Quiz 14 Review Flashcards
1
Q
How are ATP formed?
A
Electron transport system –> phosphorylated ADP (doesn’t have to be in electron transport so mainly just phosphorylation of ADP)
2
Q
From which part of the mitochondria do NAD and FAD get pumped from and where are they pumped to?
A
During electron transport, H+ are taken up and accumulate in the intermembrane. Once the concentration of H+ is greater than the mitochondria matrix the are pumped from the intermembrane to the mitochondrial matrix.
3
Q
What is the purpose of the TCA cycle as defined in class?
A
a. The oxidation of Acetyl-CoA
4
Q
De novo synthesis of fatty acids in the fat cell starts with acetyl-CoA. Contrast the steer and market hog above in how the fat cell gets the acetyl-CoA.
A
-
Ruminants (cow)
- ferment dietary glucose to VFA, principally acetate
- derived acetate is converted to acetyl-CoA in cytosol of fat cells which can directly enter fatty acid biosynthesis
- ferment dietary glucose to VFA, principally acetate
-
pig-
- absorb their glucose
- glycolysis produces pyruvate in cytosol; the acetyl-CoA is generated in the mitochondrea
- acetyl Co-A in mitochondria then shuttled out to form citrate
5
Q
The TCA cycle occurs in the cytosol. True or False? If false, what cellular compartment should it be?
A
a. In eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion
6
Q
In which cellular organelle does the electron transport system function?
A
Mitochondria
7
Q
Now that the fat acids from the diet and from de novo synthesis are stored in the fat cells as TAG, they are available for the animal to use in the event of feed restriction and fasting. Moving the fatty acids out of the fat cell is referred to as “mobilization of fatty acids” and involves more lipases. What are the three lipases involved in this process that occurs in the fat cell?
A
- Mobilization of FA lipases:
- Adipose Triglyceride Lipase
- Hormone-Sensitive Lipase
- MAG Lipase
8
Q
How does diabetes affect metabolism in liver cell
A
Insulin decreases.
Nutrient availability is high, but cells cannot respond without insulin.
Liver cell:
- Gluconeogenesis increases: blood glucose increases.
- B-oxidation increases.
- Ketone production increases (50-100 fold).
- Blood pH decreases: ketoacidosis occurs.
9
Q
What is the purpose of the TCA cycle?
A
Oxidation of Acetyl- CoA
10
Q
Define its purpose -what is produced by each cycle?
- fatty acid oxidation
A
To produce acetyl CoA, NADH, and FADH2
11
Q
What is pyruvate converted to that starts the TCA cycle?
A
a. The first reaction occurs from condensation of acetyl-CoA with oxaloacetate to form citrate
12
Q
What is produced for a Fatty acid with a given number of C-atoms:
A
10 C/2=5 C, and 5 Acetyl- CoA
5-1=4
4 NADH
4 FADH2
13
Q
Wha is the purpose, as stated in class on the slides used to illustrate this process, of this reaction sequence? Also, in what part of the cell will this reaction sequence take place?
A
- purpose of b-oxidation:
- produce acetyl-CoA
- NADH
- FADH2
14
Q
The fatty acids in #16 will be transported through the blood as free fatty acids and will be taken up by cells, such as muscle cells, cardiac muscle cells, and other, for use as a substrate for ATP generation. What is the first reaction that occurs involving fatty acids (carboxylic acids) that is commonly referred to as “fatty acid activation”?
A
- converts the carboxyl to the CoA-thioester
- Defined:
- The addition of CoA to the fatty acid that prepares the fatty acid for further metabolism.
15
Q
What else is produced as part of this process that will be used later in ATP production?
A
NADH
16
Q
How many ATP can be produced by the interaction of one FADH2 with the electron transport system?
A
2 ATP are possible
17
Q
Even though one NADH is produced during glycolysis, this NADH is not going to result in production of the same number of ATP that NADH that occurs from the TCA cycle will. Why is this?
A
Because NADH does not freely move from the cytosol to the mitochondria
18
Q
In a fasted animal how is metabolism characterized in fat cells
A
Insulin decreases.
Catecholamine effectiveness increases.
Fat cell:
- Catecholamines increase: cAMP increases: Protein kinase increases: HSL activity increases: fatty acid hydrolysis increases.
- Glycerolipid biosynthesis decreases.
- ACC activity decreases: fatty acid synthesis decreases.
- LPL activity decreases = Fatty acid release from cells increases.
- Glycerol release increases: transported to liver for gluconeogenesis.
19
Q
For a fatty acid that contains 6 carbons, what and how many of what is produced (that will be used in the overall process for ATP production will occur when this fatty acid is completely oxidized? (Know how to solve, as there will be different C # given)
A
- Split C# in 1/2= # of Acetyl-CoA–> subtract 1 from this number to get FADH2 and NADH #’s
-
Produces 3 Acetyl-CoA and 2 FADH2 and 2 NADH
- acetyl CoA# x10
- for each FADH2, two ATP are produced
- for each NADH, three ATP are produced
- SO multiply it out.
- (3x10)+(2x2)+(2x3)= 40ATP
20
Q
How much ATP from the complete oxidation of a single glucose molecule is possible?
A
36 ATP
21
Q
How many ATP can be produced by the interaction of one NADH with the electron transport system?
A
3 ATP are possible
22
Q
What molecule serves as the terminal electron acceptor of the electron transport system?
A
Oxygen
23
Q
In addition to the NADH that occurs from glycolysis, what general reactions or cycles will result in production of the remaining NADH associated with the complete oxidation of glucose?
A
TCA (Tri Carboxylic Acid) Cycle
24
Q
How many ATP possible in fatty acid oxidation?
A
Depends on the number of H in each fatty acid
25
What molecule that occurs in de novo synthesis of fatty acids in the fat cell will regulate fatty acid oxidation when this molecule is produced in the muscle cell? Will it activate or inhibit? How?
malonyl-CoA by blocking the uptake of fatty acids into the mitochondria
26
How many ATP can be produced by the complete oxidation of one glucose molecule?
Total 36 ATP per glucose molecule
27
What else is produced as well as lost during this process?
Produced=NADH
Lost= CO2
28
This TAG transport lipoprotein you identified above will be transported through the blood stream to sites such as fat cells, muscle cells, and other cells. In fat cells an enzyme is synthesized and secreted to the outside of the cell where it is anchored to the cell. This enzyme catalyze hydrolysis of TAG from circulation so that the fatty acids can be transported into the cell. Which enzyme is this?
* **Lipoprotein lipase**:
* made by the particular cell, and secreted where it anchors itself just outside the cell.
* When chylomicrons, or other circulating triaglycerols arrive at the cell, lipoprotein lipase catalyzes hydrolysis of fatty acids, which are taken up by the cell
29
What is fatty acid activation?
Arrive at the cell and enter the cytosol to form fatty acid CoA \<- yes! To get there converts carboxyl to thioester which is the bond of the fatty acid to Co-ASH
30
Based on what powers ATP production in the electron transport system, what will the fatty acid have more than glucose that makes it a better storage form of potential energy than glucose?
more H+ ions
31
What characterizes the “energy charge” of the cell?
Cellular level of ATP and NADH indicate the energy level
High ATP:ADP and NADH:NAD decreases activity of glycolysis and TCA Cycle
32
Fatty acid biosynthesis:
Define it
Producing new fatty acids
Acetyl-CoA--\>Malonyl-CoA--\>anchored to fatty acid synthase
33
In which complex of the electron transport system does NADH interact?
NADH transfers its electrons and H+ through each complex (I,II,III)
34
How does is start when pyruvate enters
Pyruvate converts to Acetyl-CoA then: Condensation of Acetyl- CoA with oxalosuccinate to form citrate
35
Now that you have looked up the purpose of the TCA cycle and what pyruvate is converted to in this process, you (hopefully) recalled Acetyl-CoA. What does Acetyl-CoA condense with to produce that specific TCA from three questions ago?
a. Acetyl-CoA condenses with Oxalosuccinate to form citrate
36
What is the largest fatty synthesized by fatty acid biosynthesis?
Palmitic acid
37
Each time NADH, FADH2, and oxygen interact with the electron transport system, what gets “pumped” from one part of the mitochondria to another part of the mitochondria?
Hydrogen Ions (H+)
38
How can lactation in over-finished dairy cows result in similar conditions to diabetes?
Lactation hormone cause reduced fat deposition in fat tissue
Increased fatty acid mobilization from fat cells -\> Stimulate lipolysis so much more fatty acid released compared to good body condition cow, hits liver and liver can’t deal with that level of fatty acids = continued oxidation and accumulation causes ketoacidosis
Nutrient and body energy stored support the mammary gland need for milk production (fatty acids)
Over-condition (fat) dairy cows have problems
39
What general reaction do lipases catalyze?
Hydrolysis of carboxyl ester (I’m pretty sure that’s right, but in general they catalyze the hydrolysis of fatty acids)
40
Which enzyme catalyzes the reaction above? (de novo fatty acid synthesis involves carboxylation of acetyl-CoA--\> malonyl-CoA)
**acetyl- CoA carboxylase**
41
How can multiple fetuses in ovine ewes cause a form of pregnancy toxemia?
Ketone production can become excessive if lactation or pregnancy places too many demands on the available glucose -\> fatty acid oxidation synthesis increases in response = ketone production increases
Huge draw of blood glucose from ewe when they reach a certain size
The draw maternal glucose blood glucose just drops dramatically, and insulin secretion is stimulated by blood glucose levels = insulin secretion drops
42
For triacylglycerols (TAG) consumed by all animals, where in the animal will digestion begin?
* Non- ruminants: stomach
* Ruminant: Rumen
43
Hopefully by now you have recognized a pattern regarding getting TAG from a feed source to TAG as a stored source of fatty acids by the animals: Diet TAG -\> intestinal FA’s -\> intestinal cell TAG -\> blood circulation TAG -\> cell surface TAG -\> cell surface FA’s -\> intracellular FA’s -\> stored TAG in fat cell. For the non-ruminant, there are four lipases involved in the above process. What are they (again)?
1. lingual lipases
2. Gastric Lipases
3. Pancreatic lipases
4. colipase Lipase
44
There is an enzyme involved in ATP production associated with the electron transport system. What is the name of this enzyme?
ATP SynthETASE
45
In what part of the cell does the de novo fatty acid synthesis occur?
cytosol
46
What is produced during glycolysis from oxidation that will be used for ATP production in the electron transport system?
NADH
Those hydrogens at mitochondrial membrane FADH
47
With the above enzyme complex, an acetyl-CoA and the product of the reaction in #9 are bonded and a CO2 is released that will be used to recarboxylate another acetyl-CoA in the #9 reaction. What happens to this 4-C structure in the next three reactions. What functional groups are involved? Review the diagram used in the PPT.
1. condense malonyl- ACP with Aceytl ACP (creates 4 C structure Ketone)
2. Reduced to alcohol
3. reduced to alkene
4. reduced to alkane
48
How may ATP can be produced by this oxidation/reduction product? Why is this?
NADH= 3 & FADH= 2
NADH transfers electrons and H+ at top the top of the chain, so there are three locations down the electron transport chain where 2 H+ can be taken up
FADH2 transfers its electrons and H+ at the middle segment so there are only two locations 2 H+ can be taken up
Total ATP from glucose completely oxidized= 36
12 from TCA cycle
49
Which enzyme complex is involved in the subsequent steps in fatty acid synthesis?
**fatty acid synthase**
50
What is pyruvate converted to when it is taken up by the mitochondria?
Acetyl-CoA
51
What is the name of the reaction sequence that will take place that involves breaking down the fatty acid?
**beta- oxidation**
52
In a fed animal how is metabolism characterized in muscle cells
1. Glucose uptake increases.
2. Acetate availability increases.
3. LPL activity is not increased: fatty acids are available for storage.
4. ACC activity increases: increased malonyl-CoA: inhibits B-oxidation.
5. Cellular energy charge is high.
53
Lactation and pregnancy:
1. Glucose decreases from fetal and lactation demands for glucose (for lactose synthesis in the mammary gland).
2. Insulin decreases in response to the decreased glucose.
3. In response to decreased insulin: fatty acids increase, liver ketone production increases, blood pH decreases, the animal becomes ketotic an acidotic.
54
For non-ruminants, where are the 3 lipases that will be involved in the digestion of TAG located and what are they called?
1. 1) lingual lipase: secreted from mouth
2. gastric lipase: secreted from stomach
3. pancreatic lipase: secreted from pancreas
55
How many “complexes” occur in the electron transport system?
Three different complexes
Complex I, Complex II, and Complex III
56
Where does the energy come from to drive ATP synthesis?
Hydrogen flow through ATP synthase
57
In a fed animal how is metabolism characterized in fat cells?
1. Intracellular lipolysis decreases. (cutting fatty acids out of triglycerides)
2. Lipoprotein lipase (LPL) increases: fatty acid uptake increases.
3. Acetyl-CoA carboxylase (ACC) activity increases: fatty acid synthesis increases.
4. Glycerolipid biosynthesis increases.
5. Net effect: Triacylglycerol storage increases.
58
In muscle cells, what does the malonyl-CoA do?
Inhibits fatty acid CoA to go in mitochondria = inhibits fatty acid oxidation
59
What fatty acids are made from this end product?
Oleic, Stearate Acid
60
Fatty acid biosynthesis:
Where in the cell does it occur?
Cytosol
61
In contrasting the de novo fatty acid synthesis with fatty acid oxidation, hopefully by this point in his review you have found some answers. By applying your knowledge of he organic functional groups to this topic you should see the contrast in the two processes:
* De Novo Synthesis: after acetyl- ACP is condensed with the malonyl- ACP a 4 C starting point attained
* 1) **ketone is formed.** -alcohol is dehydrated into alkene -alkene reduced to alkane
* 2) **Fatty acid oxidation** -alkane is oxidized to alkene -alkene hydrated to alcohol -alcohol oxidized to ketone -molecule split releasing acetyl-CoA
62
Which three fatty acids make up most of the TAG stored in fat cells of cattle and market hogs?
1. Palmitate
2. Stearate
3. Oleate
63
How does diabetes affect metabolism in muscle cell
1. Glucose uptake decreases: blood glucose increases.
2. Proteolysis increases: amino acids to liver increases for more
gluconeogenesis: blood glucose increases.
64
What is the largest fatty acid that is synthesized while in part of this enzyme complex?
Palmitate
65
By now you have reviewed the purpose of the TCA cycle and know that it involves oxidation. Since there must be reduction to go along with oxidation, and molecules that occur in the cycle are the things oxidized, what are the two molecules that are reduced during this process?
a. The tenth and final step is pyruvate production, which involves the transfer of the phosphate of phosphoenol pyruvate to ADP to produce ATP and pyruvate. Catalyzed by pyruvate kinase.
66
Where does the TCA cycle occur?
Mitochondria
67
The first reaction in de novo fatty acid synthesis involves carboxylation of acetyl-CoA. What is synthesized? And what is the particular significance of this step with regard to the overall rate of fatty acid synthesis?
* **Malonyl-CoA**
* catalyzed by Acetyl-CoA carboxylase
* important because its the **rate-limiting** step in fatty acid biosynthesis
68
In terms of ATP production per C atom, which produces more, glucose or fatty acid?
fatty acid
69
What is the difference between glycolysis and fatty acid oxidation as to: where in the cell each occurs?
* Glycolysis= cytosol
* Mitochondria
70
In a fasted animal how is metabolism characterized in muscle cell
1. LPL activity increases: increases fatty acid uptake from TG.
2. Fatty acid uptake increases (supplied from the fat cells).
3. ACC decreases: decreases malonyl-CoA activity: removes inhibition of B-oxidation. = increase in Fatty acid oxidation
4. Energy charge is low: TCA cycle rate increases.
71
In the small intestine, the fatty acids will be absorbed and then will be prepared for transport in the blood as WHAT TYPE OF MOLECULE? And then packaged into a lipoprotein CALLED A WHAT?
* Triacylglycerols(TAG)
* Lipoprotein: Chylomicron
72
What enters? What is produced? What is produced that will form ATP later?
Acetyl-CoA enters, condenses with oxalosuccinate to = 4 Carbon --\> 6 Carbon structure (citrate)
2 CO2 are evolved
3 NADH are produced
1 FADH2
1 ATP produced via GTP
GTP is produced to later for ATP from ADP
73
What are the major fatty acids found in triacylglycerols in fat cells of ruminants?
Palmitate, Stearate, Oleic
74
What does pyruvate lose and then change into when it enters the mitochondrial membrane?
Looses the cooh and gains coAsh
75
In a fasted animal how is metabolism characterized in liver cell
1. Glucagon increases causing Gluconeogenesis increases.
2. B-oxidation increases.
3. TCA cycle rate increases.
4. Ketone production increases (from acetyl-CoA overload).
The responses to feeding and fasting are communicated to the cells by hormones, primarily insulin.
76
How much is produced from each glucose oxidized by only the TCA cycle
How much ATP:
Per glucose: 6 NADH, 2 FADH2, 2 GTP
```
Per pyruvate (there are 2 of these per glucose) 3 NADH, 1 FADH2, GTP= 12 ATP per turn of TCA cycle from oxidation/reduction products NADH = 3 ATP each, FADH2 = 2 ATP each
By each turn of the TCA 12 ATP per turn of TCA
```
77
Why are fatty acids a better producer of ATP than glucose?
Will produce more ATP per Carbon
78
what is “TCA” an abbreviation for?
Tricarboxylic acid cycle (or citric acid cycle)
79
By now you know that an ATP is made by the TCA cycle. From which specific compound did the phosphate come from in producing this ATP?
a. GDP
80
In which part of this organelle will the electron transport system be active?
Inner Mitochondrial Membrane
81
What is O2 for? What molecule does it end up incorporated into?
Accepts electrons and binds with H+ to form water
82
Lipases in the body:
Where are they located?
Gastric Lipase= stomach / microbial lipase = rumen
Lingual Lipase= mouth
Pancreatic Lipase= pancreas
Lipoprotein Lipase= tissue that is secreted by the specific cell and located outside that cell
Adipose Triglyeride Lipase= fat cell catalyzes hydrolysis of fatty acid
Hormone- sensitive Lipase= enzyme in fat cell catalyzes hydrolysis of fatty acids
Monoacylglyercol Lipase= third step in hydrolysis
83
In which complex of the electron transport system does FADH2 interact?
FADH transfer its electrons and H+ through the last two complexes. Complex II, II.
Not involved in the first complex
84
After looking up what “TCA” stands for, what is the specific TCA that occurs in the first reaction of the TCA cycle?
Acetyl-CoA condenses with oxalosuccinate to form citrate
85
Why do fat cells perceive the physiological environment to be like fasting during untreated diabetes?
No glucose is being taken up from the blood as insulin is not stimulating this on the cell
Insulin decreases a diabetic is missing insulin
Level of insulin decreases a lot with fasting
86
What is produced in the first step of fatty acid biosynthesis?
Change acetyl- CoA and malonyl CoA by replacing the –CoA with acyl- carrier protein (ACP)
87
For ruminants, the microbes reduce lipases so fatty acids and not nearly as much TAG will arrive at the small intestine. These fatty acids will be absorbed by the small intestine and reformed into TAG and the rest is the same as the non-ruminant. The amount of fat on a market steer cannot be accounted for by just the amount of TAG it would have consumed during its lifetime. The same would be expected from a market hog. So, where did the fat come from?
* once immediate dietary needs for animals met the extra is stored for later
88
What is produced when TCA first starts?
Citrate- tricarboxylic acid-TCA
89
How does diabetes affect metabolism in fat cells
Fat cells:
1. Increased response to catecholamines.
2. Increased fatty acid release.
3. Decreased LPL activity.
4. Blood TG increased.
90
Lactation
1. Fatty acid release from fat cells increases.
2. If excessive the cow can become ketotic.
91
What is produced in the TCA cycle?
Glycolysis produces 2 ATP, 2 NADH, 2 pyruvate (per glucose molecule)
Fatty acid oxidation produces acetyl CoA, 1 FADH2, and 1 NADH (know the dividing and subtracting thing to find the number depending on the number of carbons)
92
Why do blood glucose and blood ketones get so high in untreated diabetes?
Gluconeogenesis keeps occurring in the liver due to glycogen release and the availability of substrates from muscle proteolysis
Low insulin allows for increased mobilization of fatty acids from adipocytes
Unregulated fatty acid oxidation
93
Once inside the fat cell, the fatty acids are esterification again so the can be stored as WHAT TYPE OF MOLECULE?
Glycerol- 3 Phosphate (TAG)
94
These things that are getting pumped are associated with ATP production. What do these things do that contributes to ATP production?
Flow of ions causes the generation of electrical energy which is used to drive the phosphorylation of ADP to ATP.
ATP synthase provides the channel for flow of H+, and the enzyme needed to catalyze phosphorylation.
95
By the time the TCA cycle has metabolized one Acetyl-CoA, what three specific molecules and how many of each will have been produced that will contribute to the pool of ATP needed by the cell?
a. 3 NADH
b. 2 CO2
c. 1 FADH2
96
During the cycle, as what molecule will the carbon atoms that originated in Acetyl-CoA end up?
CO2
97
Where does fatty acid activation in the cell does it occur?
Cytosol (activation), but fatty acid oxidation occurs in the mitochondria
98
What purpose does Malonyl-CoA serve in the muscle cell
Malonyl-CoA inhinits transoprt of fatty acids from the cytosol into the mitochondria in the fed animal
99
How many cycles through fatty acid synthase reactions will be needed to produce a fatty acid containing 16 C
8
100
After acetate enters the fat cell of a ruminant, in what part of the cell is it converted to acetyl-CoA
cytosol
101
When fatty acids are to be mobilized from fat cells which enzyme catalyzes hydrolysis of the second fatty acid from TAG
hormone-sensitve lipase
102
Based on the number of hydrogen ions that are pumped in after interaction of FADH2 with the electron transport system, how many ATP can be synthesized
2
103
For each complete turn of the fatty acid oxidation cycle, what combination of materials with be formed
1 NADH, 1 FADH2, 1 acetyl-CoA
104
What is the purpose of O2 in metabolsim
terminal electron acceptor in the electron transport system
105
What molecule does the O2 become a part of at the end of the electron transport system
water
106
Which one of the following most accuratly depicts the difference between glycolysis and fatty acid oxidation
fatty acid oxidation occurs in the mitochondria and produces only acetyl-CoA, NADH, and FADH2 whereas glycolysis occurs in the cytosol and produces a small amount of ATP and NADH
107
How many ATP will be formed from the complete oxidation of one glucose molecule
36
108
Where does fatty acid biosynthesis occur in a ruminant, pig, and chicken
Ruminant-pig= fat cells
Chicken= liver
