Exam 4 Flashcards
(123 cards)
1
Q
What stimulates the Pentose Phosphate Pathway?
A
Glucose-6-phosphate and NADP+
2
Q
What inhibits the Pentose Phosphate Pathway?
A
6-Phosphoglucono lactone and NADPH
3
Q
What is the rate limiting enzyme for the Pentose Phosphate Pathway?
A
Glucose-6-Phosphate Dehydrogenase
4
Q
What is the cellular location for the Pentose Phosphate Pathway?
A
Cytoplasm/Cytosol
5
Q
What are the other names for the Pentose Phosphate Pathway?
A
Hexose monophosphate pathway and Hexose monophosphate shunt
6
Q
What is the cellular location for the Electron Transport System (ETS)?
A
Inner membrane of the mitochondria
7
Q
What is the cellular location for Ketogenesis?
A
Mitochondrial Matrix
8
Q
What is the cellular location for Beta Oxidation?
A
Mitochondrial Matrix
9
Q
What is the cellular location for Glycogenesis?
A
Cytosol
10
Q
What is the cellular location for Glycogenolysis?
A
Cytosol
11
Q
What is the cellular location for Fat Synthesis?
A
Cytosol
12
Q
What is the cellular location for Cholesterol Synthesis?
A
Cytosol
13
Q
What is the cellular location for Glycolysis?
A
Cytosol
14
Q
What is the cellular location for Gluconeogenesis?
A
Cytosol or Mitochondrial Matrix
15
Q
Which amino acids are used in the creation of Purines?
A
Guanine and Adenine
16
Q
Which amino acids are used in the creation of Pyrimidines?
A
Thymine and Cytosine : DNA
Uracil and Cytosine : RNA
17
Q
What are the fates of NADPH?
A
R: Reductive biosynthesis
D: Detoxification
R: Respiratory bursts
A: Antioxidant regeneration
18
Q
What is involved in Reductive Biosynthesis?
A
NADPH donates electrons to help build:
- Fat CRDR reactions
- Cholesterol
- Steroid Hormones
- Bile Salts
19
Q
What steps are involved in the Fatty Acid Synthase reaction?
A
C: Condenses (adds malonyl CoA)
R: Reduces (with NADPH)
D: Dehydrates
R: Reduces (With NADPH)
20
Q
What is involved in Detoxification?
A
- Makes toxins water soluble
- adds H2O and O2
- Excrete toxins in urine
- Cytochrome P450 in endoplasmic reticulum of LIVER
- adds hydroxyl group compounds
21
Q
What is involved in Respiratory Bursts?
A
- Creates “harsh chemistry” to kill non-self bacteria
- WBC take in more O2
- O2 plus electrons (from NADPH) make reactive molecules
- sequestered in vesicle; bacteria dies
22
Q
What are the steps involved in “Harsh Chemistry”?
A
- OXIDASE: electrons to O2; forms Superoxide
- SUPEROXIDE DISMUTASE: forms H2O2
- MYELOPEROXIDASE: forms HOCl “Hypochlorous Acid”
23
Q
What is involved in Antioxidant Regeneration?
A
- Adds electrons from NADPH to antioxidents which restores their reducing power
- protects body from free radicals
24
Q
What are the 3 main antioxidant enzymes?
A
Superoxide dismutase, Catalase, and Glutathione peroxidase
25
What is the cellular location for superoxide dismutase?
Extracellular, cytoplasm, mitochondria
26
what does superoxide dismutase require?
Zinc, copper, and manganese (in mitochondria)
27
What is the function of superoxide dismutase?
Quenches (eliminates) O2 and produces H2O2
28
What is the function of Catalase?
Quenches H2O2 and produces water and oxygen
29
What is the cellular location for catalase?
cell peroxisomes
30
what does catalase require?
iron
31
What is the function of Glutathione peroxidase?
Quenches H2O2 and produces water
32
What is the cellular location for glutathione peroxidase?
Cytosol and mitochondria
33
How is most H2O2 quenched?
via Glutathione Peroxidase (GPX)
34
What makes up a nucleoside?
Base + Sugar
35
What makes up a nucleotide?
Base + Sugar + Phosphate
36
What does glutathione peroxidase require?
Selenium
37
What are some characteristics of Oxidative reactions?
Irreversible, produces NADPH
38
What are some characteristics of Non-oxidative reactions?
Reversible, produces Ribose-5-phosphate, (interconversion of sugars)
39
What is unique about the Pentose Phosphate Pathway (PPP)?
No ATP is produced or consumed!
40
What are the 4 individual steps of the PPP?
D: Dehydrogenation of G-6-P
H: Hydrolysis of 6-phophogluconolactone
O: Oxidative decarboxylation (produces ribulose-5-phosphate)
I: Isomerization (Ribulose-5-P to Ribose-5-P)
41
What 4 compounds are related to Ribose sugar?
Adenosine
Guanosine
Cytidine
Uridine
42
What compound is related to 2-deoxyribose sugar?
thymidine
43
What is the free base for Inosine?
Hypoxanthine
44
What is involved in a salvage pathway?
Recycling preformed bases from "old" nucleotides and adding a ribose unit (PRPP)
45
What is involved in the De Novo (from scratch) synthesis pathway?
Purines - start with ribose and add piece by piece
| Pyrimidines - form base piece by piece and add to ribose
46
What does PRPP stand for?
5-phosphoribosyl-1-pyrophosphate ("activated pentose")
47
Which pathways require PRPP?
Both salvage and De novo (from scratch) for purines and pyrimidines
48
What is used to create PRPP?
Ribose-5-Phosphate
49
The De Novo synthesis pathway requires?
Tetrahydrofolate Methyl donor
50
What is the location of the Purine De Novo synthesis pathway?
cytosol of liver
51
What is the rate limiting enzyme for the purine De Novo synthesis pathway?
Xanthine Oxidase
52
What donates nitrogen to the purine synthesis pathway?
aspartate
glutamine
glycine
53
What pathway does non-hepatic purine synthesis use?
Salvage pathway
54
What is produced upon breaking down nucleotides into bases during the salvage purine pathway?
Hypoxanthine
55
What enzyme is required for the purine salvage pathway?
Phosphoriboyltransferase (PRT)
56
What enzyme is involved in the De Novo reduction of ribonucleotides?
Ribonucleotide reductase
57
What inhibits the committed step of De Novo synthesis?
hypoxanthine
58
What enzyme produces Uric Acid?
Xanthine Oxidase
59
What inhibits Xanthine Oxidase?
Allopurinal
60
What is the accumulation of excess Uric acid called?
Gout
61
What is the increased concentration of uric acid in the blood called?
hyperuricemia
62
What is the precursor to Uracil, Thymidine, Cytosine?
Uridine monophosphate
63
What is a carbon donator for Purine synthesis?
Folic Acid
64
What is the cellular location for Pyramidine synthesis?
Cytosol
65
What is the rate limiting enzyme for Pyramidine synthesis?
CAD (HUGE LONG NAME)
66
What is a nitrogen AND carbon donor for pyramidine synthesis?
Aspartate
67
What is the starting material for pyrimidine synthesis?
bicarbonate (HCO3)
68
What is special about CAD?
It is a multi enzyme complex (Goes in order)
69
The regulatory step of pyrimidine synthesis is inhibited by what?
UTP (it is an end product)
70
The regulatory step of pyrimidine synthesis is stimulated by what?
PRPP
71
What does the first step of pyrimidine ring formation involve?
Bicarbonate and glutamine
72
what does the second step of pyrimidine ring formation involve?
aspartate
73
UMP is phosphorylated to form what during CPT Synthesis?
```
UDP TMP (Thymidine monophosphate)
UTP CPT (Cytidine Triophophate)
```
74
A direct reduction of the secondary hydroxyl group of Adenine, Guanine, and Uracil is performed by what enzyme?
Ribonucleotide reductase
75
Thymidine has a unique pathway that uses what two enzymes?
Ribonucleotide reductase and Thymidylate synthase (main enzyme)
76
The thymidine pathway in Pyrimidine synthesis requires what?
Folic Acid and NADPH
77
The pyrimidine salvage pathway can transfer nitrogen to form what compound?
Glutamate (used in FA synthesis or Krebs)
78
What is the primary pathway for the synthesis of Thymine and Uracil?
Salvage pyrimidine pathway
79
What enzymes does the pyrimidine salvage pathway require?
Nucleoside Phosphorylase or Nucleoside Kinase
80
What is the nucleotide that is not salvaged in humans?
Cytosine
81
Antibacterial:
| Fluorocytosine is converted to fuorouacile which is toxic.
KNOW IT...idk
82
What stimulates Glucose-6-Phosphate Dehydrogenase?
Glucose-6-Phosphate
83
How much ATP is used in the PPP?
0
84
A base + sugar + phosphate represents what?
nucleotide
85
Name the Purine nucleotides:
Adenine (DNA and RNA)
| Guanine (DNA and RNA)
86
Name the Pyrimidine nucleotides:
Cytosine (DNA and RNA)
Thymine (DNA)
Uracil (RNA)
87
Myeloperoxidase produces what?
Hypochlorous Acid (HOCl)
88
What cofactor is required for Superoxide Dismutase in the mitochondria?
manganese (specifically in the mitochondria, zinc and copper are elsewhere)
89
Which cofactor is required for catalase?
Iron
90
What is a big carbon donor for purine synthesis?
Folic Acid (tetrahydrofolic acid)
91
Excess Uric acid accumulation can lead to what?
Gout
92
What inhibits xanthine Oxidase?
Allopurinal
93
What is the cellular location of Carbamoyl phosphate?
Mitochondrial Matrix
94
What is the coenzyme for thymidylate synthase?
Folic acid
95
Can you excrete ethanol directly from the body?
No
96
What are the enzymes involved in ethanol oxidation?
Alcohol dehydrogenase (ADH)
MEOS-> Cytochrome P450
Acetylaldehyde dehydrogenase
Catalase (in presence of hydrogen peroxide)
97
If ADH is saturated, what happens to extra ethanol?
ethanol is transferred and processed by MEO (end product acetylaldehyde via acetylaldehyde dehydrogenase)
98
What is the cellular location of alcohol dehydrogenase?
cytoplasm of hepatocytes
99
What does Alcohol dehydrogenase require?
NAD+ (produces NADH)
100
What can MEOS oxidize?
```
Ethanol
Fatty acids
Aromatic hydrocarbons
steroids
barbituate drugs
```
101
what is the location of MEOS?
endoplasmic reticulum
102
Where does MEOS get electrons?
NADPH
103
Can we make more MEOS enzymes?
Enzymes are "inducible". higher alcohol concentration induces the synthesis of more MEOS enzymes
104
What is the end product of both ADH and MEOS?
Acetylaldehyde (30x more toxic than ethanol)
105
What condition can acetylaldehyde cause?
perivenular fibrosis
106
Which two pathways produce NADH directly?
ADH and Acetaldehyde dehydrogenase
107
Does MEOS produce NADH?
not directly
108
What does more NADH mean?
Less fat burning
more fat synthesis and TAG
KREBS inhibition
More lactic acid
109
The presence of NADH stimulates what pathways?
FA synthesis
Lactic Acid
TAG synthesis
110
The presence of NADH inhibits what pathways?
```
FAT Burning (OHOT)
Krebs Cycle (IASM)
Glycolysis (G3P)
```
111
What does the alcohol metabolism pathway do to lactate production?
Stimulates it. Can cause lactic acidosis so it is sent to other pathways. (hypoglycemia and Ketoacidosis)
112
What major element of the alcohol metabolism pathway does not produce NADH?
MEOS (isocitrate dehydrogenase does but different pathway)
113
What stimulates ADH?
Ethanol
114
What amino acid is necessary to synthesize a primary bile salt?
Glycine
115
What is the required protein for initiating glycogen synthesis?
glycogenin
116
What kind of dose from fructose metabolism is necessary to increase liver glycogen synthesis?
Low dose
117
```
Which is not an irreversible step of glycolysis?
A Hexokinase
B Pyruvate Kinase
C Phosphoglycerate kinase
D Phosphofructokinase
```
C Phosphoglycerate kinase
118
What is the required coenzyme for pyruvate carboxylase?
Biotin
119
What happens to lactate during the cori cycle?
Lactate is transported to liver
120
Is gluconeogenesis stimulated or inhibited by acetyl coa?
stimulated
121
What is required for GMP synthesis from IMP?
ATP
122
What is the cellular location of CAD?
Cytosol
123
What is the common base for degradation of all purines?
Xanthine
