Biochem Review Flashcards
(123 cards)
1
Q
Isoprenoids
Made from what?
Can be formed into what?
Components of what?
A
- acetyl coA
- steroids (cholesterol), vitamins, and coenzyme Q
- Membranes and bile
2
Q
What does bile contain and what can form if the levels are thrown off?
A
Cholesterol and salts
- can cause gallstones, malabsorption (steatorrhea) and fat-sol vitamin def
- helped w/ oral chenodeoxycholic acid
3
Q
What are the essential AAs?
A
Pvt Tim Hall
Phenylalanine, Valine, Threonine, Tryptophan, isoleucine, methionine, Histidine, Leucine, Lysine
4
Q
Hair has what that can be manipulated by curling and heating?
A
Keratin w/ high cysteine disulfide bonding
5
Q
What type of reaction is delta G when neg or pos?
What is Gibbs FE equation
A
RTln(Keq)—prod/reactants
- exergonic, spontaneous, E producing
+ endergonice, non-spon, E consumed
The ability to do work
6
Q
What is the bicarbonate buffer system equation (pH, etc)
A
bicarb+ H – H2CO3 – CO2 + Water
Acidosis= left shift = +acid (ketone bodiess, lactate) or -biocarb (diarrhea, weak kidneys)
Alkalosis= right shift= +strong base (antacid) or -acid (vomit) or Hyperventilate
7
Q
Oxidation vs Reduction
A
Ox- lose Electrons (gain H)
Red- gain E (lose H)
8
Q
Cofactor vs Coenzyme
A
-metal ions
(type of cofactor)- vitamin derivative
9
Q
Cosubstrate vs prosthetic
A
temporary (NAD+)
-permanent association (FAD or heme)
10
Q
The alpha keto-DH complex involves what vitamine derivatives?
A
Lipoic acid, B3 (niacin), B5 (panth), B1 (thy)
11
Q
What affects enzyme activity? factors
A
Temp: doubles every 10 deg C (untill denatured)
pH: between 4-8 (pepsin in gastric)
12
Q
Hydrogen/ K+ ATPase
Where found?
What direction does it pump
What are inhibitors prescribed for?
A
Parietal cells lining gastric lumen
- H+ into the lumen…lowers pH (acidic) combines with Cl to form HCl- can cause hypochlorhydia– reduces reabsorption of nutrients
- Omeprazole, etc to increase pH in Heartburn, indigestion, etc
13
Q
Competitive Inhibition
Noncompeitive
Uncompetitve
A
C: compete with sub site… need more sub to overcome (increased Km)
N: binds to E and ES complex…. decreased Vmax
U: Binds to ES complex only… Decreased Vmax and Km by same factor
14
Q
What does lead poisoning cause (symp) and what is used to treat?
A
Chelating agents
abdom pain, sideroblastic anemia, irribility, headaches, impaired NS
15
Q
What is sideroblastic anemia?
A
Inability of bone marrow to produce normal rbcs
16
Q
What are isozymes?
A
Enzymes with the same catalytic function, but different primary sequence (different biological properties)
(Troponin cTn, CK-MB, LDH1) all MI markers
17
Q
What enzymes are found in blood for these diseases? Bone Obstructive liver Prostatic cancer Acute pancreatitis Muscular dystrophy Liver disorder
A
Alkaline phosphatase
-Sorbitol DH or Lactate DH LDH1
- Acid phosphatase
- Amylase
- Aldolase and ASH
- CK-MM
18
Q
Amphipathic means?
A
Both hydrophobic and hydrophilic
phospholipid bilayer
19
Q
Whats the difference btw these phospholipids?
Glyceropholspholipids
Sphingolipids SL
A
G: glycerol backbone + phos and 2 fattys esterfied to bb
SL: sphingosine backbone + phosphorylcholine and long chain fatty
sphingolipids, has a long alkyl group connected at C1 and a free amine at C2, as a backbone.
20
Q
What is a glycolipid?
A
found on membrane (outer leaf)
Sphingosine backbone w/ oligosacc residues and fatty acid attached
21
Q
Membrane proteins:
Integral
Peripheral
Lipid Anchored
A
embedded and stabilized with hydrophobic intereactions
loosely bound w/ electrostatic interaction
tethered via covalent bonds to lipids
22
Q
Carb shell of membrane that provides protection, cell adhesion, and cell identification?
A
Glycocalyx
23
Q
What is the melting temp Tm of a membrane?
A
Temp where it switchese from fluid to rigid
24
Q
What kinds of molecules utilize facilitated diffusion? (passive)
A
large and uncharged
- need a facilitator (proteins)
- ion channels or transporters (voltage gated Na… or GLUT1)
- greatly increase transport rate
25
What are common ligands for ligand gated- ion channels?
| Whats an example? and What are two inhibitors used to treat?
-neurotransmitters or hormones
-Glutamate receptor
The antagonists of GR (Mimantine/Namenda) used to treat Alzheimers
26
What does Tetradotoxin do and where can it be found in wild?
-binds to Na+ channel and inhibits neurotransmission
Puffer fish
Same function as topical anesthetics
27
P type ATPase
vs
ABC transporter
both active transport
ATPase: Primary: use ATP hydrolysis to drive
- covalent bond with phosphate
- occurs on conserved Asp residue
- conformational changes occur (Na/K ATPase, Ca-ATPase
ABC: smaller molecules, use ATP hydro, but protein is not phosphorylated
-pathogens can upregulate, leading to drugs being pumped out too quickly to have effect
28
Examples of secondary transporters:
| coupled to primary
Na/Ca exchanger: NCX: antiporter.. A in-- B out
Lactose permease: Symporter: A and B in
Mito Ca transporter: Uniporter: A in -- A out
29
What does the Sodium-Glucose transporter SGLT1 do? where does it happen?
What drugs relate to it?
Happens in the small intestine and renal tubules
- unidirectional movement of Na+ and Glu
- Na occurs down its gradient and provides E to move Glu up its gradient (secondary transporter)
- Na+ gradient reset by the Na/K-ATPase
Invokana and Farxiga
-Inhibitors= keep glucose in intrestines--> more released in urinations--> helps lower blood pressure and weight loss
30
Flowing in the NCX? which is an antiporter of course
facilitated by integral membrane proteins
3 Na down gradient in..... and 1 Ca against gradient out
31
Transporters involved with monosaccharide transport
Which side of enterocyte and what category of transporter?
SGLT1
GLUT2
GLUT5
Na/K ATPase
S: on apical side (lumen of small intestine)
- Glu, Gal, Na+ all come in
- secondary active
G2: on basolateral side (bloodstream)
- Glu, Gal, Fru leave to blood
- fd
G5: on apical side
- Fru in
- facilitated diff
Na/K: basolateral side (blood)
- 3Na in to blood....2K out of blood--> enterocyte
- primary active
32
BMI calculation
Weight/height^2
| Kg/m2
33
Percentage of cals from protein, fats, and carbs?
10-15% protein
20-35% fats
rest carbs
and more omega 6 than 3 (5-10% and 1%)
34
Type O blood contains which Ag and what Abs?
H antigen
| AntiA and B antibodies (found in the plasma)
35
Where are Ags and Abs found in blood?
on rbcs
in the blood plasma
36
What are the drugs Ouabain and Digoxin? What are they used for and what do they do?
Cardiac Glycosides (contraction inducing)
- Inhibits the Na/K ATPase in cardiac myocytes--> increase in Na+
- ->impairs NCX that's coupled to ATPase---> increase in Ca2+ in the sarco reticulum
- Inc contractile force
- Used to treat congestive heart failure, atrial dibrillation, dysrhythmias.... they are very potent! Have been used to coat arrords and rat poisons
Digitoxigenin: slowly reduces the resting potential of neurons to 0
- can lead to confusion, vision issues, delirium
- jumpstarts the heart but affects the brain
37
During a sprint, what path is utilized for ATP to outpace O2 delivery?
Lactate path via glycolysis (which doesn't need O2)
The resulting Pyr can be oxidized under Aerobic conditions to produce much more ATP
38
What is the only fuel of red blood cells and brain (non-starving?
Glucose
39
Where does Gluconeogenesis occur?
Liver
| and some in kidney cortex
40
```
Glucose Transporters
GLUT:
1
2
3
4
5
```
1: Ubiquitous (in many cells ie. brain, cornea, placenta, cancer cells) but high in rbcs especially
- High affinity
2: Main transporter in liver (and pancreas)
- low affinity
3: Main transporter in neurons
- high affinity
4: Present in skeletal muscle, heart, adipose tissue
- medium affinity
- Insulin dependent
- -sequestered in cell vesicles--> insulin signals fusion to membrane-->then increases glucose uptake (promoted by exercise)
5: On apical side of enterocyte (intestinal)
- Lets fructose in into enterocyte
Km is inverse to affinity
41
Where is Glucokinase present? and what promotes its translocation to and from the nucleus from the cytoplasm?
Liver and Pancreatic Beta cells
F6P to nuc....Glu increase from nuc-->cyto
42
Rate limiting enzyme of glycolysis?
Activated by what? Inhibited by what?
Coupled with what (bifunctional enzyme) in Gneogenesis?
PFK1
+ AMP, F2,6BP
- ATP, Citrate
F1,6-BPase (phosphatase)
43
What activates and inhibits Pyr Kinase?
+insulin, F1,6BP
stim dephosphorylation of PK (activated)
-Glucagon, Alanine, ATP
stim cAMP phosphorylation of PK (inhibited)
44
What other paths is G6P used in?
```
PPP (Ribose and NADPH)
Galactose metabolism
Glycogen Synthesis
Glycolysis (Pyr)
Gluconeogenesis (Glu)
```
45
What are some precursors of Pyruvate?
| What are some things made from pyruvate?
```
Pre:
Glucose
Trp
Thr
Ala
```
Makes:
Acetyl CoA (Pyr DH complex)-- Aerobic fed
Alanine (Ala Aminotransferase)--Anaerobic/Aerobic fed
Oxaloacetate (Pyr Carboxylase)--Aerobic fasting
Lactate (lac DH)-- Anaerobic
46
What do defects in glycolytic enzymes generally cause?
What do they most impact?
What are some of the enzymes?
- Hemolytic anemia
- RBCs (lack mitochondria)
- PG Isomerase, Triose P Isomerase, Aldolase A
- ---PKinase (95% of defects)
47
Where does Gluconeogenesis occur?
| What are the major precursors?
Liver, kidney, small intestine
Lactate, amino acids, and glycerol
48
Where is Pyruvate Carboxylase PC found?
What does it form? and what step follows?
What is its cofactor?
What activates it?
The mitochondria
Oxaloacetate--> PEP Carboxykinase - PEP
Ox reduced to Malate (M DH) and transported through Malate Shuttle in between
Biotin B7
Acetyl CoA and Cortisol
49
What is the rate-limiting step of Gluconeogenesis?
F1,6 Bisphosphatase
Act by Cortisol and Citrate
- by AMP and F2,6-BP
50
Where is glucose -phosphatase located?
| What are its components?
Endoplasmic Reticulum on liver, kidneys, SI, pancreas
GLUT7 + catalytic unit, and Pi antiporder
51
What does the Cori cycle do?
Links the lactate in anaerobic glycolysis in rbc and muscle to Gneo in liver
Prevents lactate accumulation, regenerate glucose
Lac-->blood-->liver------>glu-->blood-->muscle--Pyr--> back to lac
52
What are precursors of gluconeogenesis?
```
Fructose--DHAP and G3P
Galactose
Glycogen
Glycerol
Propionate
Lactate--Pyr
Alanine--Pyr
AAs
```
53
The Polyol Pathway turns Glucose to Fructose. What are the two enzymes used and what is the intermediate between G and F? Where does this occur in the body?
Aldose reductase-->Sorbitol-->Sorbitol DH-->Fruc
In Hepatocytes (liver), Ovaries, seminal vesicles (sperm
Accumulation can occur in kidneys, lens, retina, schwann cells
54
When Fructose is metabolized, what two paths can it take? and What critical Glycolysis step can it bypass (making it a faster process)?
1. can turn to F6P by Hexokinase
2. can turn to DHAP or G3P by FKinase->F1P-->Aldolase B--product
Bypasses PFK1 RL*
55
Why can excess Fructose consumption be bad?
Bc it bypasses PFK1, too much pyruvate can accumulate--> turning to TAGs and fatty liver/adipose... process happens in an unregulated fashion
High Fruc Corn Syrup
56
What is the rate limiting enzyme in Galactose Metabolism and where does the end product insert into Glycolysis?
Glucose 1P Uridyltransferase GALT
G6P
Makes UDP-Galactose used to synthesize Lactose in mammary glands and Glycolipids/proteins
57
What causes Galactosemia?
deficiency in GALT--accumulation of galactitol
| def. in Galactokinase
58
What does the Pentose Phos Path produce?
What are its byproducts?
What is the RL Step?
Ribulose 5-P...or continues onto non-ox step to make R5P and various glycolytic intermediates like G3P, F6P
Makes 2 NADPHs in the Ox irreversible step
G6P DH (the first step)
59
What does a deficiency in G6P DH cause? in what population? and what does NADPH regenerate as an antioxidant?
hemolytic anemia (lack of NADPH)
African Americans
NADPH-->glutathione GSH...detoxifies H2O2
60
What would cause high NADPH demand?
| How about Ribose 5P?
- increased biosynthesis, Lactating mammary, phagocytosis, lung and liver tissue (non-ox phase favored for products)
- Cells rapidly dividing (ox phase favored in PPP)
61
Where is glycogen stored?
Liver (blood glu regulation) and muscle (physical activity reservoir) as granules
62
What is the RL enzyme of Glycogenesis and Glycogenolysis?
| what cofactor is used in the breakdown?
Gly Sythase! (dephos form +) Glucosyl 4,6 Transferase for the branching part
Gly Phosphorylase! (phos form +) w/ vit B6 (pyridoxal phosphate) Debranching enzyme w/in 4 residues
63
When is glycogen breakdown favored?
Low BG, high Glucagon (fasting- doesn't act on muscle), high Ca+ levels during exercise (high AMP)
64
An antigen that evokes a specific immune response-
Immunogen
65
An Ag inducing an immunologic tolerance-
Tolerogen
66
In the Pyruvate DH complex (pyr-ACoA), what coenzyme is used for the E1 complex? and is the complex active in the phos or dephos form?
Thiamine pyrophosphate
-Cleavage of thioester linkages
Dephosphorylated form is active
67
In a pyruvate phosphatase def., (where pdc is always inactive-phosphorylated), glucose generally becomes what instead of ACoA?
What should be restricted in a patient's diet?
Which diet is recommended?
Lactate
Alanine
Ketogenic diet
68
What are precursors to Alpha-Ketoglutarate?
Glutamate----
| Gln, Arg, Pro, His GAPH
69
What are precursors to Fumerate?
Phe, Tyr, Asp
| DRP derppp
70
Where does the TCA cycle, Fatty Acid Oxidation, and OxPhos take place?
Mitochondrial Matrix (mostly)
MM
Inner Mito membrane space
71
What does PEP carboxykinase do in relation to diseases?
Promotes cancer cell proliferation... colorectal and breast cancers
72
What does accumulation of Citrate cause (metabolic)?
Shifts toward glycolysis, pyruvate accum, so lactate (and NAD+) increase, which promotes cancer.
Lipid and sterol synthesis also activated (good for cancer)
73
Mutations in what lead to 2-hydroxyglutarate 2HG issues and cancer? What part of TCA cycle does this come from?
IDH1 and 2
Conversion of Alpha Ketoglutarate
74
What is in the urine due to a Fumerase deficiency?
Fumerate associated with succinate and lactate...eventual 2-oxoglutaric aciduria
Death w/in 2 years or life of speech delay
75
What genes are associated with Succinyl-Coa synthetase def
SUCLA2 and SUCLG1'
-associated with mild methlymalonic aciduria
TCA intermediated increased in urine
76
What are the 3 main functions of OxPhos?
1. Transfer e- from nadh and fadh2 to 0xygen
2. est a proton gradient across the inner mito membrane
3. make ATP
77
What two factors constitute the proton motive force drive ATP synth in OxPhos?
ph gradient
| Membrane potential
78
```
What are the inhibitors of OxPhos proteins? and their names?
Complex 1
2
3
4
5
```
1: NADH: ubiquinone Oxidoreductase
- --RAMP- Rotenone, Amytal, Myxothiazol, PiericidinA
2: Succinate DH (TCA)
- --Malonate
3: Cytochrome C reductase
- --Antimycin--> H2O2 buildup from superoxide
4: Cytochrome C Oxidase
- --Cyanide, CO, H2S
5: ATP Synthase
- --Oligomycin
79
What does Dinitrolphenol DNP do?
lowers ATP synthesis
increases fuel consumption, oxygen consump, and heat production
It is an uncoupler--affect Complex 5 but not the rest....
80
Oxphos effiecency is measured by what ratio?
Phosphate:O
81
What happens in the Malate-Aspartate Shuttle in relation to the ETC?
Where is the body does it happen?
GAPDH in glycolysis generates NADH... which transfers a proton to Oxo-->Malate...which travels acros the mito membrane through the shuttle and re-distributes it back to a NAD+--> then enters complex 1 of OxPhos
Heart, liver, and kidney
82
What does the Glycerophosphate shuttle generate and where does that insert into the ETC?
Where is the body is this occuring?
Generates FADH2 from G3P-DHAP of glycolysis
Inserts into Coenzyme Q
Skeletal muscle and brain
83
What is the RL enzyme of FA synthesis?
Where do most of the NADPH molecules come from that are used?
Acetyl CoA Carboxylase (w/ biotin)... forming Malonyl CoA--which inhibits the FA degrade RL step
The PPP
84
What makes up the Fatty Acid Synthase enzyme (turns Mal CoA---> palmitate?
What are the steps that it catalyzes?
2 id dimers, 7 enzymes, and an acyl carrier protein ACP that has a flexible arm
Condensation, Reduction, Dehydration, Reduction
85
Where does elongation of Palmitate (Long chain fa) occur?
How many Fa's at a time?
what is the reducing power?
```
Smooth ER (Malonyl CoA) and Mitochondria (Acetyl CoA)
(as the C donors)
```
2 C at a time
NADPH
86
To desaturate a FA, what enzyme is used? and what does it use to do it?
Acyl CoA Desaturase in the SER
| using NADPH or NADH
87
What can Lenolenic Acid (omega 3) be used to make?
EPA eicosapentanoic acid
| DHA docosahexanoic acid
88
What are omega 3s and 6s good for in the body?
Immune health, Cardiovascular, NS, Vision, Cell membranes
89
Dietary TAGS are broken down where?
Using what key enzyme?
What do they form in the lymphatic system--then blood to get to adipose?
Intestinal cells---first broken down to MAG and FFA in the intest lumen, then remade to TAG in the Icells
FAcyl CoA Synthetase
Chylomicrons
90
What paths work to make Glycerol 3P, which gets input into the FA synth path in the Liver cells?
What do liver TAGs form to join the chylomicrons in the blood?
Glycolysis: to DHAP-->G3P using glycerol 3P DH
Glycerol-->G3P using glycerol kinase
VLDL (Very Low Density Lipoprotein)
91
What enzyme converts the FFAs from chylomicron breakdown and the VLDLs?
Capillary lipoprotein lipase
Then built up to form TAG in adipocytes
92
What are the 3 main enzymes used in the breakdown of TAGS?
What hormones stimulate this?
Hormone Sensitive Lipase HSL
Lipoprotein Lipase LPL
Monoacylglycerol Lipase MAG Lipase
Glucagon, Epi, Norepi
93
Hunger and exercise initiate TAG mobilization, what are key players in the breakdown?
Which is a target for obesity treatment?
cAMP
Protein Kinase A
ATGL
HSL
Perilipin---- Coats lipid droplets, controls the access to HSLipase----this is the target (want to inhibit it)
94
Where is phase 1 (activation) of FA oxidation occuring?
The cytosol---then enters the Inter mem space----then Mito matrix
95
What are the key players in the movement of FA across the Mito membrane?
What are the key enzymes?
What is one main inhibitor of this process? (from FA synthesis)
FA--Facyl CoA via Facyl CoA synthetase
enters intermem space
FACoA--Facyl Carnitine via CPT1 (------by Malonyl CoA)
--uses carnitine
FAC crosses inner membrane via CACT carn-acylcarn translocase
FAC--FAcylCoA via CPalmTransferase II
---carn then moves back to intermem via CACT
96
Which enzyme of FA degradation is the RL step?
| Where is it located?
Carnitine Palmitoyltransferase I
| on the outer membrane--intermem space side
97
What are the 4 basic steps of beta-oxidation (happening inside the mito matrix)?
What enzymes?
OHOT
Oxidation- acyl CoA DH--generates FADH2 for CoQ of ETC
Hydration- Enoyl CoA Hydratase
Oxidation- 3-hydroxyacyl CoA DH--generates NADH for complex I of ETC
Thiolysis- Acetyl CoA acetyltransferase--- generates ACoA for TCA
whole processing of Palmitate gives 129 ATP
98
What enzyme catalyzes the first Beta Ox step? What type is related to a specific deficiency?
ACAD
MCAD- 8C FA builds in liver, interferes with urea cycle, inc ammonia levels
Patients depend on glucose for fuel
Leads to secondary carnitine def.
99
In odd number FA chains, What enzymes uniquely are used to degrade?
What product is formed (TCA)
Where do VLCFAs get metabolized?
Propionyl CoA Carboxylase (uses ATP and biotin)
Methylmalonyl CoA Mutase (uses vit B12)
Produces Succinyl CoA----TCA
Peroxisomes
100
Unsaturated FAs require what novel enzymes to be broken down?
Reductase- reduce double bond
Isomerase- move disruptive bond
101
What Amino acids can be precursors to Oxaloacetate?
Aspartate Family
Asp, Asn
Thr, Lys, Met, Ile
102
What Amino acids can be precursors to Alpha ketoglutarate?
Glutamate family
Glu, Pro, Gln, His, Arg
GAPH
103
What amino acids can be precursors to Pyruvate?
Ala, Leu, Val
104
What AAs can be precursors to PEP?
Aromatic family
Tyr, Trp, Phe
105
Which end of a peptide does each type of Proteolytic enzyme work?
Exopeptidase
Endopeptidase
Exo: at the C or N terminus
Endo: within the protein at specific sites (internal bonds)
106
Enterokinase is embedded in the intestinal membrane and activates what zymogen?
Trypsin from Trypsinogen--> activates Chymotrypsinogen and others
107
What are the two purely ketogenic AAs?
What are the 5 keto/gluco AAs?
What are the Essential AAs?
Leu, Lys
PITTT- Phe, Ile, Trp, Tyr, Thr
PVT TIM HLL
108
What do Transaminase reactions always need as a coenzyme?
Pyridoxyl 5' Phosphate
-Vit B6 derivative
Alanine trans ALT----for MI diagnosis
Aspartate Trans AST
109
What disease can Methoinine metabolism relate to?
Homocystinuria
def. in vitamin B6, B12, Folic acid
Cystathionine beta-synthase (with a PLP Pyridoxal Phos cofactor)
110
What is special about Phenyalanine?
| What can it be converted into?
It's glucogenic and ketogenic
Tyrosine and Fumerate (TCA)
111
Why is tyrosine crucial to have? What can it help produce?
Thyroid hormones T3, T4 and endocrine regulation (GABA-neurotransmitter)
Seratonin----Melatonin
Niacin---NAD+ w/ B6 help
112
What is nitrogen removed as in the brain?
| How about in other tissues?
Glu and Gln
Gln and Ala
113
Where is urea formed?
| Where is urea excreted?
Liver and kidneys
Kidneys--urine
114
What is the process of Ammonia removal from the brain?
Alpha keto--->Glu adding NH4 (glutamate DH)
Glu-->Gln adding NH4
Gln shunted to blood and Liver to the urea cycle
115
What is the process of removing excess ammonia from muscle?
Ala-->leaves muscle w/ NH4 from AAs-->Glu
| Drops it off in the liver for urea cycle and then can return as glucose-->glycolysis to pyruvate
116
What two enzymes are used to take NH4 from Ala all the way to the urea cycle in the liver?
ALT aminoacyl transferase
GLDH Glutamate dehydrogenase
Uses glutamate and alpha keto
117
What is the start and end product in purine synthesis?
What is the RL step products?
What is special about the formation of the end products (GTP, ATP)?
What drug is used to inhibit cancer division in the path?
R5P from PPP and either GTP/ATP, dATP, dGTP
PRPP-->PRA using G. PRP Amidotransferase
They cross stimulate each other---form of one stim the other to be formed
Methotrexate-- targets folate enzyme (DHFR)
-prevents oxidation of NADPH, disrupts DNA replication in cancer cells
118
What is the important first intermediate in Pyrimidine synthesis?
Formation of what in the path happens elsewhere before returning to the cytosol?
What Purine Synth intermediate is incorporated toward the end of the path?
What is the RL step?
Carbamoyl Phosphate by CPSII---urea cycle can affect levels leading to hyperammonia w/ orotic aciduria
Orotate in the mitochondria briefly
PRPP (first step in Pur Synth)
```
Aspartate Transcaramoylase (second step)
-CP--> Carbamoyl Aspartate
```
119
What do "Sulfa" drugs do? Where is the key found in Purine synthesis?
Competitively inhibit a bact. enzyme incorporating PABA into Folate----in Pur, incorporated into PRA in lengthy step
Humans get folate vitamin in diet
BACTERIA
120
In Purine Catabolism, what is one of the second steps in the path, what is the enzyme? and What can be caused by an excess of it? but mainly a defeciency?
What is the main enzyme used in the end? What can it cause? and What drug is used to inhibit it?
Adenosine-->Inosine using Adenosine Deaminase
- -excess= Hemolytic Anemia
- -Def= SCID-----bubble boys
Xanthine Oxidase: HX-->X-->Uric acid
GOUT----inhibited by Allopurinol (Zyloprim)
121
What are important end products of Pyrimidine Catabolism?
Malonyl CoA
Succinyl Coa
Methylmalonyl CoA
122
What is the important enzyme in the Nuc Salvage Pathways? Leading to what complications?
HGPRT-hypoxanthine guanine phosphoribosyl transferase
Lesch Nyhan syndrome
Kelley-Seegmiller syndrome
123
What is the purpose of the drug Acyclovir?
Antiviral
Base that resembles Guanine...inserts into viral sequence
-lacks a 3' OH group--so DNA replication is terminated
Helps to heal sores related to chicken pox, shingles , and HPV
