Proteins, Enzymes, Membranes and Signal Transduction EC Flashcards Preview

Evan's Step 1 Prep Material > Proteins, Enzymes, Membranes and Signal Transduction EC > Flashcards

Flashcards in Proteins, Enzymes, Membranes and Signal Transduction EC Deck (40):
1

Cystinuria

Autosomal Recessive
Defect in basic amino acid transporter (Cystine, Lysine, Arginine) in renal tubules
Excessive excretion and formation of cystine kidney stones

2

Hartnup's Disease

Autosomal Recessive
Pellagra like (diarrhea, dermatitis, dementia)
Defective absorption of tryptophan

3

Gs Receptor function and coupled receptors

Stimulate Adenylate Cyclase (increase cAMP --> PKA)

Dopamine (D1)
Epinephrine (B1,B2)
Glucagon histamine (H2)
Vasopressin (V2)

4

Gi Receptor function and coupled receptors

Inhibit adenylate cyclase (decrease cAMP)

Dopamine (D2)
Epinephrine (a2)

5

Gq Receptor function and coupled receptors

Stimulates phospholipase C (increased IP3 & DAG)

Angiotensin II
Epinephrine (a1)
Oxytosin
Vasopressin (V1)

*phosphorylated myosin light chains --> SM contraction*

6

Gt receptor function and coupled receptors

Stimulate cGMP phosphodiesterase (increase cGMP)

Rhodopsin (light sensitive)

7

Tyrosine Kinase overview (insulin receptor as example)

Insulin binds TK--> autophosphorylation
IRS-1 activates . . .
RAS/MAP kinase (long-term effects-gene expression) and
PKB (short term effects-increased GLUT-4)

8

Cholera/EHEC toxins

Permanently activate Gs (ADP-ribosylation)
Increased cAMP
Loss of isotonic fluid
Diarrhea

9

Pertussis toxin

Permanently inactivates Gi (ADP-ribosylation)
Increased cAMP
Increased mucus secretion in respiratory tract (whooping cough)

10

Ephedrine MOA and use

alpha-1 agonist

Vasoconstriction (decongestant)

11

Albuterol and Terbutaline MOA and use

Beta-2 agonists

Bronchodilation (asthma)

12

Beta blockers MOA and use

decrease BP

precipitate asthma

13

Losarton MOA and use

Angiotensin II antagonist

Lowers BP

14

Chlorpromazine/Haloperidol MOA and use

D2 antagonists

Antipsychotics

15

Niacin as a co-enzyme

NAD+ (nicotine adenine dinucleotide)
REDOX reactions (ie. glycolytic pathway)

16

Pyridoxine as a co-enzyme

Pyridoxal phosphate
TRANSAMINATION reactions (ie. alanine to pyruvic acid)

17

Thiamine as a co-enzyme

DECARBOXYLATION (ie. degradation of branched chain amino acids)

Transketolase (2-carbon transfer in pentose-phosphate-pathway)

18

Biotin as a co-enzyme

CARBOXYLATION

19

Folic acid as a co-enzyme

THF (tetra-hydro-folate)
One carbon transfers (ie. serine --> glycine)

20

Magnesium as co-factor

Kinases

21

Zinc as a co-factor

Carbonic anhydrase
Collagen
Alcohol dehydrogenase
Superoxide dismutase

22

Copper as a co-factor

Oxidases (lysyl oxidase in collagen cross-linking)
Ferroxidase (Fe3+-->Fe2+)
Cytochrome c oxidase (electrons to O2 to make water)

23

Iron as a co-factor

Cytochromes

24

Selenium as a co-factor

Glutathione peroxidase

25

Zero-Order Reaction

Velocity independent of [Substrate]

Saturated

26

First-Order Reaction

Velocity dependent on [Substrate]

Below Km

27

Alanine aminotransferase (ALT) diagnostic use

Viral hepatitis (ALT>AST)

28

Aspartate aminotransferase (AST) diagnostic use

Alcoholic hepatitis (AST>ALT)

MI (AST only)

29

Alkaline phosphatase diagnostic use

Osteoblastic bone disease
Metastatic prostate cancer
Obstructive liver disease

30

Amylase diagnostic use

Acute pancreatitis (lipase more specific)
Mumps (parotitis)

31

Creatine Kinase (CK) diagnostic use

MI (CK-MB)
DMD (CK-MM)

32

gamma-glutamyl transferase (GGT) diagnostic use

Obstructive liver disease
Alcoholics (increased)

33

Lactate dehydrogenase (LDH)

MI

34

Lipase

Acute pancreatitis (more specific than amylase)

35

What form of Fe binds O2?

Fe2 binds O2

36

What is methemoglobin?

Hgb with Fe3+
CANNOT BIND O2

37

What does a left shift in the O2 binding curve mean?

Increased Hgb affinity for O2 (loading)

38

What does a right shift in the O2 binding curve mean?

Decreased Hgb affinity for O2 (UNloating)

Causes:
decreased O2 binding
2,3 BPG (response to high altitude)
H+/CO2
Increased tempterature

39

What is the mechanism by which CO2 effects hemoglobin binding?

Conversion by carbonic anhydrase decreases pH
Protonation of histidine residues
DECREASED AFFINITY FOR O2

40

Slate grey cyanosis in infant without pulmonary or cardiac disease

Hereditary methemoglobinemia (HgM)

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