Download 11/6/11 10:49 PM Metabolism Poster Questions: Answer the

11/6/11 10:49 PM
Metabolism Poster Questions:
Answer the following questions concerning respiration.
1. Consider the mitochondrial electron transport chain.
a. How many hydrogen ions can be pumped for every NADH?
3
b. How many hydrogen ions can be pumped for every FADH2?
2
2. How many ATP’s can be generated for each hydrogen ion that flows
through the ATP
synthase?
1
3. One NADH is the equivalent of how many ATP’s?
3
4. One FADH2 is the equivalent of how many ATP’s?
2
5. GTP is also made in respiration. How many ATP’s can be made from a
GTP?
1 GTP= 1 ATP
6. Fill in the table below: (for 1 glucose)
Process Location #ATP #GTP #NADH #FADH2 Total equivalent ATP
Glycolysis cytosol 2
0
2
0
8
Pyruvate
Oxidation matrix
Krebs Cycle
0
Matrix 0
Total ATP = 38
0
2
2
0
6
6
2
24
7. How many total ATP can be made? Why is this sometimes a different
number? 38
different number because use energy, reenergize NADH, FAD-NADH
transporter
8. What drives the ATP synthase?
Hydrogen Gradient
9. What is the significance of the folding of the inner mitochondrial
membrane into crystae?
Increase the surface area
10. In the electron transport chain, why doesn’t FADH2 release its electrons
to the same acceptor as NADH?
FADH2 has a higher electronegativity
It can’t give its electrons to the same acceptor as NADH
11. Electrons passing through proteins imbedded in membranes are not
influenced by gravity.
In what sense are electrons flowing “downhill”?
Going towards Gibb’s free energy
12. Where do the hydrogen ions that are pumped across the membrane by
the electron transport system come from?
Water
13. Describe what happens to the electron transport chain when there is no
oxygen present.
ETC shuts down because it is full of electrons
Then it must do fermentation
14. What is the purpose of fermentation? Why can’t the cell simply produce
pyruvate and excrete it?
Purpose is to regenerate NAD+
15. Describe what happens in the “investment phase” of glycolysis. What is
the purpose of this investment?
Phosphorylative glucose primes it to react (pushes it up hill)
16. Describe what happens in the energy harvesting phase of glycolysis.
G3P  Pyruvate
NAD+  NADH
ATP Produce
17. In terms of enzyme regulation, describe what happens when the cell has
plenty of energy.
What molecules are in abundance and what enzymes do they affect?
? Lot of ATP & NADH
Inhibit PFH
18. Describe the processes that generate carbon dioxide.
Alcoholic fermentation
-Krebs cycle, pyruvate oxidation, photorespiration
(ETC does not generate CO2)
19. Explain where oxygen is used and what its function is.
Used in end of ETC in the mitochondria
the final electron acceptor (trash can)
20. Describe the advantage of separating these processes into different
compartments.
More efficient, less interference
21. Compare the energy produced by oxidation of a 6-carbon fatty acid with
the 6-carbon
glucose molecule
-6 carbon fatty acid must be processed more because it needs more energy
22. The Atkins diet works by creating a deficit of carbohydrates. Where in
the system do
carbohydrates enter?
Enter glycolysis (beginning)
23. In terms of metabolic pathways, why is it OK to eat fat on the Atkins
diet?
Provides more energy then carbs
Atkins diet  very few carbs
24. Glycolysis is thought to be the most ancient of the metabolic pathways
we have studied.
Explain why it is thought to have evolved first.
-doesn’t require special compartments because it happens in the cytoplasm
-doesn’t need O2
-Everyone does it
25. The mitochondrion is thought to have evolved by endosymbiosis.
Explain what endosymbiosis is and describe evidence that supports the
theory.
-when something lives inside of another organism
-multiple membranes, double membrane
-prokaryotic chromosome
-separate by binary fission
-ribosomes are like bacterial ribosomes
-works on operons
26. Our posters did not explore the catabolism of proteins. Where do amino
acids enter the process?
-allows for two-carbon reactions
27. Where do the materials for anabolism of fats, proteins and
carbohydrates come from?
?
28. What is light?
A form of electromagnetic energy that has wave-like properties and travels
in bundles called photons
29. How do photosystems I and II differ?
II has oxygen evolving complex
I does not, it received electrons from ?
II & I transfer to ferradoxin to make NADPH. I can absorb higher
wavelengths of light
680 – II – higher energy
700 - I – lower energy
30. What enables these photosystems to absorb and use light other than
that of exactly 700 and 680 nm? Explain how this works.
Pigments absorb different wavelengths
light is composed of photons
a photon is a packet of energy, a particle of light
31. After an electron is removed from the chlorophyll a molecule in the
photosystem, how is it replaced in photosystem I and in photosystem II?
Photosystem II: Oxygen evolving complex steals an electron from water,
replenishing the electron and creating oxygen
I: gets it from P.S. II or itself, cyclic electron transport
32. Describe what each photosystem uses and what it generates.
They are functional and structural units of protein complexes involved in
photosynthesis that together carryout the primary photochemistry of
photosynthesis: the absorption of light and transfer for energy and electrons
found in the thylakoid membrane
I uses light, electron from up chain generates electron
NADP+  NADPH
II uses water generates O2, and pulls pair of electron, generates high
energy pair of electrons
33. Describe the difference between the z scheme (noncyclic
photophosphorylation) and cyclic photophosphorylation
z-scheme is linear, produces NADPH, ATP, O2
Cyclic produces O2
34. Where do the hydrogen ions that are pumped across the membrane by
the photosynthetic electron transport chain come from?
Water molecules
35. Are the electrons passing through proteins embedded in the thylakoid
membrane flowing ‘downhill’ as in the inner mitochondrial membrane.
Explain how both yes and no are correct answers.
Yes because its downhill  low to high energy
No because shot back up by light which raises it (uphill)
36. Explain where oxygen is generated and what its function is.
-OEC
-to provide electrons
-oxygen is supposed to be a waste product
37. Why are the reactions of the photosynthetic electron transport system
sometimes referred to as the “light reactions?”
Require light energy to energize it
(Calvin Cycle does not happen in the dark)
38. What is the direct source of energy for the ATP synthase in the thylakoid
membrane?
Compare this with the mitochondrial membrane.
Hydrogen Gradient
exact same thing as mitochondrial membrane
mitochondria evolved from the chloroplast
39. List the starting materials and end products of the Calvin Cycle. Hint—it
is not glucose.
Start: CO2, RUBP, NADPH, ATP
Products: G3P, RUBP (cycle)
(rusbisco doe not get used up because its an enzyme)
40. For one sucrose (C12H22O11), how many turns of the Calvin Cycle are
necessary?
12
3 turns make 1 G3P, need 4 G3P to make sucrose = 12 turns
41. For one sucrose molecule, how many ATP’s are used? How many
NADPH’s?
3 ATPs per turn
Fixation-Reduction-Regeneration
Each carbon 9 ATPs
54 ATPs to make glucose. You get 32 when you break it down
42. In what compartment does the Calvin Cycle take place?
Stroma
43. The Calvin Cycle is sometimes referred to as the “Dark Reactions of
Photosynthesis”. Why is this a misleading term?
Needs light not dark, the Calvin Cycle does not happen in the dark
44. How is Rubisco activity regulated?
Light activated
45. What is photorespiration and why is it considered to be a “slipping of the
gears?”
Photorespiration interferes with efficiency of the calvin cycle
buildup O2
3 carbon & 2 carbon compound detox into CO2
46. Explain how C4 and CAM plants avoid photorespiration.
Structure
C4 plants pump CO2
CAM ½ day, ½ night
Stomata closes and opens
47. Describe the interaction between temperature and concentrations of CO2
and O2 inside a
plant leaf.
O2 goes up when the temperature goes up and CO2 goes down (stomata
closes during the day O2 cannot be released, CO2 cannot come in)
48. Global atmospheric CO2 levels and temperature are rising. What impact
might each of
these have on the different types of metabolism (C3, C4, and CAM that
plants do)?
Temperature goes up, more photorespiration
C3 benefits most from CO2 up
CAM benefits most from temperature up
49. Since metabolism consists of an inter-related series of chemical
reactions and must also have evolved, classify the metabolic processes of
glycolysis, fermentation, fatty acid metabolism and respiration into more
ancestral and more derived pathways. Since evolution frequently re-uses
old structures in new ways, are there any pathways that seem related?
1. Glycolysis and fermentation (need each other)
2. photosynthesis
3. respiration
4. fatty acid metabolism
50. Compare the inner mitochondrial membrane with the thylakoid
membrane of the chloroplast. Do the similarities suggest an evolutionary
relationship?
Cyclic came first because only 1 photosystem was used
51. Humans often make the mistake of thinking that we are the most
complex organisms.
Photoautotrophs such as plants and algae are necessarily more metabolically
complex.
Explain why this is so.
Can’t eat things so they must make themselves, like 8 essential AA need
them to make proteins
plants have cellular respiration and photosynthesis and glycolysis to make
secondary compounds because they cannot move
we do glycolysis and cellular respiration because we can get our own food,
we don’t have to make it.
11/6/11 10:49 PM
11/6/11 10:49 PM