Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Step 1 > Biochemistry > Flashcards

Biochemistry Flashcards

1
Q

RNA polymerase I

A

restricted to nucleolus as it synthesizes majority of rRNA

produces 18S, 5.8S, & 28S

forms essential ribosomal components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

mRNA

A

Produced by RNA pol II

translated by ribosomes to form specific proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

small nuclear RNA

A

Produced by RNA pol II

involved in mRNA splicing & transcription regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

micro RNA

A

Produced by RNA pol II

cause gene silencing via translation arrest or mRNA degradation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

RNA pol III

A

produces tRNA and 5S ribosomal RNA (essential component of 60S ribosomal subunit)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

vitamin A deficiency

A

sx = night blindness, complete blindness, xerophthalmia, Bitot’s spots (abnromal squamous cell proliferation and keratinization of conjunctiva), corneal perforation, keratomalacia, derm abnl, damage to phagocytes and TC lymphocytes, death

common in Asia, Africa, South America

associated with malnourishment and fat malabsorption (eg CF, cholestatic liver disease)

Give to all children with measles from area with vit A def or with measles mortality >1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Transformation

A

Direct uptake of naked DNA from the environment by bacT that are naturally able

  • strep pneumo
  • Haemophilus influenza
  • Neisseria gonorrhoeae & meningitidis

*this is how non-virulent non-capsule-forming strains of s. pneumo can obtain genes that code for capsule and gain virulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Conjugation

A

one-way transfer of DNA between bacT cells through direct physical contact

donor cells contain an extra segment of DNA = F factors coding for sex pilus and other prot necessary for transfer to F- recipients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transduction

A

transfer of DNA via bacteriophage

during lytic infection when random bacT genes accidentally packaged into viral capsid

lyosgenic infection when selected bacT genes near viral insertion site are excised and packaged into virion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dry beriberri

A

think ber1 ber1 –> B1 deficiency

polyneuritis, symmetrical muscle wasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Wet beriberi

A

high-output cardiac failure (dilated cardiomyopathy), edema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

B1 deficiency

A

impaired glucose breakdown –> ATP depletion worsened by glucose infusion with highly aerobic tissues affected first (brain, heart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Thiamine

A

found in thiamine pyrophosphate (TPP) = cofactor for:

  • pyruvate dehydrogenase (links glycolysis to TCA)
  • alpha-ketoflutarate dehydrogenase = TCA cycle
  • Transketolase (HMP shunt responsible for NADPH production)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

vitamin B2

A

riboflavin

cofactor in oxiation and reduction (eg FADH2)

Mneumonics:
-Fad and Fmn derived from riboFlavin (B2 = 2ATP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

B2 deficiency

A

Cheilosis
Crneal vascularization

“2 C’s of B2”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

B3

A

niacin

constituent of NAD+, NADP+ (using redox reactions).

Derived from tryptophan – need B6

“NAD derived from Niacin (B3 = 3 ATP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Niacin deficiency

A

glossitis
severe = pellagra = diarrhea, dementia, dermatitis

c/b Hartnup dz (dec tryptophan absorption), malignant carcinoid syndrome (inc tryptophan metabolism), INH (dec B6)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

niacin excess

A

flushing - seen at doses used to tx HLD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

B5 function and deficiency presentation

A

pantothenate

essential part of CoA and fatty acid synthase

deficiency = dermatitis, enteritis, alopecia, adrenal insufficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

B6

A

pyridoxine

converted to pyridoxal phosphate = cofactor used in transamination (ALT, AST), decarboxylation reactions, glycogen phosphorylase

Needed to make:

  • cystathionine
  • heme
  • niacin
  • histamine
  • NTs = 5HT, E, NE, GABA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

B6 deficiency

A

convulsions, hyperirritability, peripheral neuropathy, sideroblastic anemia due to impaired Hb synthesis and iron excess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

B7 (biotic)

A

cofactor for carboxylation enzymes (add 1-carbon group):

  • pyruvate carboyxlase: pyruvate (3C) –> oxaloacetate (4C)
  • acetyl-CoA carboxylase: acetyl-CoA (2C) –> malonyl-CoA (3C)
  • Propionyl-CoA carboxylase: propionyl-CoA (3C) –> methylmalonyl-CoA (4C)

deficiency is rare but causes dermatitis, alopecia, enteritis. Occurs if consume too many raw eggs (Avidin binds biotin) or abx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

B9

A

converted to tetrahydrofolate (THF) = coenzyme for 1-C transfer/methylation rxns

needed to make nitrogenous bases in DNA and RNA

found in green leafy vegetables (“folate in foliage”)

small reserve pool in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

drugs that cause folate deficiency

A

MTX, phenytoin, sulfonamides

*remember no neuro sx like in B12 deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

B12

A

cofactor for homocysteine methyltransferase (transfers methyl group as methylcobalamin) and methylmalonyl-CoA mutase

large reserve in liver that lasts years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

B12 deficiency

A

malabsorption (sprue, enteritis, diphyllobothrium latum), lack intrinsic factor, absent terminal ileum

dx with Schilling test

findings = macrocytic, megaloblastic anemia, hypersegmented PMNs, neuro sx (paresthesias) due to abnomral myelin, if prolonged get irreversible nervous system damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Kwashiorkor

A

protein deficient MEAL-

Malnutrition
Edema
Anemia
Liver (fatty due to dec apolipoprotein synthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Marasmus

A

Muscle wasting
loss of SQ fat
variable edema

c/b energy malnutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what 3 things are metabolized in both the cytosol and mito.?

A

HUGs take 2

Heme
Urea cycle
Gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What 5 cofactors are needed for the pyruvate dehydrogenase complex?

A
  1. Pyrophosphate (B1, thiamine, TPP)
  2. FAD (riboflavin, B2)
  3. NAD (niacin, B3)
  4. CoA (pantothenate, B5)
  5. Lipoic acid

Goal = pyruvate + NAD+ + CoA –> acetyl-CoA + CO2 + NADH

preparing for TCA cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Regulation by Fructose-2,6-bisphosphate in the fasting state

A

inc glucagon –> inc cAMP –> inc protein kinase A –> inc fructose bisphosphatase-2, dec PFK-2, less glycolysis

Remember:

  • fasting means you’re low on E –> get back the phosphate to produce glucose/energy
  • going from F2,6BP to F6P
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Regulation by Fructose-2,6-bisphosphate in the fed state

A

inc insulin –> dec cAMP –> dec protein kinase A –> dec FBPase-2, inc phosphofructokinase-2, more glycolysis

Remember:

  • you’re fed, have to energy to spare, add phosphates to things
  • “energy to burn, don’t give a fructo” – phosphoFRUCTOkinase-2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are the 2 purely ketogenic amino acids

A

Lysine and Leucine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

mutation in pyruvate dehydrogenase complex deficiency

A

x-linked gene for E1-alpha subunit

sx = neuro deficits
tx = ketogenic diet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

4 possible targets of pyruvate metabolism and effector enzyme:

A
  1. ALT (with B6): alanine carries amino groups to liver from muscle
  2. pyruvate carboxylase (with B7): oxaloacetate replenishes TCA cycle or used in gluconeogenesis
  3. pyruvate dehydrogenase (B1, B2, B3, B5, lipoid acid): transition from glycolysis to the TCA cycle
  4. Lactic acid dehydrogenase (B3): end of anaerobic glycolysis (RBCs, leukocytes, kidney medulla, lens, testes, cornea)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

alpha-ketoglutarate dehydrogenase complex

A

same cofactors as pyruvate dehydrogenase complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Citric acid cycle major players in order mneumonic

A

“Citrate Is Kreb’s Starting Substrate For Making Oxaloacetate”

Citrate 6C
Isocitrate 6C
alpha-ketoglutarate 5C
Succinyl-CoA 4C
Succinate 4C
Fumarate 4C
Malate 4C
Oxaloacetate 4C
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Products of TCA cycle

A

3 NADH
1 FADH2
2 CO2 –> from the C decreases, i.e. 6C -> 5C -> 4C
1 GTP per acetyl-coA

Total: 10 ATP/acetyl-CoA (multiply by 2 for each glucose since it produces 2 acetyl-CoA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Electron transport inhibitors

A

inhibit Complexes of transport chain dec proton gradient and blocking ATP synthesis

Rotenone –| Complex I
Antimycin A –| Complex III
Cyanide and CO –| Complex IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

ATP synthase inhibitors

A

directly inhibit mito ATPsynthase causing inc proton gradient. No ATP produced bc electron transport stop

Oligomycin –| Complex V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Uncoupling agent of e- transport chain

A

inc permeability of membrane –> dec proton gradient and inc O2 consumption –> ATP synthesis stops but e- transport produces heat

2,4-DNP, aspirin (fever recurs after overdose), thermogenin in brown fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Which tissue can’t do gluconeogensis and why?

A

muscle bc it lacks G6P enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which fatty acid chains can produce glucose?

A

Odd chains becaues they yield 1 propionyl-CoA which can enter the TCA cycle as succinyl-CoA

Even chains can’t bc only make acetyl-CoA equivalents

“Odd FAtty’s have Energy thanks to their PROPortionality”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the end product of the HMP shunt (pentose phosphate pathway)?

A

ribose for nucleotide synthesis and glycolytic intermediates

No ATP is used or produced

Sites: lactating mammary glands, liver, adrenal cortex (sites of FA and steroid synthesis), RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the end product of oxidative (irreversible) HMP shunt?

A

CO2, 2 NADPH, Ribulose-5-Pi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the end product of nonoxidative (reversible) HMP shunt?

A

Ribose-5-Pi, G3P, F6P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the action of NADPH oxidase and where is it located?

A

rapid release of reactive oxygen intermediates and found in neutrophils and monocytes

NADPH plays a role in the creation of ROIs and their neutralization –> important for immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What type of infections are patients with chronic granulomatous disease at risk for and why?

A

catalase positive species like s. aureus or aspergillus bc catalase neutralizes the bactericidal effect of H2O2

normally CGD pts use the H2O2 generated by invading organisms and convert it to ROIs but they can’t do that with catalase-positive species bc the catalase will just breakdown the H2O2 made by the organism, i.e. it breaks down its own H2O2 metabolism byproduct

49
Q

deficiencies in glycolytic enzymes leads to…

A

hemolysis bc RBCs depend solely on glycolysis for their energy needs

50
Q

Glucose-6-Phosphate Deficiency

A
  • X-linked recessive disorder
  • the most common glycolytic deficiency (and human enz def overall)
  • more prevalent in blacks
  • inc malarial resistance

RBCs can’t phosphorylate glucose –> don’t carry out glycolysis –> RBC protected from oxidative stress by glutathione –> glutathione regeneration dependent on NADPH produced by glycolysis and HMP shunt neither of which happening –> Hb denatured –> Heinz bodies

*exacerbated by fava beans

51
Q

Glutathione

A

in reduced form detoxifies free radicals and peroxides, i.e. protects from oxidizing agents

(eg fava beans, sulfonamides, primaquine, antituberculosis drugs)

52
Q

which two pathways can give starting substrate of glycolysis (glyceraldehyde-3-P)?

A

Glucose metabolism

Fructose metabolism

53
Q

Fructose metabolism pathway

A

fructose –fructokinase–> fructose-1-P –aldolaseB–> dihydroxyacetone-P and glyceraldehyde –triose kinase–> Glyceraldehyde-3-P

deficiency in fructokinase = essential fructosuria, AR, benign, asx, fructose found in blood and urine

deficiency in aldolase B = AR, fructose-1-P accumulates causing a dec in available phosphate –> inhibition of glycogenolysis and gluconeogenesis

  • sx = jaundice, hypoglycemia, cirrhosis, vomiting
  • tx = no fructose or sucrose (gluc + fruc)
54
Q

d/o of fructose and galactose metabolism mneumonic

A

Fructose is to Aldolase B as Galactose is to UridylTransferase

FAB GUT

these are the two more serious defects because they lead to PO4 depletion (in comparison to essential fructose intolerance from defective fructokinase and galactoskinas deficiency)

55
Q

glycolysis and gluconeogenesis dependent on metabolism of what?

A

galactose

56
Q

uridyl transferase

A

galactose metabolism

converts galactose-1-P to glucose 1-P with help of 4-epimerase

57
Q

4-epimerase

A

galactose metabolism UDP-Gal converted to UDP-Glu facilitating uridyl transferase conversion of galactose-1-P to glucose-1-P to be used in glycolysis and gluconeogenesis

58
Q

Alternative method of trapping glucose in cells?

A
  • convert it to alcohol counterpart, i.e. sorbitol
  • done via aldose reductase
  • liver, lens, ovaries, and seminal vesicles also have sorbitol dehydrogenase which converts sorbitol to fructose
  • schwann cells, retina, kidneys have only aldose reductase –> risk for sorbitol accumulation and osmotic damage (cataracts, retinopathy, peripheral neuropathy)

*happens with excess galactose too

59
Q

Essential amino acids

A

Glucogenic: Met, Val, His

Glucogenic/ketogenic: Ile, Phe, Thr, Trp

Ketogen: Leu, Lys

60
Q

Acidic aa

A

Asp and Glu (negatively charged at body pH)

61
Q

Basic aa

A

Arg, Lys, His

Arg = most basic, "Argyle print is so basic"
His = no charge at body pH, "His style is so neutral"

Arg + His = needed during time of growth bc they are inc in histones wrapped around DNA

62
Q

Urea cycle

A

“Ordinarily, Careless Crappers Are Also Frivolous About Urination”

Ornithine
Carbamoyl phosphate (made in mito., then out to cyto.)
Citruline
Aspartate - donates NH4+ to make urea 
Argininosuccinate
Arginine                    + Fumarate
Urea

urea = made in liver, excreted by kidneys

63
Q

Role of alanine and glutamate in ammonium transport

A

muscle cell:

  • amino acids broken down to alpha-ketoacids
  • end up with glutamate that together with pyruvate give alanine

Alanine cycle:
-alanine transported to liver where in combination with alpha-ketoglutarate you get glutamate again and then you make urea

*Cori cycle: glucose -> pyruvate -> lactate in muscle cell –> move to liver as lactate -> pyruvate -> glucose –> back to muscle as glucose and repeat

64
Q

how do you develop hyperammonemia

A

acquired in liver disease (e.g. cirrhosis)
hereditary via urea cycle enzyme deficiency

problem is excess NH4+ deplete alpha-ketoglutarate (which is part of the alanine and glutamate transport of urea cycle) –> inhibit TCA cycle

sx = tremor (asterixis), slurring of speech, somnolence, vomiting, cerebral edema, blurring vision –> basically symptoms of an alcoholic

tx = limit protein in diet, benzoate or phenylbutyrate (bind aa and lead to excretion), lactulose

65
Q

Most common urea cycle disorder

A

Ornithine transcarbamoylase deficiency which is what combines ornithine with carbamoyl phosphate to make citruline

x-linked recessive (all other urea enz def are AR)

end up with excess carbamoyl phosphate in mito. which is then converted to orotic acid (part of pyrimidine synthesis pathway)

sx = inc orotic acid in blood and urine, dec BUN, sx of hyperammonemia (asterixis, somnolence, vomiting, cerebral edema, blurring vision).

66
Q

Phenylalanine derivatives

A

–BH4–> Tyrosine (-> Thyroxine) –BH4–> Dopa (-> melanin) –vitB6–> dopamine –vitC–> NE –SAM–> Epi

67
Q

Tryptophan derivatives

A

via B6 get Niacin –> NAD+/NADP+

via BH4 get Serotonin –> melatonin

68
Q

Histidine derivative

A

via B6 –> histamine

69
Q

Glycine derivatives

A

via B6 –> porphyrin –> heme

70
Q

Arginine derivatives

A

Creatine
Urea
Nitric oxide

71
Q

Glutamate derivatives

A

via B6 GABA

Glutathione

72
Q

Enzymes to know involved in catecholamine synthesis and tyrosine catabolism

A
  1. Phenylalanine hydroxylase - PKU
  2. Tyrosine hydroxylase
  3. Dopa decarboxylase
  4. Dopamine beta-hydroxylase
  5. Phenylethanolamine N-methyltransferase
73
Q

Phenylketonuria

A

defective or absent phenylalanine hydroxylase ==> Tyrosine is now an essential amino acid

inc Phe leads to excess phenylketones in urine

findings: ID, growth retardation, seizures, fair skin, eczema, musty body odor (d/o aromatic aa metabolism –> body odor)
tx: dec Phe in diet and inc tyrosine

74
Q

Findings in newborn with maternal PKU

A

c/b lack of proper diet during pregnancy

microcephaly, ID, growth retardation, congenital heart defects

75
Q

Alkaptonuria (ochronosis)

A

congenital deficiency of homogentisic acid oxidase in degradative pathway of tyrosine to fumarate

AR, benign disease

findings; dark connective tissue, brown pigmented sclera, urine turns black on prolonged exposure to air, debilitating arthralgia (homogentisic acid is toxic to cartilage)

76
Q

Albinism

A

c/b deficiency in either:

  • tyronsinase = AR, can’t make melanin from tyrosine
  • defective tyrosine transporters = dec tyr and therefore dec melanin

due to lack of migration of neural crest cells

77
Q

Homocystinuria forms

A

all AR, the main problem is excess homocysteine and no cysteine so it cystein becomes essential

  1. Cystathionine synthase deficiency: needed for conversion of homocys to cystathionine and then to cys
    - tx dec Met and inc Cys and inc B12 and folate in diet
  2. dec affinity of cystathionine synthase for pyridoxal phosphate, i.e. B6 cofactor
    - tx inc vit B6 in diet
  3. homocysteine methyltransferase (requires B12) deficiency: needed to convert homocys to methionine
    findings: inc homocysteine in uria, ID, osteoporosis, tall stature, kyphosis, lens subluxation (down and in) and atherosclerosis (stroke and MI)
78
Q

Cystinuria

A

AR defect of renal tubular amino acid transporter for cysteine, ornithine, lysine and arginine in kidney PCT

excess cys in urine –> precipitation –> staghorn calculi

Tx: hydration, urine alkalinization

79
Q

Maple syrup urine disease

A

AR, urine smells like maple syrup
“I Love Vermont maple syrup from maple tress with branches”

dec alpha-ketoacid dehydrogenase (B1) –> blocked degradation of branched amino acids (Ile, Leu, Val) –> inc alpha-ketoacids in blood, esp Leu

sx = CNS defects, ID, death

80
Q

Hartnup disease

A

AR

defective neutral amino acid transporter on renal and intestinal epithelial cells –> tryptophan excretion and dec absorption in the gut

remember tryptophan –> niacin therefore deficiency in tryp leads to niacin deficiency, a.k.a. PELLAGRA

81
Q

Glycogen storage disorders

A

12 types

abnormal glycogen metabolism –> accumulation in cells

82
Q

Type 1 Glycogen Storage Disease = von Gierke’s Disease

A

AR, glucose-6-phosphatase deficiency

severe fasting hypoglycemia, inc glycogen in liver, inc blood lactate, hepatomegaly

83
Q

Type 2 Glycogen Storage Disease = Pompe’s disease

A

AR, Pome’s trashes the Pump (heart, liver, muscle)

lysosomal alpha-1,4-glucosidase (acid maltase) deficiency which is normally supposed to degrade small amount of glycogen

cardiomegaly and systemic findings leading to early death

84
Q

Type 3 Glycogen Storage Disease = Cori’s disease

A

AR, gluconeogensis intact, debranching (alpha-1,6-glucosidase) deficiency

milder form of type I with normal lactate levels in blood

85
Q

Type 4 Glycogen Storage Disease = McArdle’s disease

A

AR, McArdle’s = Muscle

skeletal muscle glycogen phosphorylase deficiency

inc glycogen in muscle but can’t break it down –> painful muscle cramps and myoglobinuria with strenuous exercise

86
Q

Gaucher’s disease

A

most common lysosomal storage disorder

Deficient Enzyme: Glucocerebrosidase
Accumulated Substrate: Glucocerebroside
Inheritance: AR

Findings:
HSM, aseptic necrosis of femur, bone crises, Gaucher’s cells (macrophages that look like crumpled paper)

87
Q

Niemann-Pick disease

A

Deficient Enzyme: sphingomyelinase
Accumulated Substrate: sphingomyelin
Inheritance: AR

Findings:
progressive neurodegeneration, HSM, CHERRY-RED spot on macula, foam cells

88
Q

Tay-Sachs disease

A

Deficient Enzyme: Hexosaminidase A
Accumulated Substrate: GM2 ganglioside
Inheritance: AR

Findings:
progressive neurodegeneration, developmental delay, cherry-red spot on macula, lysosomes with onion skin, no HSM (as compared to Niemann Pick)

89
Q

Krabbe’s disease

A

Deficient Enzyme: Galactocerebrosidase
Accumulated Substrate: Galactocerebroside
Inheritance: AR

Findings:
peripheral neuropathy, development delay, optic atrophy, globoid cells

90
Q

Metachromatic leukodystrophy

A

Deficient Enzyme: arylsulfatase A
Accumulated Substrate: cerebroside sulfate
Inheritance: AR

Findings:
central and peripheral demyelination with ataxia, dementia

91
Q

Hurler’s syndrome

A

Mucopolysaccharidoses - missing lysosomal enzymes required to break down glycoaminoglycans

Deficient Enzyme: alpha-L-iduronidase
Accumulated Substrate: heparan sulfate, dermatan sulfate
Inheritance: AR

Findings:
developmental delay, gargoylism, airway obstruction, corneal clouding, HSM

92
Q

Hunter’s syndrome

A

Mucopolysaccharidoses - missing lysosomal enzymes required to break down glycoaminoglycans

Deficient Enzyme: Iduronate sulfatase
Accumulated Substrate: heparan sulfate, dermatan sulfate
Inheritance: XR

Findings:
Mild Hurler’s + aggressive behavior, no corneal clouding (Remember it as qualities of a hunter who has to see clearly)

93
Q

Fatty acid synthesis

A

inner mitochondrial membrane

citrate in mito matrix

“SYtrate = SYnthesis”

94
Q

Fatty acid degradation

A

inner mitochondrial membrane

carnitine brings fatty acids and CoA in from cytosol

“CARnitine = CARnage of fatty acids”

95
Q

carnitine deficiency

A

inability to transport long chain fatty acids to mitochondria –> toxic accumulation –> weakness, hypotonia, hypoketotic hypoglycemia

96
Q

acyl-CoA dehydrogenase deficiency

A

inc dicarboxylic acids, dec glucose and ketones

97
Q

number of kcal in 1 g of protein or carb

A

4

98
Q

number kcal in 1 g of fat

A

9

99
Q

pancreatic lipase

A

degradation of dietary TG in small intestine

100
Q

Lipoprotein lipase (LPL)

A

degradation of TG circulating in chylomicrons and VLDLs

101
Q

Hepatic TG lipase (HL)

A

degradation of TG remaining in IDL

102
Q

Hormone-sensitive lipase

A

degradation of TG stored in adipocytes

103
Q

Lecithin-cholesterol acyltransferase (LCAT)

A

catalyzes esterification of cholesterol, i.e. nascent HDL to mature HDL

104
Q

Cholesterol ester transfer protein (CETP)

A

mediates tranfer of cholesterol esters to other lipoproteins particles , i.e. to VLDL, IDL, LDL

105
Q

Apolipoprotein E

A

carrier protein

recognized by hepatocytes –> allows liver to remove chylomicron remnants from blood

found in chylomicron, chylomicron remnant, VLDL, IDL, HDL

106
Q

Apoliprotein B-48

A

necessary for chylomicrons to be released into the blood from intestinal cells

107
Q

Apolipoprotein A-I

A

activates lecithin-cholesterol acyltransferase (LCAT)

108
Q

Apolipoprotein C-II

A

lipoprotein lipase cofactor

109
Q

Apolipoprotein B-100

A

binds LDL receptor

110
Q

LDL

A

transports cholesterol from Liver to Tissues

111
Q

HDL

A

transports cholesterol from tissues to liver

112
Q

type 1 hyperchylomicronemia

A

inc blood chylomicrons, TG, cholesterol

AR, lipoprotein lipase deficiency or altered apolipoprotein C-II

causes pancreatitis, HSM, and eruptive/pruritic xanthomas (no inc risk for atherosclerosis)

113
Q

type 2a familial hypercholesterolemia

A

inc LDL, cholesterol in blood

AD

absent or dec LDL receptors

accelerated atherosclerosis, tendon (Achilles) xanthomas, corneal arcus

114
Q

type 4 hypertriglyceridemia

A

inc VLDL and TG in blood

AD

hepatic overproduction of VLDL
causes pancreatitis

115
Q

abetalipoproteinemia

A

AR mx in microsomal TG transfer protein (MTP) gene –> dec B-48 and B-100 –> dec chylomicron and VLDL synthesis and secretion

sx first few months of life

findings: failure to thrive, steatorrhea, acanthocytosis, ataxia, night blindness

116
Q

Gq 2nd messenger pathway

A

GPCR-Gq stimulation –> Phospholipase C –> splits lipids into PIP2 –> PIP2 split into DAG (activates Protein kinase C) and IP3 (inc Ca2+ concentration and causes smooth muscle contraction)

117
Q

Gs 2nd messenger pathway

A

GPCR-Gs stimulation –> adenylyl cyclase –> converts ATP to cAMP –> activates protein kinase A –> inc [Ca2+] in heart cells, inhibits myosin light-chain kinase in smooth muscle

118
Q

Gi 2nd messenger pathway

A

inhibits the G2 pathway:

inhibits adenylyl cyclase and the downstream effects (–> converts ATP to cAMP –> activates protein kinase A –> inc [Ca2+] in heart cells, inhibits myosin light-chain kinase in smooth muscle)

Step 1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions