Quiz 1 Flashcards
(98 cards)
1
Q
where in the body does gluconeogenesis occur?
A
liver, kidneys, small intestine
2
Q
which tissues exhibit high PPP activity?
A
lactating mammary glands
phagocytic cells
lung and liver tissue
3
Q
Normal alpha linoleic acid (ALA) intake percentage in adults?
0.6-1.2% 5-10% 10-35% 20-35% 45-65%
A
0.6-1.2%
4
Q
describe how insulin and glucagon influence glycolysis
A
glucagon inhibits
insulin increases
5
Q
what is the rate limiting step of glycolysis and what are its players?
A
fructose-6-phosphate (phosphofructokinase) fructose-1,6-bisphosphate)
6
Q
what are the essential fatty acids?
A
linolenic acid
alpha linolenic acid
conditionally DHA and EPA
7
Q
describe how glucose influences glycolysis
A
excess inhibits
8
Q
which three steps in glycolysis are irreversible and what are the players in each?
A
glucose (hexokinase/glucokinase) glucose-6-phosphate
fructose-6-phosphate (phosphofructokinase) fructose-1,6-bisphosphate
phosphoenolpyruvate (pyruvate kinase) pyruvate
9
Q
disease characterized by loss of pancreatic beta cell function. what is the result of this dysfunction
diabetes hemolytic anemia fanconi-bickel syndrome Von Gierke disease (GSD1a) galactosemia Tarui
A
diabetes;
insulin deficiency, resistance
10
Q
where is glycogen stored?
A
liver and muscle
11
Q
Normal fat intake percentage in adults?
0.6-1.2% 5-10% 10-35% 20-35% 45-65%
A
20-35%
12
Q
which is the rate limiting step of gluconeogenesis and what are the players of this reaction?
A
F-1,6-BP (F16BPhosphatase) F-6-P
13
Q
Which fatty acids can be found in the outer leaflet of the cell membrane?
A
Sphingomyelin
Glycolipids
Phosphatidylcholine
14
Q
What fatty acids can be found in the inner leaflet of the cell membrane?
A
Phosphotidylinositol
Phosphotidylserine
Phosphotidylethanolamine
15
Q
Ca2+ concentration is greater inside the cell or outside the cell?
A
Outside
10000 fold!!
16
Q
K+ concentration is greater inside the cell or outside?
A
Inside
17
Q
Na+ concentration is greater inside or outside the cell?
A
Outside
18
Q
Cl- concentration is greater inside or outside the cell?
A
Outside
19
Q
What is the difference between P-type ATPases and ABC transporters?
A
With P type ATPases, the protein is phosphorylated
The protein is not phosphorylated in ABC transporters
20
Q
After ATP hydrolysis, where does phosphorylation occur on P-type ATPases?
A
On an aspartate residue
21
Q
After ATP hydrolysis, where does phosphorylation occur on ABC transporters?
A
ABC transporters are not phosphorylated
22
Q
The sodium potassium pump is an example of which type of transporter?
A
P-type ATPase
23
Q
Antibiotic resistance is a result of upregulation of which type of transporter?
A
ABC transporters
24
Q
The sodium-glucose transporter is an example of which type of transport?
A
Secondary active
Symporter
Gradient maintained by the sodium potassium pump
25
The sodium calcium exchanger is what type of transporter?
Secondary active
Anti porter
Gradient maintained by the sodium potassium pump
26
Describe the function of the sodium-calcium exchanger (NCX)
3Na+ down concentration gradient
| 1 Ca+ against concentration gradient
27
Describe how D-glucose and D-galactose are transported from the intestinal lumen into the bloodstream
Secondary active transport into the enterocyte via SGLT1 transporter
Facilitated diffusion into blood stream via GLUT2
28
Describe how fructose is transported from the intestinal lumen into the bloodstream
Facilitated diffusion into enterocyte via GLUT5 on apical side
Facilitated diffusion into bloodstream via GLUT2 on basal side
29
What maintains sodium concentration gradient and resides on the basal side of the enterocyte membrane in the small intestine?
Na+/K+ pump
30
A salad has 8g of protein, 10g of carbs and 20g of fat with the dressing. To drink, you have a beer that contains 30g of carbs and 5g of alcohol. How many calories is this meal?
```
Protein = 4 cals/g
Carbs = 4cals/g
Fats = 10cals/g
Alcohol = 7cals/g
```
427cals
31
how would you determine how much protein an individual needed?
nitrogen from urine sample
| 1g nitrogen = 6.25 g protein
32
where is GLUT7 located and what is its significance?
in the ER
| part of G6Phosphatase (G6P--->glucose)
33
this type of glycogen provides a fuel reservoir for physical activity
muscle glycogen
34
glycogen is reduced and extended from which end?
reducing end
non reducing end
non reducing
35
where in glycolysis is ATP produced for the first time and what are the players in this reaction?
1,3-bisphosphoglycerate (phosphoglycerate kinase) 3-phosphoglycerate
36
where in the body does glycolysis occur?
exercising muscle, RBCs, brain
37
describe how ATP and AMP influence glycolysis
ATP inhibits
| AMP increases
38
what is the net yield of glycolysis?
2 ATP
2 Pyruvate
2 NADH
39
hypoglycemia and a buildup of lactate are hallmark traits of which disorder affecting the rate limiting gluconeogenesis? similar Tarui disease
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
F-1,6-BPhosphatase deficiency
40
which disease would most directly impact the rate limiting step of glycolysis? why?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
Tarui disease; PFK-1 deficiency
41
what effect does glucagon have on PFK-2/FBPase-2? why?
phosphorylates via protein kinase A; because the enzyme assumes phosphatase function, dephosphorlating F2,6BP to fom F6P which can be used for gluconeogenesis
42
what is the rate limiting step of the pentose phosphate pathway and what are the players in this reaction?
G6P (G6PD) lactone
43
function of glycogen in muscle?
fuel reservoir for physical activity
44
fasting hypoglycemia, lactic acidosis, and glycogen buildup from the inability to convert G6P to glucose is characteristic of which disease?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
Von Gierke disease (GSD1a)
45
Normal carbohydrate intake percentage in adults?
```
0.6-1.2%
5-10%
10-35%
20-35%
45-65%
```
45-65%
46
disease characterized by elevated lactate dehydrogenase and unconjugated bilirubin. what does this elevation say?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
hemolytic anemia;
| those are normally intracellular components that must mean cell lysis
47
disease caused by mutation in GLUT2 transporter? where is this transporter located and what affinity does it have for glucose?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
fanconi-bickel
48
what effect does glucagon have on PK? why?
phosphorylates PK via protein kinase A; phosphoenol pyruvate can enter gluconeogenesis
49
fructose is taken up in the liver via which GLUT transporter?
```
1
2
3
4
5
6
7
```
5
50
when is glycolysis favored?
when blood glucose/insulin is high
51
_______ fats are most linked to increased risk of cardiovascular disease
saturated
unsaturated
trans
cis
trans
52
how does gluconeogenesis "bypass" the key regulatory steps of glycolysis? which enzymes are bypassed by which?
pyruvate carboxylase and PEP carboxykinase (pyruvate kinase)
F-1,6-BPhosphatase (PFK)
G-6-Phosphatase (hexokinase/glucookinase)
53
describe the function and significance of the Cori cycle
lactate from anaerobic glycolysis in RBC and exercising muscle is used in the liver to regenerate glucose that is transported back to those muscles for energy
prevents lactate accumulation
54
which end of glycogen possesses glycogenin?
reducing end
non reducing end
reducing end
55
what effect does insulin have on PFK-2/FBPase-2? why?
dephosphorylates via protein phosphatases; because the enzyme assumes kinase activity, phosphorylating F6P to F2,6BP which activates PFK-1 and drives the rate limiting step of glycolysis
56
this type of glycogen regulates blood glucose levels
liver glycogen
57
Overweight range for BMI?
25-29.9
58
Normal range for BMI?
18.5-24.9
59
what are the functional roles that fiber has on glycemic index? and how much is recommended daily?
helps to reduce glycemic load
aides in gut absorption and motility
20-35g/day
~14g/1000kcal
60
diabetes would most heavily impact the function of which GLUT transporter and why? this transporter is present in which types of tissues?
```
1
2
3
4
5
6
7
```
4
these transporters are insulin dependent
skeletal muscle, adipose, heart
61
which are negative regulators of glycolysis?
```
F-6-P
F-1,6-P
F-2,6-P
Glucose
G-6-P
citrate
AMP
insulin
glucagon
cortisol
ATP
```
```
F-6-P
citrate
G-6-P
glucagon
cortisol
ATP
```
62
t/f
insulin signaling causes the fusion of vesicles with the plasma membrane and placement/insertion of the GLUT1 transporter?
f
| only GLUT4 transporters are insulin dependent
63
what is the "trapping" step of glycolysis and what are its players?
glucose (hexokinase/glucokinase) glucose-1-phosphate
64
which are positive regulators of glycolysis?
```
F-6-P
F-1,6-P
F-2,6-P
Glucose
G-6-P
citrate
AMP
insulin
glucagon
cortisol
ATP
```
```
F-1,6-P
F-2,6-P
Glucose
insulin
AMP
```
65
what effect does insulin have on PK? why?
dephosphorylates P via protein phosphatases; to stimulate glycolysis (phosphoenol pyruvate---->pyruvate)
66
which step of gluconeogenesis is the only one that occurs in the mitochondria and what are the players of this reaction?
pyruvate (pyruvate carboxylase) OAA
67
this disease is characterized by a deficiency in PFK-1, exercise induced muscle weakness, and hemolytic anemia
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
Tarui disease
68
which is the reversible phase of the pentose phosphate pathway?
oxidative
non oxidative
non oxidative
69
Normal linoleic acid intake percentage in adults?
```
0.6-1.2%
5-10%
10-35%
20-35%
45-65%
```
5-10
70
function of glycogen in liver?
blood glucose regulation
71
where in glycolysis is NADH produced and what are the players in this reaction?
glyceraldehyde-3-phosphate (GAPDH) 1,3-bisphosphoglycerate
72
Normal protein intake percentage in adults?
```
0.6-1.2%
5-10%
10-35%
20-35%
45-65%
```
10-35%
73
where in glycolysis is ATP produced for the second and final time and what are the players in this reaction?
phosphoenolpyruvate (pyruvate kinase) pyruvate
74
PFK-2/FBPase-2 is a bifunctional enzyme that acts as a kinase in its _______ form and as a phosphatase in its ______ form
dephosphorylated
| phosphorylated
75
describe the differences between hexokinase and glucokinase in terms of location, affinity, and regulation
hexokinase is present in all cells, has high affinity for glucose, and is inhibited by G6P
glucokinase is only present in the liver and pancreas, has low affinity for glucose and is regulated by insulin and glucagon
76
where does gluconeogenesis take place within the cell?
starts in the mitochondria, completes in the cytosol
77
describe where each of the GLUT transporters are found (1-4)
1) ubiquitous
2) liver/pancreas
3) neurons
4) skeletal muscle, adipose, heart
78
which GLUT transporter has the lowest affinity for glucose?
GLUT2
79
where in carbohydrate metabolism is biotin used as a cofactor and what are this reactions players?
pyruvate (pyruvate carboxylase) oxaloacetate
80
which is usually caused by some sort of deficiency in PK?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
hemolytic anemia
81
patient presents with failure to thrive, and accumulation of galactitol, which disease would be representative of this presentation?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
galactosemia
82
deficiency in glucose 1P uridyltransferase (GALT) leads to this disease. what is a consequence of this disease?
```
diabetes
hemolytic anemia
fanconi-bickel syndrome
Von Gierke disease (GSD1a)
galactosemia
Tarui
```
galactosemia
| accumulation of galactitol
83
what is the precursor for fatty acid synthesis?
where in the cell is it formed?
where in the cell is it actually used for FA synthesis and how does it get there?
acetyl CoA
mitochondria
cytosol
links up with OAA to form citrate, shuttled across the mito membranes to the cytosol, converted back to acetyl CoA and OAA
84
what is the rate limiting step of FA synthesis and what are the players in this reaction?
acetyl CoA (acetyl CoA carboxylase) malonyl CoA
85
where in FA synthesis is biotin used as a cofactor and what are the players in this reaction?
acetyl CoA (acetyl CoA carboxylase) malonyl CoA
86
what is the substrate for FA synthase? what other role does it serve?
malonyl CoA
| inhibits carnitine acyltransferase (rate limiting step in FA degradation)
87
describe the order of reactions catalyzed by FA synthase
condensation
reduction
dehydration
reduction
CRDR
88
describe describe the allosteric regulators of FA synthesis (acetyl CoA carboxylase)
citrate promotes
| palmitate/long chain FAs inhibit
89
describe the effects of each of these regulators of FA synthesis (acetyl CoA carboxylase)
insulin
glucagon
epinephrine
AMP
insulin: dephosphorylates via protein phosphatases; activates
glucagon/epinephrine: phosphorylates via PKA; inactivates
AMP: inactivates via AMP kinase
90
which molecule serves as a carbon donor in FA elongation in the SER?
malonyl CoA
91
which molecule serves as a carbon donor in FA elongation in the mitochondria?
acetyl CoA
92
describe TAG synthesis in intestinal cells.
| What molecules are produced and where are they released?
TAGs from diet broken down to MAGs and FFAs > DAGs > TAGs > chylomicrons release into lymphatics and enter blood via thoracic duct
93
describe TAG synthesis in hepatocytes.
| what molecules are produced and where are they released?
glucose/glycerol > G3P + fatty acyl CoA (x2) > DAGs > TAGs > VLDLs released into the blood
94
TAG synthesis in the intestines is promoted by _______
dietary TAGs
95
TAG synthesis in hepatocytes is promoted by _______
excess carbohydrates
96
describe TAG synthesis in adipocytes.
| what molecules are produced and where are they released?
dietary glucose > G3P + fatty acyl CoAs (from chylomicrons and VLDLs) > DAGs > TAGs stored in adipocytes themselves
97
what is the rate limiting step of FA degradation and what are the players in this reaction?
fatty acyl CoA (carnitine palmitoyltransferase I) fatty acyl carnitine
98
describe the order of reactions in beta oxidation
oxidation
hydration
oxidation
thiolysis
