Carbohydrates Flashcards
1
Q
Sum of all the chemical reactions in a cell, tissue, or the whole body
A
Metabolism
2
Q
Synthesis of compounds from smaller raw materials
A
Anabolic
3
Q
Breakdown of larger molecules
A
Catabolic
4
Q
Catabolic pathway produces reducing equivalents and ATP mainly via
A
Respiratory chain
5
Q
Crossroads of metabolism
Between anabolic and catabolic pathways
A
Amphibolic
6
Q
Second messenger of Glucagon
A
cAMP
7
Q
Second messenger of ANP and Nitric Oxide
A
cGMP
8
Q
Second messenger of Insulin, Insulin-like growth factor
A
Tyrosine Kinase
9
Q
Second messenger of Glucocorticoids, Thyroid hormones
A
Intracellular
10
Q
Protein Kinase of cAMP
A
Protein Kinase A
11
Q
Second messenger of IP3/DAG
A
Protein Kinase C
12
Q
Second messenger of cGMP
A
Protein Kinase G
13
Q
Most abundant organic molecules in nature
Major energy source
Storage form of energy
A
Carbohydrates
14
Q
The sugar units are linked together by
A
Glycosidic bond
15
Q
Examples of Monosaccharides (Hexoses
A
Glucose
Fructose
Galactose
Mannose
16
Q
Main metabolic fuel for tissues
A
Glucose
17
Q
Oxidation of glucose yields
A
Glucuronic acid
18
Q
Reduction of glucose yields
A
Sorbitol
19
Q
Carbohydrate obtained from fruit juices
A
Fructose
20
Q
Carbohydrates obtained from lactose in dairy products
A
Galactose
21
Q
Constituents of glycoproteins
A
Mannose
22
Q
Examples of Monosaccharides (Pentoses)
A
Ribose
Ribulose
Xylulose
23
Q
Structural component of nucleic acids and coenzymes
A
Ribose
24
Q
Intermediate in pentose phosphate pathway
A
Ribulose
25
Excreted in the urine in essential pentosuria
Xylulose
26
Examples of Disaccharides
Sucrose
Lactose
Maltose
27
Glucose + Fructose
Sucrose
28
Glucose + Galactose
Lactose
29
Glucose + Glucose
Maltose
30
May be excreted in the urine in pregnancy
Lactose
31
Intermediate in the digestion of starch
Maltose
32
Examples of Polysaccharides
Glycogen
Starch
Cellulose
Inulin
33
Storage polysaccharide in animals
Glycogen
34
Most important dietary carbohydrate in cereals, potatoes, legumes, and other vegetables
Starch
35
Chief constituent of plant cell walls
Cellulose
36
Used to determine glomerular filtration rate
Inulin
37
Identify the GLUT: Requires insulin
GLUT 4
38
Identify the GLUT: Brain and RBC
GLUT 1
39
Identify the GLUT: Liver and Pancreas
GLUT 2
40
Identify the GLUT: Absorption of fructose in small intestine by facilitated diffusion
GLUT 5
41
Identify the GLUT: Adipose tissue, skeletal and cardiac muscle
GLUT 4
42
Identify the GLUT: Brain, Kidney, Placenta
GLUT 3
43
Major pathway for glucose metabolism that converts glucose into 3 carbon compounds to provide energy
Glycolysis
44
Where does glycolysis occur
Cytosol
45
Substrate of glycolysis
Glucose
46
End products of glycolysis
2 molecules of either pyruvate or lactate
47
Rate limiting step of glycolysis
Phosphofructokinase-1
48
Step 1 of glycolysis
Glucose to Glucose 6 phosphate
49
Step 3 of Glycolysis
Phosphorylation of Fructose 6 phosphate
50
Step 10 of Glycolysis: Formation of Pyruvate
Phosphoenolypyruvate to Pyruvate by enzyme Pyruvate Kinase
51
Due to mutations that decrease the activity of glucokinase
Maturity onset diabetes of the young yype 2
52
Asymptomatic
Hyperglycemia is commonly discovered during routine screening
Majority of the these patients do not require treatment, except during pregnancy
Maturity onset diabetes of the young type 2
53
Pentavalent arsenic competes with inorganic phosphate as a substrate for glyceraldehyde-3-P dehydrogenase
Arsenic Poisoning
54
Leads to thiamine deficiency due to poor diet and because alcohol inhibits thiamine absorption
Chronic Alcoholism
55
Chronic Alcoholism may cause potentially
Fatal pyruvic and lactic acidosis
56
End product of Anaerobic Glycolysis
Lactate
57
End product of Aerobic Glycolysis
Pyruvate
58
Type of Glycolysis: NADH is used to reduce pyruvate to lactate
Anaerobic Glycolysis
59
Identify the enzyme: Pyruvate ---> Lactate
Lactate dehydrogenase
60
______ is seen in vigorous exercise, septic shock, and cancer cachexia
Lactic acidosis
61
Type of Glycolysis: NADH cannot pass through the inner mitochondrial membrane, and thus requires shuttles for transport
Aerobic Glycolysis
62
Identify the enzyme: 1,3 BPG ---> 2,3 BPG
Biphosphoglycerate mutase
63
Identify the enzyme: Pyruvate ---> Acetyl CoA
Pyruvate dehydrogenase complex
64
Identify the enzyme deficiency in Glycolysis with clinical presentation of Hemolytic Anemia
Aldolase A, Pyruvate Kinase
65
Most common enzyme defect in glycolysis
Pyruvate Kinase
66
Identify the enzyme deficiency in glycolysis with clinical presentation of low exercise capacity, esp. on high carbohydrates diets
Muscle phosphofructokinase
67
Provide lipids as alternative fuel
Muscle phosphofructokinase
68
Most common cause of congenital lactic acidosis; Treat with ketogenic diet
Pyruvate dehydrogenase
69
Final common pathway for the aerobic oxidation of carbohydrates, lipids, and proteins
Citric Acid Cycle
70
Major pathway for formation of ATP
Citric Acid Cycle/Krebs Cycle/TCA
71
Where does Citric Acid Cycle occur?
All cells with mitochondria (Mitochondrial matrix)
72
Substrate of Citric Acid Cycle
Acetyl CoA
73
What are the products of Citric Acid Cycle?
2 CO2
1 GTP
3 NADH
1 FADH2
74
Citric Acid Cycle: Which step is rate-limiting?
Isocitrate-->a-ketoglutarate
| Enzyme: Isocitrate dehydrogenase
75
It is the process of synthesizing glucose from non-carbohydrate precursors, in order to prevent hypoglycemia during a fast
Gluconeogensis
76
End product of Gluconeogenesis
Glucose
77
Rate-limiting step of gluconeogenesis
Fructose 1,6 -biphosphatase
78
Important steps of Gluconeogenesis
Steps 1&2: Pyruvate-->OAA-->PEP
Oxaloacetate-->Phosphoenolpyruvate
Step 9: Fructose 1,6 BP --> Fructose 6-P
Step 11: Glucose-6-Phosphate --> Glucose
79
Synthesis of glycogen
Glycogenesis
80
Branched polymer of a-D-glucose
Glycogen
81
Where does glycogenesis occur?
Liver and muscle
82
What is the substrate of Glycogenesis
a-D-glucose
83
What is the product of Glycogenesis
Glycogen
84
Rate limiting step of glycogenesis
Glycogen synthase
85
Protein that serves as a primer for glycogen synthesis when glycogen is completely depleted
Glycogenin
86
Elongation of glycogen chains
Glycogen synthase
87
Shortening of glycogen chains
Glycogen phosphorylase
88
Well feed
Dephosphorylated
89
Fasting
Phosphorylated
90
Mobilizing stored glycogen
Glycogenolysis
91
Substrate of Glycogenolysis
Glycogen
92
Products of Glycogenolysis
Glucose in liver
| Glucose-6-phosphate in muscle
93
Rate limiting step of Glycogenolysis
Glycogen phosphorylase
94
Glucose 6 phosphatase deficiency
Von Gierke disease
95
Increased glycogen in liver
| Severe hypoglycemia
Von Gierk Disease
96
Lysosomal acid maltase deficiency
Pompe disease
97
Increased glycogen in lysosomes
Pompe disease
98
Clinical features of Pompe disease
Juvenile onset: Heart Failure
| Adult onset: Muscle dystrophy
99
Debranching enzyme deficiency
Cori disease
100
Branching enzyme deficiency
Andersen disease
101
Muscl phosphorylase deficiency
McArdle syndrome
102
Liver phosphorylase deficiency
Hers disease
103
Identify the enzyme: Galactose -> Galactose 1-P
Galactokinase
104
Identify the enzyme: Galactose 1P + UDP glucose -> UDP galactose + Glucose 1P
Galactose 1-P uridyl transferase (GALT)
105
Identify the enzym: UDP-galactose -> UDP-glucose
UDP-hexose 4 epimerase
106
Cataracts in early childhood
Galactokinase deficiency
107
Treatment of Galactokinase deficiency
Eliminate sources of galactose from the diet
108
More severe symptoms
| Poor growth in children, severe mental retardation, and liver damage
Classic galactosemia
109
Treatment for Classic galactosemia
Eliminate sources of galactose from the diet
| Newborn screening available
110
Identify the enzyme: Fructose -> Fructose 1-P
Fructokinase/Hexokinase
111
Identify the enzyme: 1-P -> DHAP + Glyceraldehyde
Aldolase B
112
Enzyme deficiency: Classic Galactosemia
Galactose 1 phosphate uridyl transferase deficiency
113
Enzyme deficiency: Essential fructosuria
Fructokinase deficiency
114
Profound hypoglycemia and vomiting after consumption of fructose or sucrose
Symptoms appear after weaning from milk
Hereditary fructose intolerance
115
Enzyme deficiency: Hereditary fructose intolerance
Aldolase B deficiency
116
Treatment for Hereditary fructose intolerance
Eliminate source of fructose, sucrose, and sorbitol from the diet
117
Identify the enzyme: Glucose -> Sorbitol
Aldolase reductase
118
Identify the enzyme: Sorbitol -> Fructose
Sorbitol dehydrogenase
119
Flatulence and diarrhea after ingestion of dairy products
Lactose intolerance
120
Enzyme deficiency: Lactose intolerance
Lactase deficiency
121
Treatment of Lactose intolerance
Reduce consumption of milk while eating yogurts and cheeses, broccoli
Use of lactase-treated products or lactase pills
122
Intolerance of ingested sucrose
Sucrase isomaltase complex deficiency
123
Treatment of Sucrase isomaltase complex deficiency
Dietary restriction of sucrose
124
Alternative pathway for oxidation of glucose in the liver
Uronic Acid Pathway
125
Main pathway for production of glucoronic and iduronic acid
Uronic acid pathway
126
Not possible for guinea pigs and primate because of absence of
L-gulonolactone
127
Essential component of glycosaminoglycans
Glucoronic Acid
128
Also known as Hexose Monophosphate Shunt
Pentose Phosphate Pathway
129
Substrate of Pentose Phosphate Pathway
Glucose 6 phosphate
130
End products of Pentose Phosphate Pathway
NADPH
| Ribose 5 phosphate
131
Required for biosynthesis of nucleotides
Ribose 5 phosphate
132
Rate limiting step of PPP
Glucose 6 phosphate dehydrogenase
133
Most common disease producing enzyme abnormality in humans
Glucose 6 phosphate dehydrogenase deficiency
134
Precipitating factors: Glucose 6 phosphate dehydrogenase deficiency
Infections (most common)
Drugs (sulfonamides, primaquine, chloramphenicol)
Fava beans
135
G6PD pathognomonic sign
Heinz bodies
| Bite cells
136
Deficiency in NADPH oxidase
Chronic Granulomatous Disease
