First Aid: Biochemistry Flashcards
1
Q
Which two amino acids are histones rich in?
A
Lysine and Arginine
2
Q
Which histone is not on the histone core?
A
H1
3
Q
What are the two types of chromatin? Which one is more accessible for transcription?
A
Euchromatin is more accesible than Heterochromatin.
4
Q
What does DNA Methylation do?
A
Silence the DNA. Particularly in CpG islands.
5
Q
Which nucleotide(s) is/are methylated when DNA is silenced?
A
Cytosine and Adenine
6
Q
What is the difference between histone acetylation and methylation?
A
Methylation often silences DNA. Acetylation always Activates it.
7
Q
What are the two types of nucleotides? Name all the nucleotides in each type.
A
C, U & T are Pyrimidines. (CUT the Py) A and G are Purines. (Pure As Gold)
8
Q
What is the difference between nucleotides and nucleosides?
A
Nucleotides are phosphorylated and that makes them active.
9
Q
Which three drugs inhibit Dihydrofolate Reductase? What pathway is inhibited?
A
Methotrexate, Trimethoprim and Pyrimethamine. They inhibit dTMP (deoxythymidine monophosphate) synthesis.
10
Q
Which drug inhibits the synthesis of dTMP from dUMP?
A
5-fluorouracil (5-FU)
11
Q
Which drug inhibits ribonucleotide reductase?
A
Hydroxyurea. This is part of the pyrimidine synthesis pathway and that’s why it is given in myeloproliferative diseases and psoriasis.
12
Q
Which disease is caused by Adenosine Deaminase Deficiency?
A
Build-up of ATP and dATP prevents DNA synthesis and decreases lymphocyte proliferation. Autosomal Recessive SCID.
13
Q
What are the symptoms of Lesch-Nyhan Syndrome?
A
HGPRT: Hyperuricemia, Gout, Pissed Off (aggression, self-mutilation), Retardation, dysTonia. HGPRT enzyme deficiency. X-Linked Recessive.
14
Q
Which enzyme is deficient in Lesch-Nyhan syndrome?
A
HGPRT: Used in the recycling of degraded nucleotides.
15
Q
What is the treatment for Lesch-Nyhan syndrome?
A
Allopurinol or Febuxostat. To decrease hyperuricemia.
16
Q
What do you call a mutation that creates an early stop codon?
A
Nonsense
17
Q
In which disease is nucleotide excision repair damaged?
A
Xeroderma Pigmentosum
18
Q
In which disease is mismatch repair defective?
A
Hereditary Nonpolyposis Colorectal Cancer (HNPCC)
19
Q
Ataxia Talangiectasia is caused by a defect in DNA repair. Which type of damage cannot be fixed in this disease?
A
Double stranded breaks.
20
Q
What are the stop codons?
A
UGA, UAA, UAG
21
Q
Which type of RNA do each of the three RNA polymerases make?
A
Pol I: rRNA Pol II: mRNA Pol III: tRNA
22
Q
What does alpha-amantin inhibit?
A
RNA Polymerase II
23
Q
What is the name of the enzyme that splices mRNA?
A
snRNP which is made of RNA
24
Q
Which disease is caused by abnormal RNA splicing?
A
beta-thalassemia
25
Which enzyme is most responsible for the correct matching of codons to amino acids?
Aminoacyl-tRNA Synthetase. (Uses ATP)
26
What do initiation factors do?
Assemble ribosomal subunits with initiator tRNA and mRNA. Uses GTP.
27
What are the three sites of a ribosome?
A - Accomodates incoming
P - growing Peptide
E - Empty tRNA
28
What are the phases of mitosis?
Prophase, Metaphase, Anaphase & Telophase
29
What two tumor suppressor genes prevent the G1 to S phase transisiton?
p53 & Rb
30
With regards to cell cycle, what are the three cell types?
Permanent (G0)
Stable (G0 but can go to S)
Labile (Keeps cycling)
31
Describe the pathophysiology of I-Cell disease.
Lysosomal storage disease in which glycoproteins are not phosphorylated. Lysomal proteins are accidentally excreted instead. Inherited. Fatal.
32
What is the function of Signal Recognition Peptide (SRP)?
To recognize the C terminal patterns and deliver translation complexes to the Rough ER.
33
What type of transport are the two COP proteins responsible for?
COP I - Retrograde Golgi Transport
COP II - Anterograde Golgi Transport
34
What does Clathrin do?
tran-Golgi transport from the Golgi to vesicular organelles or the cell membrane.
35
The peroxisome is involved in the catabolism of which molecules?
Very long chain fatty acids, branched chain fatty acids, amino acids
36
What are the drugs that act on microtubules? (There is a pmemonic)
Mebendazole (anti-helmithic), Griseofulvin (anti-fungal), Colchcine (anti-gout), Vincristine/Vinblastine (anti-cancer)
Paclitaxel (anti-cancer)
Microtubules Get Constructed Very Poorly
37
Name the two molecules involved in microtubular transport and their direction.
Dyenin (+ to -)
Kinesin (- to +)
38
What are some of the complications of Kartagener Syndrome?
It is primary ciliary dyskinesia. Can result in male or female infertility, ectopic pregnancies, bronchiectasis, recurrent sinusitis, and situs inversus.
39
Which types of cell stain with GFAP?
Glial cells of the CNS.
40
Which type of cells stain with cytokeratin?
Epithelial cells.
41
Which drug directly inhibits the Na+/K+ ATPase Pump?
Digoxin (inhibits the whole protein)
42
What are the types of collagen and where are they located?
Be Like So Totally Cool Read Books
Type I - Bone, Liamanets, Skin, Tendons
Type II - Cartilage
Type III - Reticulin (and granulation tissue)
Type IV - Basement membrane
43
Why is vitamin C essential for collagen synthesis?
It is necessary for the hydroxylation of collagen in the RER
44
Describe the pathogenesis of Osteogenesis Imperfecta?
Defective glycosilation of colagen alpha chains in the RER. Mostly type I collagen.
45
What are some of the signs and symptoms of Osteogenesis Imperfecta?
Multiple fractures, blue sclerae, hearing loss, dental imperfections.
46
What is the treatment for osteogenesis imperfecta? (Similar to other bone conditions.)
Pamidronate: Pyrophosphate analogs that inhibit bone resorption.
47
Describe the pathophysiology of Ehlers-Danlos.
Problems with extracellular cross-linking of tropocollagen units. Different types of collagen cause different types of the disease.
48
What are some of the sign and symptoms of Ehlers-Danlos?
Hyperextensible skin, tendency to bleed or bruise, hypermobile joints.
49
What are some of the sign and symptoms of Menke's disease?
Kinky or Steel-wool-like hair, growth retardation, hypotonia. Similar pathophysiology to Ehlers-Danlos but due to impaired Cu absorption.
50
In genetics, what is variable expressivity?
Variables phenotypes for the same genotype.
51
In genetics, what is pleitropy?
Multiples genes contribute to one phenotype.
52
What is loss of heterozygosity?
When a heterozygous cell deletes or silences one copy of a gene turning it essentially homogenous. (ie. loss of tumor supressor genes.)
53
What is a dominant negative mutation?
The mutated gene inhibits the wild-type gene. (ie. competitive inhibition)
54
In genetics, what is locus heterogeneity?
Mutations in different lociproduce a similar phenotype.
55
In genetics, what is allelic heterogeneity?
Different mutations in the same loci that produce the same phenotype.
56
In genetics, what is heteroplasmy?
Heterozygosity within the mitochondria.
57
What are the symptoms of Prader-Willi Syndrome and what genetic abnormality is it caused by?
Hyperphagia, obesity, intelectual disability, hypogonadism, and hypotonia. Maternal disomy of chromosome 15.
58
What are the symptoms of Angelman syndrome and what genetic abnormality is it caused by?
Inappropiate laughter, seizures, ataxia, and intellectual disability. Paternal disomy.
59
Which gene is defective in Cystic Fibrosis? How does it affect the mucus and sweat gland secretions?
CFTR gets a Phe deletion, Cl- cannot be secreted in the mucosa and those water secretion is reduced resulting in thick mucus. In sweat glands Cl- cannot be reabsorbed resulting in salty sweat.
60
What are some of the lab findings of Cystic Fibrosis?
Contraction alkalosis and hypokalemia from renal K+ and H+ wasting. Similar to being on loop diuretics.
61
What is the pattern seen in the CXR of a patient with Cystic Fibrosis?
Renticulonodular from the chronic bronchitis and bronchiectasis.
62
What are some of the complications of Cystic Fibrosis beyond chronic lung infections?
Pancreatic insufficiency, malabsorption (esp. fat soluble vitamins), steatorrhea, nasal polyps, meconium ileus, absent vas deferens.
63
Which two drugs are given to loosen the mucus of cystic fibrosis patients?
N-acetylcysteine (to clease disulfide bonds in mucus), Dornase alfa (DNAase to clear leukocytic debris)
64
Which type of inheritance do most muscular dystrophies follow?
X-Link Recessive
65
Which gene is mutated in Duchenne and Becke's Muscular Dystrophy?
Dystrophin. Whose function it is to anchor the cytoskeleton to the transmembrane proteins in cardiac and skeletal muscle.
66
Which of the muscular dystrophies is more severe and has earlier onset?
Duchenne is more severe than Becker.
67
What are some of the signs and symptoms of Muscular Dytrophy?
Weakness of PROXIMAL muscles, pseudohypertrophy of calf muscles (fatty replacement), Gower maneuver (walking up hands to get up), dilated cardiomyopathy.
68
What are the signs and symptoms of Myotonic Muscular Dystrophy Type 1?
Myotonia, muscle wasting, frontal balding, cataracs, testicular atrophy, and arrhythmia.
69
What are the signs and symptoms of Fragile X Syndrome?
Pepubertal macroorchidism, long face with a large jaw, large everted ears, autism, mitral valve prolapse. (Fragile X = eXtra large testes, jaws and ears)
70
Besides flat facies and epicanthal folds what other signs and symptoms are present in Down Syndrome? (Trisomy 21)
Single palmar crease, gap between 1st and 2nd toes, duodenal atresia, Hirschprung, congenital heart deffects, increased risk of ALL, AML and AD.
71
What are the abnormal finding in the quad screen that would suggest Down Syndrome?
Decfreased AFP and Estriol, Increased b-hCG and inihibin A.
72
What are it's prominent features in Edwards Syndrome?
Rocker bottom feet, micrognathia, **low set ears, clenched hands**, prominent occiput, congenital heart disease.
73
What is the genetic abnormality seen in Edwards Syndrome? What are the abnormal quad screen findings in the quad screen?
Trisomy 18 (Election age). Decreased AFP, b-hCG, and estriol. Normal or decreased inhibin A.
74
What is the genetic abnormality seen in Patau Syndrome?
Trisomy 13. (Puberty age)
75
What are the prominent physical features of Patau Syndrome?
Rocker bottom feet, micropthalmia, microcephaly, **claft liP and Palate, holoProsencephaly, Polydactyly**, congenital hear disease.
76
What is Robertsonian Translocation?
When the centromeres of acrocentric chromosomes (chromosomes with one really short arm) fuse and casue nondisjunction. Most likely chromosomes are 13, 14, 15, 18, 21 and 22.
77
What is the genetic abnormality in Cri-du-chat syndrome?
Short arm of Chromosome 5 deletion (5q-)
78
What are the sign and symptoms of Cri-du-chat Syndrome?
**High pitched crying** (cry of the cat), epicanthal folds, Ventral Septal Deffect.
79
What is the genetic abnormality in Williams Syndrome?
Deletion of the long arm of chromosome 7. (7q-)
80
What are the signs and symptoms of Williams Syndrome?
Elfin facies, intellectual disability, hypercalcemia, normal verbal skills, extreme friendliness with stranger, CV problems.
81
What genetic abnormality causes both DiGeorge Syndrome and Velocardiofacial Syndrome?
Microdeletion in the long arm of chromosome 22. (22q11)
82
What are the signs and symptoms of the 22q1 deletion syndromes?
Deformities involve the 3rd and 4th branchial pouches. CATCH-22
Cleft palate, Abnormal facies, Thymic aplasia, Cardiac defects, Hypocalcemia (parathyroid aplasia)
DiGeorge and Velocardiofacial Syndrome
83
What are the signs and symptoms of DiGeorge Syndrome?
Thymic, parathyroid, and cardiac defects.
84
What are the signs and symptoms of Velocardiofacial Syndrome?
Palate, facial and cardiac defects.
85
Which vitamins are fat soluble?
ADEK
86
What si the name of Vitamin A and where is it found? What conditions does it treat?
Retinol. Liver and leafy vegetables. It serves as an antioxidant and it is essential for the differetiation of epithelial cells into specialized tissue. It is used to treat acne and skin wrinkles.
87
What are the symptoms of vitamin A deficiency?
Night blindness, dry & scaly skin, alopecia, corneal degeneration.
88
What are the symptoms of Vitamin A excess?
Arthralgias, skin changes, alopecia, cerebellar edema, pseudotumor cerebri, osteoporosis, hapatic abnormalities, teratogen.
89
Which three enzymes require thiamine (Vitamin B1) to function?
Think ATP: alpha-ketoglutarate, transketolase, pyruvate dehydrogenase
90
Which three conditions are caused by thiamine (Vitamin B1) defficiency? What is the underlaying biochemical problem?
Wernicke-Korsakoff Syndrome, Dry beriberi, Wet beriberi. Thiamine pyrophosphate is a cofactor for three enzymes heavily involved in glocose metabolism. The CNS is affected first. Memory loss may be permanent.
91
What are the symptoms of dry beriberi?
Polyneuritis and symmetrical muscle wasting.
92
What are the symptoms of wet beriberi?
high-output cardiac failure (dilated cardiomyopathy), edema
93
What are the symptoms of Wernicke-Korsakoff syndrome?
**Traid:** confusion, opthalmophlegia, ataxia
**Extra:** Confabulation, personality change, memory loss. Damage to medial dorsal nucleus of the thalamus and mammilary bodies.
94
What is the name of Vitamin B2? Which two cofactors are derived from it?
Riboflavin is made into cofactors FAD & FMN.
95
What are the two main signs of vitamin B2 deficiency?
Cheilosis (inflammation of lips, scaling and fissures at the corner of the mouth) and Corneal vascularization (The 2 Cs of B2)
96
What is the name of vitamin B3? Which cofactors is it part of?
Niacin, NAD+ and NADP+
97
What can conditions can arise from a Vitamin B3 deficiency? How about excess?
Deficiency causes Glossitis or Pellagra (Severe). Excess cuases facial flushing, hyperglycemia, hyperuricemia.
98
What are the four causes of pellagra?
Hartup disease (low tryptophan absorption)
Malignant Carcinoid Syndrome (high tryptophan absorption)
Isoniazid (low vitamin B6)
Niacin deficiency (low vitamin B3)
99
What is the classic traid seen in pellagra?
Diarrhea, Dementia, Dermitisi (Casal necklace or hyperpigmentation in sun exposed areas)
The 3 Ds of B3.
100
What is the name of Vitamin B5 and of which compound is it a component?
Pentathenate is a component of Coenzyme A.
101
What is the name of vitamin B6 and which type of reaction is a cofactor for?
Pyridoxine is a cofactor for transamination and decarboxylation reaction. It is involved in the synthesis of a lot of neurotranmitters. (5HT, Epi, NE, D, GABA)
102
What are the signs and symptoms of vitamin B6 deficiency?
Peripheral neuropathy, convulsions, hyperirritability.
103
What is the name of vitamin B7 and which type of reaction is it a cofactor for?
Biotin is a cofactor for carboxylation enzymes. (ie. Pyruvate, Acetyl-CoA and Propionyl-CoA carboxylases)
104
What are the signs and symptoms of vitamin B7 deficiency? What is that one strange way of aquiring a B7 deficiency?
Dermatitis, alopecia, enteritis. Can be caused by excessive ingestion of raw egg whites, which contain avid. Avid binds biotin.
105
What is the name of vitamin B9?
Folate
106
Asside from megaloblastic anemia which other signs and symptoms can be seen in vitamin B9 deficiency?
Hypersegmented PMC, glossitis, increased homocysteine. Normal neurologic findings and methylmalonic acid.
107
What is the name of vitamin B12?
Cobalamin
108
Aside from megaloblastic anemia what are the other signs of vitamin B12 deficiency?
Hypersegmented PMC, paresthesias, subacute combined degeneration of spinal tracts. Increased homocysteine AND methylmalonic acid.
109
What are the causes of vitamin B12 deficiency?
Intake (vegan EtOH)
Malabsorption (sprue, enteretis, Diphyllobothrium latum, Chrohn disease)
Intrinsic factor (pernocious anemia, gastric bypass)
110
What is the name of vitamin C and what are some of it's functions?
Ascorbic acid is an antioxidant, fascilitates Fe+ absorption, hydroxylation of collagen, hydroxylation of D to make NE.
111
What are the signs and symptoms of vitamin C deficiency?
Scurvy: **Swollen gums, bruising**, hemarthrosis, anemia, poor wound healing, **perifollicular** and subperiosteal hemorrhages, **corkscrew hair**.
112
What are the two functions of Vitamin D?
Intestinal absorption of Ca++ & mineralization of bone
113
What are the signs and symptoms of vitamin D deficiency?
Rickets in children = Bone pain and deformity (leg bowing)
Osteomalacia in adults = bone pain and muscle weakness
114
What are the signs and symptoms of vitamin D excess?
Hypercalcemia/uria, loss of apetite, stupor. Seen in sarcoidosis.
115
What is the function of vitamin E?
It's an antioxidant that protects Erythrocytes from free radical damage.
116
What are the signs and symptoms of vitamin E deficiency?
Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelenation. (Similar to B12)
117
Vitamin K is an important cofactor for the activation of which proteins?
Factors 10, 9, 7, 2.
Protein C and Protein S.
118
What are the symptoms of zinc deficiency?
Delayed wound healing, hypogonadism, decreased adult hair, dysgeusia, anosmia, **acrodermatitis enteroathica (can also be due to congenital zinc absorption deficiency)**.
119
What are the two proteins involved in EtOH metabolism? Where in the cell are they located? What is the final product?
Alcohol Dehydrogenase in the cytoplasm. Acetaldehyde dehydrogenase in the mitochondria. Ends with acetate.
120
What is the rate limiting reagent in alcohol metabolism?
Both alcohol and acetaldehyde dehydrogenase consume one NAD+. And thus NADH builds up after a binge.
121
What are some symptoms that can be seen in an increased NADH/NAD+ ration?
Lactic acidosis, ketoacidosis, fasting hypoglycemia, steatosis. All because they are metabolism that require less NAD+ compared to the TCA cycle.
122
What is the mechanism and clinical use of Fomepizole?
Inhibits alcohol dehydrogenase. Used for ethylene glycol poisoning.
123
What is the mechanism and clinical use of Disulfiram?
Inhibits acetaldehyde dehydrogenase and causes a build up of acetaldehyde. Used for alcohol dependence.
124
What are the two types of malnutrion and how is their etiology different?
Kwashiorkor is a result of protein deficiency. Marasmus is a result of total caloric insuficiency.
125
What are the signs and symptoms of Kwashiorkor malnutrition?
MEALS: Malnutrition, Edema, Anemia, Liver is fatty, Skin lesions.
Due to deficienct apolipoprotein synthesis. Round belly.
126
What is the natural course of Marasmus malnutrition?
Muscle and tissue wasting. Loss of subcutaneous fat. Potentially edema.
127
Which three metabolic processes take blace in both the mitochondria and cytoplasm?
Heme synthesis, urea cycle, gluconeogenesis. (HUGs take two.)
128
What is the rate determining enzyme in Glycolysis?
Phosphofructokinase-1 (PFK-1)
129
What is rate determining enzyme in Gluconeogenesis?
Fructose-1,6-bisphosphatse. Which reverses the actions of PFK-1, the rate-determining enzyme in glycolysis.
130
What is the rate determining enzyme in the TCA Cycle?
Isocitrate Dehydrogenase
131
What is the rate determining enzyme in glycogenesis?
Glycogen Synthase. That's easy.
132
What is the rate determining enzyme in Glycogenolysis?
Glycogen phophorylase.
133
What is the rate determining enzyme in the HMP Shunt?
Glucose-6-Phophate Dehydrogenase (G6PD)
134
What is the rate determining enzyme in De Novo Pyrimidine Synthesis?
Carbamoyl Phosphate Synthase II
135
What is the rate determine enzyme in De Novo Purine Synthesis?
Glutamine-phosphoibosylpyrophosphate (PRPP) aminotransferase
136
What is the rate determining enzyme in the Urea Cycle?
Carbamoyl Phosphate Synthase I. Creates a Carbomyl Phosphate using using an HCO3, a P group from ATP and the NH3 group from an amino acid.
137
What is the rate determining enzyme in fatty acid synthesis?
Acetyl-CoA Carboxylase (ACC)
138
What is the rate determining enzyme in fatty acid oxidation?
Carnite Acyltransferase I. Which is necessary for transport of the Acyl-CoA (fatty acid + CoA) into the mitochondria.
139
What is the rate determining enzyme in ketogenesis?
HMG-CoA synthase.
140
What is rate determining enzyme in cholesterol synthesis?
HMG-CoA reductase.
141
How many ATP molecules can be produced from glucose?
32
142
What are some of the differences between hexokinase and Glucokinase? They both make G6P from glucose.
Glucokinase is in the liver and beta-cells of the pancreas, it's insulin independent and it is has a higher KM and VMax. (More active during starvation.)
Hexokinase is in the other tisues, it's insulin dependent and it is has a lower KM and VMax. (More active in hypoglycemia.)
143
What are the findings in Pyruvate Dehydrogenase Complex deficiency? Try to name 3.
Neurologic defects, lactic acidosis and high serum alanine starting at infancy. Because Pyruvate gets shunted to either Lactate or alanine.
144
What is the treatment for pyruvate dehydrogenase complex deficiency?
Highly ketogenenic diet. Lysine and Leucine are the only purely ketogenic amino acids. (After K comes LL)
145
What are the four possible products of pyruvate metabolism? Try to think about why each of them is important.
Alanine (amino group carrier), Oxaloacetate (forms the basis of the TCA cycle), Acetyl-CoA (enters the TCA cycle), Lactate (for anaerobic glycolysis)
146
What does 2,4-Dinitrophenol do?
It allows protons to escape the mitochondrial interspace and thus causes heat and decreased ATP production.
147
What is the point of entry in the TCA cycle of for the metabolites of odd chain fatty acids?
Propionyl CoA can be made into Succinyl-CoA.
148
What is the purpose of the HMP shunt?
To provide NADPH for reductive reactions and Ribose for nucleoside synthesis. The HMP shunt starts at Glucose-6-Phosphate (G6P)
149
Describe the pathofisiology of Chronic Granulomatous Disease? (Hint: it begins with a protein deficiency.)
Without NADPH phagocytes cannot make reactive oxigen species. Therefore they enter "frustrated phagocytosis" and create a granuloma. They are at increased risk of infection by Catalase+ microbes.
150
How do G6PD, Glutathione reductase and Glutathione peroxidase work together?
G6PD produces NADPH, GR uses up NADPH to reduce Glutathione, GP uses up a glutathione to neutrolize a peroxide.
151
What are the two diseases of fructose metabolism? Which one is more severe?
**Essential fructosuria** is due to a Fructokinase deficiency and it is benign as fructose is not trapped in cells. Fructose intolerance is more serious as F1P accumulates.
152
What are the signs and symptoms of Galactokinase deficiency?
Galactitol and Galactose accumulates in the blood urine. Relatively benign. Autosomal recessive. May cause infantile cataracs and presents as failure to track objects or smile.
153
What are the signs and symptoms of Galactose-1-phosphate Uridyltransferase deficiency?
Accumulation of galactitol and other damaging metabolites causes failure to thrive, jaundice, hepatomegaly, infantile cataracs, intellectual disability. EXCLUDE Galactose and Lactose from diet.
154
Why does excess Galactose cause accumulation of Galactitol?
Aldose Reductase converse Galactose to its alcohol form. Galactitol. This is the same enzyme that converts Glucose to Sorbitol.
155
What is the pathophysiology of hyperglycemic damage caused through sorbitol?
Glucose is converted to sorbitol and trapped inside the cell. In cells without Sorbitol Dehydrogenase (ie. Schwann, Retina & Kidney) sorbitol build up causes osmotic damage.
156
What is an alpha-ketoacid?
An amino acid without the amino group. (ie. alpha-ketoglutarate)
157
Where does the Urea Cycle mostly take place?
Liver
158
Describe the pathophysiology of the complications caused by hyperammonemia?
alpha-ketoglutarate is used up because it is all used up to make Glutamate, an ammonia carrier. Since alpha-ketogluterate is part of the TCA cycle there is a decrease in the ATP production.
159
What are the signs and symptoms of hyperammonimia (ammonia intoxication)?
Tremor, Slurred speech, somnolence, vomiting, cerebral edema, blurry vision.
160
What is the treatment for hyperammonemia in addition to the reduction of protein in the diet?
Benzoate or Phenylbutyrate can bind amonia. Lactulose acidifies the GI and reduces ammonia absorption.
161
What is the inheritance pattern of Ornithine Transcarbamylase Defficiency?
X-Linked Recessive.
162
What are the signs and symptoms of OTC deficiency?
Carbamoyl goes down the pyrimidine synthesis pathway instead and causes excess orotic acid. Low BUN, low Urea in the urine and hyperammonemia (including symptoms). Eveident neonatally.
163
Why are phenylketones found in the urine in phenylketonuria?
A defficiency in the Phenylanine Hydroxylase (Phenylamine -\> Tyrosine) causes a build up of phenylalanine which is ketogenic. Autosmal recessive.
164
What are the signs and symptoms of PKU?
Intellectual disability, growth retardation, seizures, fair skin, eczema, musty body odor (phenyl=aromatic)
165
What is the treatment for PKU?
Diet. Decreased phenylalanine and increased tyrosine, which is now essential.
166
What is the complication and treatment for cystinuria?
Cysteine, Ornithine, Lysine and Arginine cannot be reabsorbed in the PCT so hexagonal crystals form. Tx: Potassium Citrate or Acetazolamide to alkalinize the urine.
167
Described the pathophysiology of Maple Syrup Urine Disease?
Blocke degradation of branched amino acids; Isoleucine, Leucine & Valine. (I Love Vermont Maple Syrup.)
168
What are the signs and symptoms of Maple Syrup Urine Disease?
CNS defects from increased alpha-ketoacids. Urine smells like maple syrup.
169
What is the treatment of Maple Syrup Urine Disease?
Diet. Low on Isoleucine, Leucine and Valine with Thiamine supplemantation, for alpha-ketoacid dehydrogenase.
170
What type of receptor is the insulin receptor?
Tyrosine Kinase Dimer
171
What type of receptor is the Glucago Receptor?
Gs - G Protein Coupled Receptor
172
Which three hormones regulate glucose metabolism?
Insulin, Glucagon and **Epinephrine** (similar effects to Glucagon).
173
What is the differences between branching and linkage bonds in glycogen?
Branches have alpha 1,6 and linkages are alpha 1,4.
174
Why is debranching enzyme useful?
Because glycogen phsphorylase cannot performs glygenolysis on branches shorter than 4 sugars.
175
What are the four glycogen storage diseases?
Von Gierke = Type I
Pompe = Type II
Cori = Type III
McArdle = Type IV
(Very Poor Carb Metabolism)
176
Describe the pathophysiology of Von Gierke disease.
Deficiency in Glucose-6-Phosphatase. Golucose gets trabbed in hepatocytes and there is a severe fasting hypoglycemia. Increased blood lactate.
177
Describe the pathophysiology of Pompe disease.
Lysosomal glycogenolysis is deficient. (alpha-1,4 glucosidase). Leads to problems with the cardiomyopathy, liver and muscle. Early death.
178
Describe the pathophysiology of Cori disease.
Lack of debranching enzyme (alpha-1,6-glucosidase) so glycogen builds up in hepatocytes. Less severe than Von Gierke's.
179
Describe the pathophysiology of McArdle disease.
Defficiency in skeletal mucle glycogen phosphorylase. Painful muscle cramps and myoglobinuria and electrolite abnormalities leading to arrythmia.
180
What is the biochemical consequence of a carnite deficiency?
Long chain fatty acid degradation is inhibited because Carnite is a necessary co-transpoter for Acyl-CoA into the mitochondria.
181
What is the starting product in fatty acid synthesis? Where is it found?
Citrate is found in the mitochondria as it is an important step in the TCA cycle.
182
What does Malonyl-CoA inhibit?
Co-tansport of carnite and Acyl-CoA into the mitochondria and thus it inhibits fatty acid degradation.
183
Why is ketone body production increased in starvation, DKA and alcoholism?
In DKA and starvation oxaloacetate is shunted into gluconeogenesis. In alcoholism excess NADH shunts oxaloacetate into malate. Both cause a build up of acetyl-CoA which shunts metabolites into ketone body projection.
184
Which ketone body is picked up in urine testing?
Acetoacetate is. beta-Hydroxybutyrate is not.
185
Oraganize protein, fat, carbohydrates and alcohol from least to energy dense?
Protein = Carbohydrates (4kcal/g) \< Alcohol (7kcal/g) \< Fat (9kcal/g)
186
How much time before glycogen storage is depleted in fasting/starvation?
Within 1 day.
187
Which hormone (not drug) induces HMG-CoA reductase?
Insulin
188
What is the function of Lipoprotein Lipase?
On gut endothelial cells it frees fatty acids from chylomicrons. On other endothelial cells it frees fatty acids from VLDL. VLDLs become IDL.
189
What is the function of hepatic lipase?
In the liver it degrades IDL into LDL.
190
What is the function of Lecithin-cholesterol acyltransferase LCAT?
Esterification of cholesterol
191
What does the LDL Receptor bind?
ApoB-100
192
Which apolipoprotein mediates chylomicron remnant uptake?
E
193
Which apolipo protein activates LCAT?
A-I
194
What is the pathophysiology of type I familial dyslipidemia?
LPL or ApoCII deficienciency whych leads to a hyperchylomicronemia.
195
What is the pathophysiology of type IIa familial dyslipidemia?
Defective LDL receptors. Heterozygotes are partially affected. Leads to high LDL.
196
What is the pathophysiology of type IV familial dyslipidemia?
Autosomal dominant hepatic over-production of VLDL. Leads to pancreatitis.
197
What is the inheritance pattern of Fabry disease and what are the symptoms?
It is one of the two XR lysosomal storage diseases. Causes peripheral neuropathy and angiokeratomas from Ceramide Trihexoside build up.
198
What is the inheritance pattern of Gaucher's disease and what are the symptoms?
Recessive. Hepatosplenomegaly, aseptic femur necrosis, pancytopenia, Gaucher's macrophages (which look like tissue paper from build up of Glucocerebroside)
199
What is the inheritance pattern of Neimann-Pick disease and what are the symptoms?
Recessive. Neurodegenaration, hepatosplenomegaly, and cherry red spots in the macula. Due to sphingomyelin build up. (No man picks his nose with his phinger)
200
What is the inheritance pattern of Tay-Sachs disease and what are the symptoms?
Recessive. Progressive neurodegenation with cherry red spots on the macula but no hepatosplenomegaly. Build up of GM2 ganglioside.
201
What is the inheritance pattern of Krabbe disease and what are the symptoms?
Recessive. Peripheral neuropathy, developmental delay, optic atrophy, globoid cells. Build up of Galactocerebroside.
202
What is the inheritance pattern of Metachromatic Leukodystrophy and what are the symptoms?
Recessive. Central and peripheral demyelination from a Cerebroside Sulfate build up.
203
What is the inheritance pattern of Hurler Syndrome and what are the symptoms?
Recessive. Developmental delay, gargoylism, airway obstruction, corneal clouding and hepatosplenomegaly. From heparan sulfate and dermatan sulfate build up. (Alpha l rudonidase)
204
What is the inheritance pattern of Hunter Syndrome and what are the symptoms?
Mild hurler syndrome. Aggressive behavior and no corneal clouding. Hunters see clearly (no corneal clouding) and aggressively aim for the X (X-linked recessive). From a build up of heparan sulfate and dermatan sulfate.
205
What is the conezyme of Phenylalanine Hydroxylase?
Tetrahydrobiopterin or BH4. Lack of BH4 can mimic PKU.
206
What are the two mutated genes in Neurofibromatosis?
NF1 on Chormosome 17 for type 1. NF2 on Chromosome 22 for type 2.
207
What are the signs and symptoms of neurofibromatosis?
Cafe-au-lait spots (I), cutaneous neurofibromas, schwannomas, meningioma, ependymoma.
208
What is the difference between promoters & enhancers?
Promoters are required (ie. TATA at -25bp or CAAT at -70bp) enhancers can change expression and can be located anywhere.
