Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
115 Cards in this Set
- Front
- Back
|
Mechanism of alcohol induces hypoglycemia
|
NADH increase prevents gluconeogenesis by shunting pyruvate and oxaloacetate to lactate and malate
|
|
|
51 yo man wih black spots in sclera and black urine upon standing
|
alkaptonuria
|
|
|
woman with cramps and dark urine after exercise
|
McArdle's dz
|
|
|
Alcoholic with rash, diarrhea, and AMS
|
Pellagra (vit B3)
|
|
|
What are the primary deficiencies in B-complex deficiencies
|
dermatitis, glossitis, diarrhea
|
|
|
What are the sxs of Vit A deficiency
|
night blindness and dry skin
|
|
|
What are the sxs of Vit B1 (thiamine deficiency
|
Beriberi -- dry --polyneuritis, musc wasting; wet--high output CF (dil cardiomyopathy)
Wernicke-Korsakoff |
|
|
What is the function of Vit A
|
Visual pigments -- retinal
|
|
|
What is the function of Thiamine B1
|
cofactor for oxidative decarboxylation of a-keto acids (pyruvate, a-ketoglutarate)
cofactor fo transketolase in HMP shunt |
|
|
What are the sxs of Vit B2 deficiency (riboflavin)
|
angular stomatitis, cheilosis, corneal vascularization
|
|
|
What is the function of B2 (riboflavin
|
cofactro in oxidation and reduction --FADH2 and FAD/FMN --> 2ATP
|
|
|
What is the B3 deficiency called
|
Pellagra
|
|
|
What are the primary sxs of pellagra
|
Diarrhea, Dermatitis, and Dementia and beefy glossitis
|
|
|
What are some causes of pellagra
|
Hartnup dz (decrease tryptophan absorption)
malignant carcinoid syndrome (increased tryptophan metab) Isoniazid ( decrease vitamin B6) |
|
|
What is the function of B3 (niacin)
|
Constituent of NAD+ and NADP+; used in redox rxns; derived from tryptophan using B6.
|
|
|
What are the sxs of B5 (pantothenate) deficiency
|
Dermatitis, enteritis, alopecia, adrenal insufficiency 2/2 insufficiency of fatty acid synthase
|
|
|
What is the function of B5 (pantothenate)
|
constituent of CoA (cofactor for acyl transfers) and component in fatty acid synthase
|
|
|
What are the sxs of B6 (pyridoxine) deficiency
|
convulsion, hyperirritability --> deficiency due to INH and oral contraceptives
|
|
|
What is the fx of B6 (pyridoxine)
|
converted to pyridoxal phosphate-- cofactor used in transamination (ALT/AST), decarboxylation, and heme synthesis
|
|
|
What are the sxs of B12 (cobalamin) deficiency
|
Macrocytic, megaloblastic anemia, neurologic sxs (optic neuropathy, SCD, paresthesia), glossitis
|
|
|
What is the function of B12 (cobalamin)
|
cofactor in homocysteine methylation --> xfer CH3 --> Methionine + THF
and methylmalonyl-CoA handling stored in liver, large reserve pool synthesized by micro-organisms |
|
|
What are the causes of B12 deficiency
|
found only in animal products;
caused by malabsorption --> sprue, diphyllobothrium latum, lack of intrinsic factor (pernicious anemia), absence of terminal ileum (crohns) |
|
|
what test is used to detect B12 deficiency
|
Schilling test --radioactive B12 given orally, and elimination in urine measured; if urine conc. is low, either malabsorption or IF deficiency. Give IF and B12 again, to rule out absorption
|
|
|
What causes myelin abnlities seen in B12 deficiency
|
decreased methionine or increase methylmalonic acid
|
|
|
What are the sxs of folic acid deficiency
|
macrocytic, megaloblastic anemia (no neuro sxs)
|
|
|
What is the function of folic acid
|
coenzyme (Tetrahydrofolate--THF) for 1-carbon transfers, important for synthesis of nitrogenous bases in DNA and RNA
|
|
|
What causes folic acid deficiency
|
lack of green vegetables -->
PABA is folic acid precursor in bacteria; sulfa drugs and dapsone --> PABA analogs |
|
|
What happens with folic acid deficiency in pregnancy
|
neural tube defects
|
|
|
What are the sxs of biotin deficiency
|
dermatitis, enteritis
|
|
|
what causes biotin deficiency
|
antibiotic use and ingestion of raw eggs
|
|
|
What is the function of biotin
|
cofactor for carboxylations
1.) pyr --> oxa 2.) AcetylCoA --> malonyl-CoA 3.) Prorionyl-CoA --> methylmalonylCoA |
|
|
What are the sxs of vit C (ascorbic acid) deficiency
|
Scury -- swollen gums, bruising, anemia, poor wound healing
|
|
|
What is the function of vit C
|
necessary for hydroyxlation of Proline and lysine in collagen synthesis
facilitates Fe absorption by keeping Fe in reduced state necessary as cofactor in DA --> NE |
|
|
What are the sxs fo VitD deficiency
|
Rickets in kids; osteomalacia in adults and hypocalcemic tetancy
|
|
|
What are the sxs of vit D excess
|
Hypercalcemia, loos of appetite, stupor --> seen in Sarcoidosis where Mphages convert vitD to active form
|
|
|
What type of vitD is found in milk
|
D2
|
|
|
What type of vitD is formed in skin
|
D3
|
|
|
What is the storage form of vitD
|
24,25-OH D3 or 25-OH D3
|
|
|
What are the sxs of Vit E deficiency
|
Increase fragility of RBC, neuro dysfx
|
|
|
what is the fx of Vit E
|
Antioxidant (protect erythrocytes from hemolysis)
|
|
|
What are the sxs of VitK
|
neonatal hemorrhage, increased PT and PTT with nl bleeding time
|
|
|
what factors are vit K dependent
|
II, VII, IX, X and protein C and S
|
|
|
What is the function of vit K
|
catalyzed gamma-carboxylation of glutamic acid residues on various clotting proteins; synthesized by intestinal flora;
|
|
|
what can cause vit K deficiency
|
prolonged use of broad spectrum antibiotics
|
|
|
What are the sxs of zinc deficiency
|
delayed wound healing, hypogonadism, decreased adult hair(axillar, facial, pubic)
|
|
|
What is the limiting reagent in ETOH metabolism
|
NAD+
|
|
|
What is the first setp of ETOH metabolism
|
Ethanol --> Acetaldehyde by ETOH dehydrogenase and NAD+ --> NADH
zero order kinetics |
|
|
What is the 2nd step of ETOH metab
|
Acetaldehyde --> Acetate by Acetaldehyde dehydrogenase and NAD+ --> NADH
|
|
|
What is the Disulfram rxn
|
Disulfram inhibits acetaldehyd dehydrogenase --> acetaldehyde accumulation --> hangover sxs
|
|
|
What is the mechanism of ETOH hypoglycemia
|
increased NADH/NAD+ ratio --> diversion of pyruvate to lactate and OAA to malate, --> inhib of gluconeogenesis --> hypoglycemia
and shunt to fatty acid synthesis (causes hepatic fatty change) |
|
|
What differentiates Kwashiokor from marasmus
|
Kwashiokor -- protein malnutrition --> skin lesion, edema, liver malfx (small child with swollen belly)
Marasmus-- energy malnutrition --> tissue and muscle wasting, no subq fat and variable edema |
|
|
what is heterochromatin
|
condensed, transcriptionally inactive DNA
|
|
|
which nucleotides are purines
what are pyrimadines |
A, G
CUT |
|
|
Which form three H-bonds
|
G and C
|
|
|
What AA forms Purines
|
Aspartate, CO2, Glycine, THF, Glutamine
|
|
|
What AA forms Pyrimidines
|
Aspartate and Carbamoyl Phosphate
|
|
|
Which has multiple origins of replication
|
Eukaryotes, AT-rich base pairs
|
|
|
Which have single origin of replication
|
Prokaryotes --> bidirectional DNA synth with Okazaki on lagging strand
|
|
|
What does DNA topoisomerase do
|
creates nick in helix to relieve supercoils
|
|
|
What does primase do
|
makes RNA primer on which DNA polyIII initiates replication
|
|
|
What does DNA poly III do
|
elongates chain (5'-->3' synthesis) and has 3'-->5' exonuclease activity
|
|
|
What does DNA poly I do
|
degrades RNA primer and fills with DNA; excises the 5'-->3' exonuclease
|
|
|
What does DNA ligase do
|
seal the strands
|
|
|
what disorder has damaged nucleotide excision repair
|
Xeroderma pigmentosa
|
|
|
what disorder has impaired mismatch repair
|
HNPCC
|
|
|
What direction are DNA and RNA synthesized
|
5'--> 3' (5' end has phosphate group)
|
|
|
RNAs -- which is most abundant, largest, aand smallest
|
rRNa, mRNA, and tRNA
|
|
|
What do RNA polymerase I, II, and III synthesized respectively
|
I -- rRNA
II -- mRNA III -- tRNA in the order of protein synthesis |
|
|
What are the Three stop codons
|
UGA, UAG, UAA
|
|
|
What AA is the coded for by the start codon
|
methionin (AUG or GUG)
formyl-methionine in prokaryotes |
|
|
What is the promotor segment
|
site of RNA poly and other transcription factors bind DNA upstream of the gene locus
Typically, AT rich wih TATA adn CAAT boxes |
|
|
What are the typical effects of promotor mutation
|
decrease in gene transcription
|
|
|
What is the Enhancer
|
segment of DNA that alters gene expression by binding transcription factors
|
|
|
What is an operator sequence
|
site where negative regulators (repressors) bind
|
|
|
Which are expressed -- introns or exons
|
Exons
|
|
|
What are the steps of RNA processing
|
Occurs in nucleus
1.) 5' end capping (7-methyl-G) 2.) PolyA tail -- 3' end 3.) Splicing of introns only processed RNA is transported out of the nucleus |
|
|
Which end of tRNA is the AA attached
|
3'
|
|
|
What enzyme charges tRNA
|
aminoacyl-tRNA synthase, consumes 1 ATP, has proofreading function for proper tRNA charging
|
|
|
What are the 3 steps of protein synthesis
|
initiation, elongation, and termination
|
|
|
what is Initiation in protein synth
|
initiation factors assemble 30S ribosomal subunit with the initiator tRNA
|
|
|
What are the roles of ATP and GTP in protein synthesis
|
ATP is hydrolyzed in tRNA charging
GTP is used for translocation of the ribosome |
|
|
What are the three sites of the ribosome and what is each function
|
A site -- incoming Aminoacyl tRNA
P site -- accommodates growing peptide E site-- hold Empty tRNA as it exits |
|
|
What are the 3 step of elongation in protein synthesis
|
1. Aminoacyl tRNA binds to A site
2. peptidyl transferase catalyzes peptide bond formation and transfers polypeptide to AA in A-site 3. Ribosome advances the nucleotides (3' direction) moving peptidyl RNA to Psite |
|
|
What takes place in termination of protein synthesis
|
release of protein and dissociation of ribosome
|
|
|
What are some post-translational modifications of proteins
|
Trimming -- removal of N- or C-terminal pro-peptides
Covalent alteration--phophorylatioin, glycosylatioin, hydroxylation Proteasomal degradation--ubiquitination of defective proteins |
|
|
What regulates transitions between cell cycle phases
|
cyclins
cdk tumor suppressors |
|
|
What are the stages of the cell cycle
|
Mitosis (pro, meta, ana, telo)
G1--Growth S- synthesis G2-- |
|
|
What phase and type of cells remain in the following:
Permanent Stable Labile |
Permanent: G0--neurons, skeletal, cardiac muscle, RBC
Stable: G1 from G0 when stim--> hepatocytes and lymphocytes Labile: G1 -- bone marrow, gut epithelium, skin, hair follicles |
|
|
What is the function of the RER
|
site of synthesis of secrete proteins and N-linked oligosaccharide addition
|
|
|
What types of cell are rich in RER
|
mucus-secreting cells -- Goblet cells;
plasma cell secreting Ab neurons-- Nissl bodies -- enzymes and peptide NTs |
|
|
What is the function of SER
|
site of steroid synthesis and detoxification of drugs and poisons
Liver cells and adrenal cortex cells rich in SER |
|
|
What are some functions of the Golgi system
|
1. Distribution of proteins and lipids
2. Modify n-oligosaccharides on asparagine 3. add O-oligosacc to serine and threonine 4. mannose-6P targets protein to lysosome 5. proteoglycan assemble 6. sulfation of sugars in PGs and tyr proteins |
|
|
What is I-cell dz
|
failure to add mannose6P to lysosome proteins--> proteins then secreted; sxs include coarse facial feature, clouded corneas,
|
|
|
What are the 3 primary vesicular trafficking proteins
|
COPI --- Retrograde (Golgi-->ER)
COPII -- Anterograde (RER --> cisGolgi) Clathrin -- trans Golgi --> lysosomes, PM --> endosomes |
|
|
What is the role of microtubules
|
incorporated into flagella, cilia, and mitotic spindles
involved in slow axoplasmic transport in neurons |
|
|
What are drugs that act on microtubules
|
1. Mebendazole (antihelminthic)
2. Taxol (breast Ca) 3. Griseofulvin (antifungal) 4. Vincristine (Cancer) 5. Colchicine (gout) |
|
|
What dz is due to microtubule polymerization defect leading to decreased phagocytosis
|
Chediak-Higashi (staph/strep infxn, neuropathy, albinism)
|
|
|
what is the composition of microtubules
|
alpha and beta tubulin (13 per circumference)
|
|
|
What is the structure of cilia
|
9+2 Arrangement of microtubules
|
|
|
What links the microtubules in cilia
|
Dynein (ATPase) -- retrograde
Kinesin (anterograde) |
|
|
What is Kartagener's syndrome
|
immotile cilia 2/2 dynein arm defect --> infertility, bronchiectasis and sinusitis --> situs inversus
|
|
|
Where is Type I collagen found
|
Bone, Skin, Tendon, late wound repair
|
|
|
Where is Type II collagen found
|
Cartilage, nucleus pulposus
|
|
|
Where is Type III collagen found
|
Reticulin -- skin, bv, uterus, granulation tissue
|
|
|
Where is Type IV collagne found
|
basement membrane and basal lamina
|
|
|
What is synthesis of collagen
|
RER -- alpha chains -- preprocollagen--Gly-X-Y (X and Y are proline, hydroxyproline and hydroxylysine)
|
|
|
Where does hydroxylation of collagen take place
|
in ER, hydroxylation of proline and lysine requiring vitC
|
|
|
What are the six steps of collagen synthesis
|
Synthesis (RER)
Hydroxylation of proline and lysine(ER--VitC) --> Glycosylation of lysine (Golgi-Procollagen) -- triple helix Exocytosis Proteolytic processing (terminal cleavage --> tropocollagen) Cross-linking (lys--hydroxylysin by lysyl oxidase) -- collagen fibrils |
|
|
What is Ehlers-Danlos syndrome
|
faulty collagen synthesis
1. hyperextensible skin 2. easy bruising 3. hypermobile joints Collagen III most commonly affected; a/w berry aneurysms |
|
|
What is osteogenesis imperfecta
|
Auto Dominant
gene defect in collagen synthesis (collagen type I most common) sxs: multi fx, blue sclerae, hearing loss, and dental imperfections |
|
|
What tissue stains witht eh following:
vimentin, desmin, cytokeratin, GFAP, neurofilaments |
vimentin (CT), desmin (musc), cytokeratin (epithelial cells), GFAP (neuroglia), neurofilaments (neurons)
|
|
|
What disorder involves defective elastin and fibrillin
|
Marfans (fibrillin) where elastin is tropoelastin with fibrillin scaffolding
|
|
|
What types of metabolism take place in mitochondria
|
FA Oxidation, Acetyl-CoA production, and Kreb cycle
|
|
|
What types of metabolism take place in cytoplasm
|
Glycolysis, FA synthesis, HMP shunt, Protien synth (RER), steroid synth (SER)
|
|
|
What metabolism takes place in both cytoplasm and mitochondria
|
Gluconeogenesis, urea cycle, heme sythesis
|
