Chapter 8: Nucleotides Flashcards
(103 cards)
1
Q
DNA and molecular biology
A
The science that deals with the nucleic acids.
2
Q
RNA
A
Ribnucleic acid
3
Q
DNA
A
Deoxyribonucleic acid
4
Q
What is the structural unit if nucleic acids?
A
Nucleotides
5
Q
What are nucleic acids formed of?
A
Polynucleotides
6
Q
Nucleotides are formed of
A
Nitrogenous base + pentose + phosphate.
7
Q
Nucleoside
A
Nitrogenous base + penstose
8
Q
Nitrogenous base is formed of
A
- Purines.
- Pyrimidine.
9
Q
Purines
A
- Adenine.
- Guanine.
10
Q
Pyrimidine
A
- Cytosine.
- Uracil.
- Thymine.
11
Q
Pentose is formed of
A
- Ribose.
- Deoxyribose.
12
Q
Ribose
A
In RNA.
13
Q
Deoxyribose
A
In DNA
14
Q
Uracil site
A
RNA
15
Q
Thymine site
A
DNA
16
Q
Cytosine site
A
Both RNA and DNA
17
Q
Cytosine
A
2 oxy 4 amino Pyrimidine
18
Q
Deamination of cytosine
A
Uracil
19
Q
Uracil
A
2, 4 Di oxy Pyrimidine
20
Q
Thymine
A
5 methyl uracil
21
Q
Pyrimidines
A
Major Pyrimidines:
1. Uracil.
2. Cytosine.
3. Thymine.
Minor Pyrimidines:
1. Dihydro uracil.
2. Methyl cytosine.
3. Hydroxy methyl cytosine.
22
Q
Purines
A
Major Purines:
1. Guanine.
2. Adenine.
Minor Purines:
1. N7 methyl guanine.
Oxy purines:
1. Hypoxanthine.
2. Xanthine.
3. Uric acid.
Methylated Purines:
1. Caffeine.
2. Theophylline.
3. Theobromine.
23
Q
Adenine site
A
Both RNA and DNA
24
Q
Guanine site
A
Both RNA and DNA
25
Guanine
2 amino 6 oxy purine
26
Adenine
6 amnio purines
27
Hypoxanthine site
No present in DNA and RNA
28
Xanthine site
Not present in DNA or RNA
29
Hypoxanthine and xanthine formation
Formed during synthesis or catabolism of major purines.
30
Uric acid
The end product of the purine catabolism.
31
Uric acid exertion
It is excreted in urine.
32
Normal blood level amount of Uric acid
3-7 mg/dl.
33
If the Uric acid in blood increases what would happen?
It leads to gout (hyperuricemia).
34
Deamination of adenine
Hypoxanthine
35
Hypoxanthine
6 oxy purine
36
Xanthine
2, 6 di oxy purines
37
Uric acid
2,6,8 tri oxy purines
38
Caffeine , theophylline, theobromine site
Not present in DNA or RNA
39
Caffeine
In coffee (1,3,7 tri methyl xanthine).
40
Theophylline
Present in tea (1,3 di methyl xanthine).
41
Theobromine
Present in cocoa (3,7 di methyl xanthine).
42
End product of methylated purines
Not Uric acid
43
Are methylated purines contraindicated in cases of gout?
No
44
What do methylated purines act as?
The act as CNS stimulants and diuretics.
45
Nucleoside
C1 in pentose is attached to N1 (base is Pyrimidine) or N9 (base is purine) by N-glycosidic bond.
46
Nucleotide
Phosphate is attached to C5 of pentose (5 hydroxyl group) by phosphate ester bond.
47
Examples of nucleosides
1. Uridine.
2. Deoxy adenosine.
48
Examples of nucleotides
1. Uridine mono phosphate.
2. Deoxy adenosine mono phosphate.
49
Carbon atoms of pentose are named?
1’ 2’ 3’ 4’ 5’
50
If the nucleotide contains ribose
Ribonucleotides
51
If the nucleotide contains Deoxy ribose
Deoxy ribonucleotides.
52
What are nucleosides or nucleotides names according to?
Their nitrogenous base.
53
Adenine nucleoside
Adenosine
54
Adenine nucleotide
1. Adenosine mono phosphate.
2. Adenylic acid.
55
Guanine nucleoside
Guanosine
56
Guanine nucleotide
1. Guanosine mono phosphate.
2. Guanylic acid.
57
Xanthine nucleoside
Xanthosine
58
Xanthine nucleotide
1. Xanthosine mono phosphate.
2. Xanthylic acid.
59
Hypoxanthine nucleoside
Inosine
60
Hypoxanthine nucelotide
1. Inosine mono phosphate.
2. Inosinic acid.
61
Uracil nucleoside
Uridine
62
Uracil nucleotide
1. Uridine mono phosphate.
2. Uridylic acid.
63
Thymine nucleoside
Thymidine
64
Thymine nucleotide
1. Thymidine mono phosphate.
2. Thymidylic acid.
65
Cytosine nucleoside
Cytidine
66
Cytosine nucleotide
1. Cytodine mono phosphate.
2. Cytidylic acid.
67
Free nucleotides and nucleosides
1. Adenine free nucleotides.
2. Guanine free nucleotides.
3. Cytosine free nucleotides.
4. Uracil free nucleotides.
68
Adenine free nucleotides
1. AMP (adenosine mono phosphate), ADP (adenosine di phosphate), ATP (adenosine Tri trinphosphate).
2. 3’, 5’ cAMP (cyclic adenosine mono phosphate).
3. SAM (S-adenosyl methionine) or active methionine.
4. PAPS (3’ phospho adenosine 5’ phospho sulfate).
5. Coenzymes containing adenine.
69
What is ATP?
Currency of energy inside the body.
70
High energy bonds
Bond between a-B and B-y.
71
ATP is a source of energy in all types of work:
1. Mechanical: muscle contractions.
2. Electrical: nerve impulse.
3. Chemical: anabolic reactions.
4. Cell membrane transport.
72
What is cAMP?
AMP at which the phosphate attached to 5’ OH and 3’ OH by phosphodiester bond.
73
What is cAMP formed of?
3’, 5’ cAMP os formed of ATP by adenylate cyclase.
74
What is cAMP broken down by?
Phosphodiesterase
75
Importance of cAMP
They act as hormone’s 2nd messenger (signal transduction).
76
Many enzymes involved in metabolic pathways are regulated by?
Phosphorylation and dephosphorylation
77
Phosphorylation of enzymes
1. Hormone binds to receptor in cell membrane.
2. Activation of G protein.
3. Activation of adenylate cyclase.
4. Increase in cAMP.
5. Activates protein kinase A.
6. Phosphorylation of the enzyme.
78
Dephosphorylation of enzymes
1. By the enzyme (protein phosphatase).
2. Protein phosphatase is activated by insulin and inhibited by cAMP.
3. Phosphodiesterase breaks down cAMP into 5’ AMP and activated by insulin.
79
What is adenylate cyclase activate by?
Glucagon and adrenaline.
80
What is the active form of glycogen synthase?
Dephosphorylated
81
Glycogen phosphorylase kinase active form
Phosphorylated
82
What is inactive protein kinase A formed of?
It is a tetramer formed of:
1. 2 regulatory subunits (R).
2. 2 catalytic subunits (C).
Each R subunits release the 2 catalytic subunits which are active and catalyze phosphorylation of the enzyme.
83
SAM
Free nucleoside.
84
SAM is formed of?
Formed in the body from methionine and ATP.
85
SAM function
OST important methyl donor in the body.
86
Transmethylation of SAM results in?
SAH (S-adenosyl homocysteine).
87
PAPS function
Sulfate donor for synthesis of GAGs and Sulfolipids.
88
Coenzymes containing adenine
1. Nicotinamide (vitamin B3) containing nucleotides.
2. Flavin (vitamin B2) containing nucleotides.
3. Con enzyme A also called CoASH (containing Vitamin B5).
89
Nicotinamide
1. NAD (Nicotinamide adenine di nucleotide).
2. NADP (Nicotinamide adenine di nucleotide phosphate) converted to NADPH+H+.
3. NAD converted NADH+H+.
90
Flavin
1. FMN (flavin mono nucleotide).
2. FAD (flavin adenine di nucleotide).
3. Both act as hydrogen carriers.
4. FMN is converted to FMNH2.
5. FAD is converted to FADH2.
91
CoASH
1. Acts as acyl group (FA) carrier as in acetyl CoA, Propionyl CoA, and Succinylcholine CoA.
2. Active group is SH (thiol) group of thioethanolamine.
92
Guanine free nucleotides
1. GMP, GDP, and GTP (guanosine mono, di, and tri phosphate).
2. cGMP (3’, 5’ cyclic guanosine mono phosphate).
93
cGMP
Phosphate is attached to 5’ OH and 3’ OH by phsophodiester.
94
How is cGMP formed?
It is formed from GTP by guanylate cyclase.
95
How is cGMP broken down?
It is broken down by Phosphodiesterase.
96
cGMP importance
1. Act as hormones 2nd messenger (may antagonize cAMP).
2. Mediator for vasodilators (cause smooth muscle relaxation) as NO (nitric oxide).
97
Cytosine free nucleotides
1. CMP, CDP, and CTP.
98
CDP function
Acts as a carrier for:
1. Ethanolamine.
2. Choline.
3. DAG.
Used for phospholipid synthesis.
99
Uracil free nucleotides
1. UMP, UDP, And UTP.
100
UDP function
Carrier for:
1. Glucose.
2. Galactose.
3. Glucuronic acid.
101
UDP glucose
Synthesis of:
1. Glycogen.
2. Glycoprotein.
3. Glycolipids.
102
UDP galactose
Synthesis of:
1. Lactose.
2. Glycoproteins.
3. Glycolipids.
103
UDP glucuronic acid
For synthesis of GAGs ans detoxification of:
1. Steroids.
2. Bilirubin (bile pigment).
3. Drugs.
