Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physiology II Test II - Jourdan > Energy Balance and Metabolism I > Flashcards

Energy Balance and Metabolism I Flashcards

1
Q

To produce energy, what is metabolized?

A

Proteins, carbohydrates and fats are oxidized to form ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ΔG° = std free energy difference which is the difference in what?

A

Difference in free energy when 1 mole of each reactant is converted to 1 mole of each product at 1 atm pressure at 25°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

-ΔG° =

A

Exergonic reation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

+ΔG° =

A

Endergonic reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ATP -> ADP + Pi

ΔG° = ?

A
  • 7300 cal/mole

- 12000 cal/mole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What becomes the final common pathway for the transport of almost all the carbohydrates to the tissue cells?

A

Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What sugars are all interconvertible?

A

Galactose, glucose, and fuctose (all hexoses)

Each can be phosphorylated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What sugars can be converted to fuctose-6-phosphate and enter the glycolytic pathway?

A

Galactose and glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transport of glucose into tissue cells is via what?

A

Active sodium-glucose co-transport
-Active transport of sodium provides energy for absorbing glucose against concentration gradient

Via facilitated transport
-only transported from higher to lower concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What increased glucose transport x10?

A

insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What prevents diffusion of glucose out of the cell?

A

Phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where can phosphorylation of glucose be reversed?

A

In liver, renal, and intestinal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the roles of the following enzymes?
Glucokinase
Phosphatase
Phosphorylase

A

Blood glucose to glucose 6 phosphate
Glucose 6 phosphate to blood glucose
Glycogen to Glucose 1 phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are factors that can activate phosphorylase?

A

Epinephrine (from adrenal medulla)

Glucagon (from alpha cells of pancreas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the effects of phosphorylase?

A

Promotes conversion of glycogen to glucose

Glucose can then be released into blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the end products of glycolysis?

A

Pyruvic acid (2)
Hydrogens (4): release is catalyzed by dehydrogenase
ATP (2): 2 where needed at the beginning so 4 is total and net is 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the end products of pyruvic acid -> Acetyl-CoA?

A

Acetyl-CoA (2)
Hydrogens (4): release is catalyzed by dehydrogenase
Carbon dioxide (2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where does the citric acid cycle occur?

A

Mitochondrial matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the end products of citric acid cycle?

A

Hydrogens (16): release by dehydrogenase
ATP(2)
Carbond dioxide (4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the net reaction (excluding glycolysis) of the citric acid cycle?

A

2 Acetyl-CoA + 6 H2O + 2 ADP -> 4 CO2 + 16 H + 2 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where does oxidative phosphorylation take place?

A

Mitochondrial cristae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the fate of hydrogen atoms from cycles previous to oxidative phosphorylation?

A
  1. Hydrogens are removed in pairs
  2. One member of each pair becomes a hydrogen ion
  3. The other combines with NAD+->NADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the fate of electrons removed from hydrogen ions?

A

They enter the electron transport chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the major components of the electron transport chain?

A

Flavoprotein
Several iron sulfide proteins
Ubiquinone (Q)
Cytochrome A3 (cytochrome oxidase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Where is Cytochrome A3 located? What role does it play?
Located on inner membrane | Can give up two electrons to oxygen
26
Describe the cheiosmotic mechanism part I
Electrons pass through chain: release large energy Energy used to pump hydrogen ions from inner matrix into outer chamber between inner and outer membranes High concentration of H+ in chamber Strong negative potential created in inner matrix
27
Describe the cheiosmotic mechanism part II
H+ ions flow from high to low through ATP synthetase Energy derived from H+ flow converts ADP to ATP For each 2 electrons that pass through electron transport chain, up to 3 ATP molecules are synthesized **note that the 2 pairs of hydrogens derived from citric acid cycle enter the ECC at a later point and provide energy for 2 ATP molecules per pair
28
In summary of oxidative phosphorylation,the number of ATPs formed per glucose molecule = ?
2 ATPs from glycolysis 2 ATPs from citric acid cycle 34 ATPs from oxidative phosphorylation
29
What is the maximum number of ATPs per glucose molecule ?
38
30
How many calories produced per mole of glucose?
38 x 12,000 cal/mole = 456,000
31
efficiency of calories/mole of glucose =
456,000/686,000 = 66% efficiency
32
What is the pentose phosphate pathway?
A cyclical pathway in which one molecule of glucose is metabolized for each revolution of the cycle
33
For every six molecules of glucose that enter the PPP, how many molecules of glucose are resynthesized?
five
34
What is the PPP mostly used for?
The synthesis of fats and other substances
35
Hydrogens generated from the PPP are bound to what?
NADP+ instead of NAD+
36
What is NADP+ used for?
Used in the synthesis of fats from carbohydrates
37
In the liver what is broken down by the PPP?
glucose is broken down producing excess NADPH
38
What does NAPDH participate in?
The conversion of Acetyl-CoA into fatty acid chains
39
Glucose is preferentially stored as what?
Glycogen until the storage cells (liver and muscle) are saturated
40
What happens to excess glucose?
Converted into fat (liver and fat cells) and stored in fat cells
41
Most triglycerides are digested into what?
Monoglycerides and fatty acids
42
Intestinal epithelial cells resynthesize monoglycerides and fatty acids into what?
Triglycerides that enter the lymph as chylomicrons
43
What is absorbed to the chylocmicron surfaces?
Apoprotein B
44
Chylomicrons are transported to the venous system via what?
the thoracic duct
45
Chylomicrons are removed from the blood by various tissues, especially:
Adipose tissue Skeletal muscle Heart
46
Adipose tissue, skeletal muscle and heart synthesize lipoprotein lipase which:
Is transported to surface of capillary epithelial cells | Hydrolyzes chylomicron triglycerides, releasing fatty acids and glycerol
47
Fatty acids can be used as what?
Fuel or again synthesized into triglycerides
48
How much of the plasma fatty acid is replaced every 2-3 minutes?
50%
49
All normal energy requirements of the body can be provided by what?
The oxidation of fatty acids without using carbohydrates or proteins as an energy source
50
What conditions increase the utilization of fat for energy?
Starvation | Diabetes mellitus
51
Lipoproteins synthesized by intestinal cells are:
Chylomicrons
52
Liporoteins synthesized by the liver are:
Very low density L VLDLs Intermediate density L IDLs Low density L LDLs High density L HDLs
53
Lipoproteins transport what in the blood?
Lipids
54
Describe VLDLs
High concentrations of triglycerides and moderate amounts of cholesterol and phospholipids Transport lipids mainly from liver to adipose tissue
55
Describe LDLs
High concentration of cholesterol and moderate concentration of phospholipids
56
Describe HDLs
High concentration of proteins and low concentration of cholesterol and fatty acids
57
What are the principal functions of the liver in lipid metabolism?
?
58
Under what conditions do large quantities of triglycerides appear in the liver?
?
59
Trigylcerides are hydrolyzed into what?
Fatty acids and glycerol which are transported in blood to tissues
60
Almost all cells use fatty acids for energy except:
Brain cells and red blood cells
61
What is glycerol converted to?
Glycerol-3-phosphate
62
Fatty acids are converted to what in the mitochondria? | What process is used?
Acetyl-CoA | Beta oxidation
63
What is used as a carrier molecule into the mitochondria?
Carnitine
64
Acetyl-CoA enters the citric acid cycle by binding to what?
Oxaloacetic acid
65
Hydrogens enter the ________ oxidative system
Chemiosmotic
66
Products from beta-oxidation of one molecule of stearic acid:
9 aceytl-CoA molecules | 146 molecules of ATP
67
Degradation of fatty acids in the liver releases what?
Many acetyl-CoA not sued for metabolism
68
2 acetyl-CoAs condense to form what?
Acetoactic acid
69
Some of the acetoacetic acid is converted to:
B-hydroxybutryic acid | acetone
70
Acetoacetic acid, β-hydroxybutryic acid, and acetone are all examples of what? They all diffuse back into cells and are converted to what?
ketone bodies Acetyl CoA
71
If concentration of ketone bodies increase above normal blood what occurs?
Ketosis occurs
72
What are conditions favoring ketosis?
Starvation Diabetes Diet composed almost entirely of fat
73
Synthesis of fatty acids is a 2 step process that involves what?
Malonyl-CoA and NADPH
74
What is the importance of fat synthesis?
M0re fat can be stored in tissues than carbohydrates | Weight-for-weight, fat contains about 2.5x the energy of carbohydrates
75
Why are fats poorly synthesized during insulin insufficiency?
?
76
Why are carbohydrates preferred over fats for energy?
?
77
Describe the development of atherosclerotic plaque
Damage to vascular endothelium Circulating monocytes and LDLs accumulate at injury site Monocytes become macrophages Fatty streaks form Surrounding fibrous and smooth muscle tissues form large plaques
78
What does damage to vascular endothelium cause?
Increases the expression of adhesion molecules | Decreases release of NO and other substances that prevent adhesion of macromolecules and cells
79
How do monocytes enter the injury site in the process of atherosclerotic plaque development?
Cross endothelium Enter intima And become macrophages
80
What do macrophages do in the process of atherosclerotic plaque development?
Ingest lipoproteins become foam cells Form visible fatty streaks
81
What happens to the fatty streaks in the process of atherosclerotic plaque development
Grow larger and coalesce
82
Surrounding fibrous and smooth muscle tissues in the process of atherosclerotic plaque development go on to form what?
They proliferate and form large plaques
83
Large plaques may occlude what?
lumen
84
Large plaques may become what?
Sclerotic or fibrotic and may become calcified
85
What are the basic causes of atherosclerosis?
``` Increased LDLs Familial hypercholesterolemia (Defective LDL receptors) ```
86
What lipoprotein may be able to absorb cholesterol crystals that are beginning to be deposited in arterial walls?
HDLs

Physiology II Test II - Jourdan (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions