O and creates proton gradient for ATP synthase
5. ATP synthase= MANY ATP
*total without ATP Synthase= 36 or 38
What are the steps of the light-dependent reaction of photosynthesis? (draw it out if that is easier)
1. water is hydrolyzed and allows PSII to an accept electron and become excited P680
2.Phenophytin is a high energy electron acceptor that passes the electron down the redox chain to PQ
3. PQ accepts electron and proton from stroll side to PQH2
4. PQH2 is oxidized and passes electron to cytochrome b6f, where the proton enters the thylakoid lime
5. Oxygen is released to environment. Protons retained in thylakoid lumen and contribute to proton gradient
6. PSI absorbs the light producing p670+ and the electron is transferred from PSII through FD to NADP
7. reduction of NADP+ to NADPH is catalyzed by FD-NADP+ reductase
8. ATP synthase uses proton gradient and produces ATP (4 protons= 1 ATP)
What are the steps of the Calvin Cycle?
1. 6 CO2 with 6 RuBP and rubisco to 6 carboxylase intermediate
2. carboxylase splits to 12 PGA
3. 12 ATP dephosphorylated to 12 ADP, PGA converter to 12 BPG
4. 12 NADPH to 12 NADP+ and 12 BPG converted to 12 GAP
5. 2 GAP converted to fructose then to sucrose
5. 10 GAP and 6 ATP converted to 6 ADP and 6 RuBP
6. cycle is repeated
1. CO2 comes in to mesophyll cells and with PEP carboxylase becomes oxaloacetate
2. Oxaloacetate converted to malate
3. malate moves into bundle sheath cells
4. malate decarboxylated to pyruvate
5. CO2 goes into Calvin cycle, pyruvate moves into mesophyll cells
6. ATP converted to AMP and pyruvate converted to PEP
7. PEP becomes PEP carboxylase
8. Cycle repeats