Eukaryotic Cell
What is the major difference between a eukaryotic and prokaryotic cell?
Eukaryotic Cells possess membrane bound-organelles
What is cellular metabolism?
Sum of all the reactions that occur in a cell which involve the transfer/usage/production of energy.
What molecule must be present for pyruvate oxidation to occur?
O2
Which part of Cellular Respiration is responsible for the largest amount of ATP production?
Oxidative Phosphorylation
Photosynthesis a (catabolic/anabolic) and (exergonic/endergonic) process.
anabolic; exergonic
Name 5 organelles that are part of the endomembrane system.
Nucleus, Rough ER, Smooth ER, Golgi, Lysosomes, Vacuoles, Peroxisomes
Use the first law of thermodynamics to explain the Proton Motive Force
Electrochemical gradient produces high PE state; chemiosmosis of the protons releases the energy of the gradient; the released energy is used to synthesize ATP
All the Energy is accounted for.
How does glycolysis produce ATP?
What type of reaction allows the TCA to produce high energy electron carriers?
Oxidation
What is the purpose of the light reactions of photosynthesis?
Create ATP and NADH to be utilized in the Calvin Cycle
Which filament in the cytoskeleton would be most prominent in muscle cells?
Microfilaments - responsible for muscle contraction
How does the cell force reactions that are nonspontaneous?
1) Reaction coupling
2) Enzymes
How many net NADH and ATP are produced in glycolysis and pyruvate oxidation. (Assume pyruvate oxidation does not produce FADH2)
Glycolysis: 2 ATP + 2 NADH
Pyruvate Oxidation: 1 NADH x2 per glucose = 2 NADH
Total: 2 ATP + 3 NADH
How many NADH and ATP are produced per glucose molecule in the TCA cycle.
TCA Cycle: 3 NADH + 1 ATP
TCA Cycle x 2 per glucose = 6 NADH + 2 ATP
Rank the following complexes from least electronegative to most electronegative:
PS1, PS2, Cytochrome b6f
PS2, cytochrome b6f, PS1
What three pieces of evidence support the endosymbiont theory of chloroplasts and mitochondria ?
1) They are both double membraned - similar to gram negative bacteria
2) They both contain their own genetic information and specific enzymatic machinery
3) They replicate independently of the cell
1) Organic catalysts = not consumed in the reaction
2) Catalyze only one reaction
3) Stabilize the transition state of a reaction
What is the purpose of fermentation?
Recycle high energy electron carriers; without respiration, NADH and FADH2 would not be oxidized back to NAD+ and FAD+
A researcher is observing the metabolism of a mutant cell. She notices that the normal quantity of high energy electron carriers as well as normal release of water as a byproduct from the ETC. Yet there is a significant deficiency in the amount of ATP produced. What mutation would explain these observations?
Cell has mutant ETC Protein Complexes 1, 3, and 4; these complexes are not pumping protons into the intermembrane space so no proton motive force can be used to produce ATP.
Where does the energy involved in the photosynthesis originate from? How?
Light from the oxidizes a water molecule + energizes the freed electrons; these freed electrons make NADPH and ATP; Energy from NADPH and ATP are stored as sugar
Type 2 diabetes is often called insulin-independent diabetes as despite production of insulin, blood sugar levels are not maintained properly. This is often due to the insulin protein being mutant or abnormal. Based on your understanding of the eukaryotic cell, which organelle(s) could be responsible for this abnormal insulin?
2) Rough ER: incorrect translation of mRNA
3) Golgi Apparatus: incorrect packaging and/or post-translational modifications
Explain how ATP is used to power endergonic reactions.
2)Hydrolyzing ATP reduces that PE and converts it to usable energy for the reaction
(Some reactions involve phosphorylation of the substrate - this raises the energy of the reactant to above the product and produces a favorable reaction)
A researcher is observing the metabolism of a mutant cell. He observes that despite normal glycolysis occurring and the presence of O2, the cell does not progress to the TCA cycle. He further observes that all the enzymes involved in the TCA cycle are normal as well. Explain the mutation that could cause this observation.
1) Inability to oxidize pyruvate
2) Mutant Coenzyme A
Explain, in detail, how an FADH2 molecule is used to produce ATP
1) FADH2 produced either in pyruvate oxidation or TCA cycle
2) FADH2 releases its proteins to ETC Protein Complex 2
3) The electrons travel from complex 2 to complex 3 to complex 4
4) Complex 3 and 4 pump protons into the intermembrane space
5) ATP synthase uses the electrochemical gradient generated by these protons to synthesize ATP - Proton Motive Force
A mutant plant is unable to synthesize sugar efficiently. In the lab it is observed that this plant has a deficiency of high energy electron carriers resulting in poor yield from the Calvin Cycle. Propose where and what the mutation, in the Light Reactions, is.
1) Plant is unable to oxidize water properly
2) Plant has mutant PS2/PS1 in which electrons are not released/properly replaced
3) Plant has mutant NADP+ so it is difficult to produce NADPH