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Step 1 Complete > Biochem 1 USMLE > Flashcards

Biochem 1 USMLE Flashcards

1
Q

full-term neonate of uneventful delivery becomes mentally retarded and hyperactive and has a musty odor. What is the d?

A

PKU

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2
Q

Stressed executive comes home from work, consumes 7 or 8 martinis in rapid succession before dinner, and becomes hypoglycemic. What is the mechanism?

A

NADH increase prevents gluconeogenesis by shunting pyruvate and oxaloacetate to lactate and malate

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3
Q

2 y/o girl has an increase in abd girth, failure to thrive and skin and hair depigmentation. What is the dx

A

kwashiorkor

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4
Q

alcoholic develops a rash, diarrhea, and altered mental status. What is the vitamen deficiency

A

vit B3 (pellagra)

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5
Q

51 y/o man has black spots in his sclera and has noted that his urine turns black upon standing. What is the dx

A

alkaptonuria

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6
Q

25 y/o male complains of severe chest pain and has xanthomas on his achilles tendons. What is the dz, and where is the defect?

A

familial hypercholesterolemia; LDL receptor

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7
Q

Condensed by (-) charged DNA looped twice around (+) charged H2A, H2B, H3, & H4 histone octamers (nucleosome bead). H1 ties nucleosmes together on a string (30-mm fiber). In mitosis, DNA condenses to form mitotic chromosomes.

A

Chromatin sx–image 77

note: Think of beads on a string

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8
Q

this type of chromatin is condensed, transcriptionally inactive

A

heterochromatin

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9
Q

this type of chromatin is less condensed, transcriptionally active

A

euchromatin

eu=true, “truely transcribed.”

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10
Q

purines are _____ & _____ and have _____ ring/s.

pyramidines are _____,_____, &______

A

A,G (2 rings)
C,T,U (1 ring)

mneu: PURe As Gold: PURines.
CUT the PY (pie)

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11
Q

Guanine has a _______

A

ketone

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12
Q

Thymine has a ______

A

methyl

mneu: THYmine has a meTHYl

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13
Q

Deamination of cytosine makes a _____

A

uracil

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14
Q

uricil is found in this nucleic acid

A

RNA

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15
Q

thymine is found in this nucleic acid

A

DNA

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16
Q

This bond has 3 H bonds and is therefore stronger that this bond which only has 2 H bonds

A

G-C bond > A-T

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17
Q

nucleotides with a higher G-C means a higher this

A

melting temperature

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18
Q

nucleotides are linked by this type of bond

A

3’-5’ phosphodiesterase bond

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19
Q

this refers to substituting purine for purine or pyrimidine for pyrimidine

A

transition

mneu: TransItion=Identical types

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20
Q

this refers to substituting purine for a pyrimidine or pyrimidine for purine

A

Transversion

mneu: TransVersion=conVersion between types

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21
Q

this feature of the genetic code refers to the fact that each codon specifies only 1 amino acid

A

unambiguous

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22
Q

this feature of the genetic code refers to the fact that more than 1 codon may code for the same amino acid

A

degenerate

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23
Q

the genetic code is universal (exceptions include mitochondria, archaeobacteria, mycoplasma, and some yeast) T or f

A

T

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24
Q

this mutation in dna often involves the same AA, it is often a base change in the 3rd position of codon (tRNA wobble).

A

silent

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25
Q

this mutation in dna involves a changed AA (conservative-new AA is similar in chemical sx)

A

missense

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26
Q

this mutation in dna often involves a change resulting in an early STOP CODON

A

nonsense

mneu: stop the nonsense

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27
Q

this mutation in dna often involves a change resulting in misreading of all nucleotides downstream, usually resulting in a truncated protein

A

frame shift

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28
Q

Single origin of replication in prokaryotic DNA replication by DNA polymerases refers to ________ DNA synthesis on the leading strand and _______ on the lagging strand

A

Continuous

Discontinuous (Okazaki fragments)

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29
Q

DNA polymerase III has ____ synthesis and proofreads with ______ exonuclease

A

5’->3’

3’->5’

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30
Q

DNA polymerase I excises RNA primer with ____ exonuclease

A

5’-3’

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31
Q

these create a nicks in the helix to relieve supercoils

A

DNA topoisomerase

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32
Q

this makes an RNA primer on which DNA polymerase III can initiate replication

A

Primase

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33
Q

this elongates the chain by adding deoxynucleotides to the 3’ end until it reaches primer of preceding fragment. 3’ ->5’ exonuclease activity “profreads” each added nucleotide.

A

DNA polymerase III

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34
Q

this degrades RNA primer

A

DNA polymerase I

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35
Q

this seals

A

DNA ligase

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36
Q

eukaryotic genome has _____ origins of replications

A

multiple

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37
Q

replication begins at a consensus sequence of ____ base pairs

A

AT

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38
Q

eukaryotes have seperate polymerases ______ for synthesizing RNA primers, leading-strand DNA, mitochondrial DNA, and DNA repair

A

(αβδγε)

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39
Q

describe DNA repair of single strand

A

single strand, excision repair-specific glycosylase recognizes and removes damaged base. Endonuclease makes a break several bases to the 5’ side. Exonuclease removes a short stretch of nucleotides. DNA polymerase fills gap. DNA ligase seals.

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40
Q

DNA repair defects regarding skin sensitivity to UV light results in this dz

A

xeroderma pigmentosum

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41
Q

DNA repair defects regarding x-rays results in this dz

A

ataxia-telangiectasia

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42
Q

DNA repair defects regarding radiation results in this dz

A

Bloom’s syndrome

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43
Q

DNA repair defects regarding cross-linking agents results in this dz

A

Fanconi’s anemia

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44
Q

xeroderma pigmentosum is this inheritance

A

autosomal recessive

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45
Q

XP results in defective excision repair such as uvr ABC endonuclease. It results in inability to repair _____, which form in DNA when exposed to UV light.

A

thymidine dymers [image p. 79]

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46
Q

XP is associated w/ these things

A

dry skin, melanoma, & other CA

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47
Q

DNA & RNA are both synthesized in this direction

A

5’ ->3’

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48
Q

The 5’ of the incoming nucleotide bears the ______ . The 3’ hydroxyl of the nascent chain is the target

A

triphosphate (energy source for bond

mneu: Imagine the incoming nucleotide bringing a gift (triphosphate) to the 3’ host. “BYOP (phosphate) from 5 to 3”

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49
Q

Protein synthesis procedes in this direction

A

5’ ->3’

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50
Q

amino acids are linked in this way

A

N to C

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51
Q

mRNA is the _____ type of RNA

rRNA is the most _____ type of RNA

tRNA is the ______ type of RNA

A

massive, Rampant, Tiny

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52
Q

In prokaryotes this makes all 3 kinds of RNA

A

RNA polymerase

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53
Q

In eukaryotes, ________ makes rRNA

A

RNA polymerase I

mneu: I,II, III are numbered as their products are used in protein sythesis

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54
Q

In eukaryotes, ________ makes mRNA

A

RNA polymerase II

mneu: I,II, III are numbered as their products are used in protein sythesis

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55
Q

In eukaryotes, ________ makes tRNA

A

RNA polymerase III

mneu: I,II, III are numbered as their products are used in protein sythesis

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56
Q

eukaryotic RNA polymerase has no ________ fx, but can initiate chains

A

proofreading fx

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57
Q

RNA polymerase II opens DNA at _________

A

promoter site (A-T rich upstream sequence —TATA and CAAT).

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58
Q

this poison is found in death cap mushrooms and works by inhibiting RNA polymerase II

A

alpha-amantin

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59
Q

what is the mRNA initiation codon

A

AUG (or rarely GUG)

mneu: AUG inAUGurates protien synthesis

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60
Q

in eukaryotes AUG codes for this, which may be removed before translation is completed

A

methionine

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61
Q

in prokaryotes the initial AUG codes for ________

A

formyl-methionine (fmet)

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62
Q

Give stop codons

A

UGA,UAA,UAG

mneu: U Go Awau, U Are Away, U Are Gone

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63
Q

In the regulation of gene expression, this is the site where RNA polymerase and multiple other transcription factors bind to DNA upstream from gene locus

A

promotor

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64
Q

promoter mutation commonly results in this

A

dramatic decrease in amount of gene transcribed

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65
Q

In the regulation of gene expression, stretch of DNA that alters gene expression by binding transcription factors. May be located close to, far from, or even within (in an intron) the gene whose expression it regulates

A

enhancer

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66
Q

In the regulation of gene expression, this is the site where negative regulators (repressors) bind.

A

operator

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67
Q

These contain actual genetic information coding for proteins

A

exons [image p. 80]

mneu: INtrons stay IN the nucleus, whereas EXons EXit and are EXpressed

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68
Q

These are intervening noncoding segments of DNA

A

introns

mneu: INtrons stay IN the nucleus, whereas EXons EXit and are EXpressed

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69
Q

Introns are precisely spliced out of primary mRNA transcripts. A lariat-shaped intermediate is formed. ___________ facilitate splicing by binding to primary mRNA transcripts and forming splicosomes.

A

small nuclear ribonucleoprotein particles (snRNP)

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70
Q

RNA processing in eukaryotes occurs in the _______, after transcription.

A

nucleus

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71
Q

only _______ is transported out of the nucleus

A

processed RNA

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72
Q

describe RNA processing in eukaryotes (3 steps)

[image p. 80]

A

1) capping on 5’ end (7-methyl-G)
2) Polyadenylations on 3’ end (-200 As)
3) Splicing out of introns

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73
Q

what is the initial transcript of RNA processing (eukaryotes) called

A

heterogeneous nuclear RNA (hnRNA)

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74
Q

capped and tailed transcript is called _______

A

mRNA

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75
Q

tRNA sx consists of 75-90 nucleotides, cloverleaf form, anticodon end is opposite 3’ aminoacyl end. All tRNAs, both eukaryotic and prokaryotic, have CCA 3’ end along w/ a high percentage of chemically modified bases. The amino acid is covalently bound to the ___ end of the tRNA.

A

3’

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76
Q

1 of these is used up per AA, it uses ATP and scrutinizes AA before and after it binds to tRNA. If incorrect, bond is hydrolyzed. The AA-tRNA bond has energy for formation of peptide bond.

A

Animoacyl-tRNA synthetase

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77
Q

A mischarged tRNA reads usual codon but inserts the ______

A

wrong AA

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78
Q

___________ and binding of charged tRNA to the codon are responsible for accuracy of amino acid selection

A

aminoacyl-tRNA synthetase

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79
Q

this describes how accurate base parining is required only in the 1st 2 nucleotide positions of an mRNA codon, so codons differing in the 3rd position may code for the same tRNA/amino acid

A

tRNA wobble

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80
Q

In ribosome protein synthesis Met sits in the ______ site

A

P site(peptidyl)

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81
Q

In ribosome protein synthesis, the incoming amino acid binds to the _____ site, hydrolyzing Met’s bond to its tRNA while simulatneously forming a peptidyl bond between 2 amino acids.

A

A site (aminoacyl)

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82
Q

The ribosome shifts 1 codon towards the 3’ end of the mRNA, shifting the uncharged tRNA into the __ position and the dipeptidyl tRNA into the __ site

A

E

P

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83
Q

ATP is used for this with tRNA

A

Activation (charging)

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84
Q

GTP is used for this with tRNA

A

Gripping and Going places (translocation)

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85
Q

the lower the Km, the _____ the affinity

86
Q

this type of inhibitor resembles substrate

A

competitive inhibitor

87
Q

this type of inhibitor can be overcome by increase concentration of substrate

A

competitive inhibitor

88
Q

this type of inhibitor binds to the active site

A

competitive inhibitor

89
Q

competitive inhibitors have this effect on Vmax

90
Q

non0competitive inhibitors have this effect on Vmax

91
Q

competitive inhibitors have this effect on Km

92
Q

Noncompetitive inhibitors have this effect on Km

93
Q

enzyme regulation methods:

alter this for increased or decreased synthesis or destricution effects

A

enzyme concentrations

94
Q

enzyme regulation methods: phosphorylation effects

A

covalent modification

95
Q

enzyme regulation methods:

proteolytic modification effects

96
Q

enzyme regulation methods:

allosteric regulation effects

A

feedback inhibition

97
Q

enzyme regulation methods:

steroid hormones effects

A

transcriptional regulation

98
Q

Give the Cell cycle synthesis phases and what they stand for

A 
M (mitosis: prophase-metaphase-anaphase-telophase)
G1 (growth)
S (synthesis of DNA)
G2 (growth)
Go (quiescent G1 phase)
99
Q

these 2 phases are of variable duration

100
Q

this is usually the shortest phase

101
Q

Most cells are in this phase

102
Q

rapidly dividing cells have a shorter ____ phase

103
Q

this is the site of synthesis of secretory (exported proteins and of N-linked oligosaccharide addition to many proteins

A

Rough endoplasmic reticulum (RER)

104
Q

Mucus-secreting goblet cells of the small intestine and antibody-secreting plasma cells are rich here

105
Q

this is the site of steroid synthesis and detoxification of drugs and poisons

A

smooth endoplasmic reticulum (SER)

106
Q

Liver hepatocytes and steroid hormone-producing cells of the adrenal cortex are rich in _____

107
Q

Functions of Golgi apparatus

A

1) distribution center of proteins and lipids from ER to the plasma membrane, lysosomes, and secretory vesicles
2) modifies N-oligosaccharides on asparagine
3) Adds O-oligosaccharides to serine and threonine residues
4) Proteoglycan assembly from proteoglycan core proteins
5) Sulfation of sugars in proteoglycans and of selected tyrosine on proteins
6) Addition of mannose-6 phosphate to specific lysosomal proteins, which targets the protein to the lysosome.

108
Q

I cell disease is caused by the failure of the addition of _________ to lysosome proteins, causing thse enzymes to be secreted outside the cell inside of being targeted to the lysosome. Characterized by coarse facial features and restricted joint movement.

A

mannose-6-phosphate

109
Q

This is a cylindrical sx 24 nm in diameter and of variable lenght. A helical array of polymerized dimers of alpha and Beta tubulin (13 per circumference). Each dimer has 2 GTP bound. Incorporated into flagella, cilia, mitotic spindles. Grows slowly, collapses quickly.

A

microtubules

110
Q

this cell sxs are involved in slow axoplasmic transport in neurons

A

microtubules

111
Q

name 5 drugs that act on microtubules

A

1) mebendazole/thiabendazole (antihelminthic)
2) taxol (anti Br CA
3) Griseofulvin (antifungal)
4) Vincristine/Vinblastine (anti-cancer)
5) Colchicine (anti gout

112
Q

This syndrome is due to a microtubule polymerization defect resulting in decreased phagocytosis

A

Chediak-Higashi syndrome

113
Q

this cell sx has 9 + 2 arrangement of microtubules

114
Q

In cilia, this is an ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets

115
Q

this syndrome is due to a dynein arm defect, resulting in immotile cilia

A

Kartagener’s syndrome

116
Q

dynein is

A

retrograde

117
Q

kinesin is

A

anterograde

118
Q

what are the 2 major components of plasma membranes

A

cholesterol (-50%)
phospholipids (-50%)

there are also sphingolipids, glycolipids, and proteins.

119
Q

High cholesterol or long saturated fatty acid content results in this

A

increase melting temp.

120
Q

this side of the membrane contains glycosylated lipids or proteins

A

noncytoplasmic side

121
Q

T or F. The plasma membrane is an asymmetric, fluid bilater

122
Q

This is a major component of RBC membranes, of myelin, of bile, and of surfactant. It is also used in the esterification of cholesteral.

A

Phosphatidylcholine

123
Q

specific phosphatidylcholine used in esterification of chelesterol

A

LCAT is lecithin-cholesterol acyltransferase

124
Q

specific phosphatidylcholine used in surfactant

A

DPPC= dipalmitoyl phosphatidylcholine

125
Q

This is located in the plasma membrane w/ ATP site on the cytoplasmic side.

A

Na+K+ATPase (sodium pump)

126
Q

For each ATP consumed, ___ Na+ go out and __ K+ come in.

127
Q

During each cycle of the sodium pump this occurs

A

phosphorylation

128
Q

This inhibits by blinding to K+ site.

129
Q

These also inhibit the Na+K+ATPase causing increased cardiac contractility

A

cardiac glycosides (digoxin, digitoxin)

130
Q

This is the most abundant protein in the human body. It fxs to organize and strengthen extracellular matrix.

131
Q

this type of collagen is 90% of collagen. It makes up BONE, tendon, skin, dentin, fascia, cornia, late wound repair

A

Type I

mneu: B Cool, Read Books
type I: bONE

132
Q

this type of collagen makes up CARTILAGE (including hyaline), vitreous body, nucleus pulposis

A

Type II

mneu: B Cool, Read Books
type II: carTWOlage

133
Q

this type of collagen makes up skin, blood vessels, uterus, fetal tissue, granulation tissue

A

Type III (reticulin)

mneu: B Cool, Read Books

134
Q

this type of collagen makes up basement membrane or basal lamina

A

Type IV

mneu: B Cool, Read Books
Type IV: under the floor (basement membrane

135
Q

This type of cartilage makes up the epiphyseal plate

136
Q

collagen alpha chains are called

A

preprocollagen

137
Q

preprocollagen is translated on this

138
Q

Inside fibroblast, collagen alpha chains or (preprocollagen) is usually this type of polypeptide

A

Gly-XY (X & Y are proline, hydroxyproline or hydroxylysine)

139
Q

inside the the ER in fibroblasts hydroxylation of specific proline and lysine residues occurs. Hydroxylation requires this vitamen

140
Q

Inside fibroblasts the golgi glycosylates the pro alpha chain lysine residues and formation of _______

A

procollagen (triple helix of 3 collagen chains)

141
Q

these molecules are then exocytosed into into the extracellular space

A

procollagen

142
Q

outside fibroblasts, procollagen peptidases cleave terminal regions of procollagen, transforming procollagen into insoluble ______

A

tropocollagen

143
Q

Many staggered tropocollagen molecules are reinforced by covalent lysine-hydroxylysine cross linkage (by lysyl oxidase) to make

A

collagen fibrils

144
Q

this syndrome results in faulty collagen synthesis causing:

1) hyperextensible skin
2) tendency to bleed (easy bruising)
3) hypermobile joints

A

ehlers-danlos syndrome

145
Q

Ehlers-Danlos syndrome is associated with this problem

A

berry aneurysms

146
Q

This dz is a primarily autosomal-dominant d/o caused by a variety of gene defects resulting in abnormal collagen synthesis. It is characterized by :

1) multiple fractures occuring with minimal trauma (brittle bone dz), which may occur during the birth process
2) Blue sclerae due to the translucency of the connective tissue over the choroid
3) hearing loss (abnormal middle ear bones)
4) Dental imperfections due to lack of dentition

A

osteogenesis imperfecta

147
Q

What can osteogenesis be confused with

A

child abuse

148
Q

what is the incidence of OI type I

149
Q

what is the incidence of OI type II

A

0 - death in utero

150
Q

Given the immunohistochemical stain give the cell type it stains for:
Vimentin

A

Connective tissue

151
Q

Given the immunohistochemical stain give the cell type it stains for:
Desmin

152
Q

Given the immunohistochemical stain give the cell type it stains for:
Cytokeratin

A

epithelial cells

153
Q

Glial fibrillary acid proteins (GFAP)

154
Q

Neurofilaments

155
Q

Give the site of metabolism: Fatty acid oxidation (B-oxidation)

A

mitochondria

156
Q

Give the site of metabolism: acetyl-CoA production

A

mitochondria

157
Q

Give the site of metabolism: Krebs cycle

A

mitochondria

158
Q

Give the site of metabolism: glycolysis

159
Q

Give the site of metabolism: fatty acid synthesis

160
Q

Give the site of metabolism: HMP shunt

161
Q

Give the site of metabolism: protein synthesis (RER)

162
Q

Give the site of metabolism: steroid synthesis (SER)

163
Q

Give the site of metabolism: gluconeogenesis

A

both cytoplasm and mitochondria

164
Q

Give the site of metabolism: urea cycle

A

both cytoplasm and mitochondria

165
Q

Give the site of metabolism: heme synthesis

A

both cytoplasm and mitochondria

166
Q

give the enzyme deficiency that would result in MILD galactosemia

A

galactokinase

167
Q

give the enzyme deficiency that would result in SEVERE galactosemia

A

galactose-1-phosphate uridyltransferase

168
Q

give the enzyme deficiency that would result in Von Gierke’s

A

glucose-6-phosphatase

169
Q

give the enzyme deficiency that would result in essential fructosuria

A

fructokinase

170
Q

give the enzyme deficiency that would result in fructose intolerance

A

aldolase B

171
Q

This is an adenine base + ribose + 3 phosphoryls. 2 phosphoanhydride bonds, 7 kcal/mol each

172
Q

aerobic metabolism of glucose produces this manny ATP via the malate shuttle and this many ATP via G3P shuttle

173
Q

Anaerobic glycolysis produces this many ATP per glucose molecule

174
Q

How is ATP hydrolysis used

A

it is coupled to energetically unfavorable rxns

175
Q

Give the activated carrier for each molecule:

ATP

A

phosphoryl

176
Q

Give the activated carrier for each molecule: NADH, NADPH, FADH2

177
Q

Give the activated carrier for each molecule: Coenzyme A, lipoamide

178
Q

Give the activated carrier for each molecule: biotin

179
Q

Give the activated carrier for each molecule: tetrahydrofolates

A

1-carbon units

180
Q

Give the activated carrier for each molecule: SAM

A

CH3 groups

181
Q

Give the activated carrier for each molecule: TPP

182
Q

Give the activated carrier for each molecule: UDP-glucose

183
Q

Give the activated carrier for each molecule: CDP-choline

184
Q

ATP + methionine –>

185
Q

What does SAM do?

A

SAM transfers methyl units to a wide variety of acceptors (e.g., synthesis of phosphocreatine, a high-energy phosphate active in muscle ATP production).

mneu: SAM the methyl donor man

186
Q

Regeneration of methionine (and thus SAM) is dependent on this vitamen

187
Q

give the signal molecule given its precursor: ATP ->

A

cAMP via adenylate cyclase

188
Q

give the signal molecule given its precursor: GTP ->

A

cGMP via guanylate cyclase

189
Q

give the signal molecule given its precursor: Glutamate ->

A

GABA via glutamate decarboxylase (requires vitamen B6

190
Q

give the signal molecule given its precursor: choline->

A

ACH via choline acetyltransferase (ChAT)

191
Q

give the signal molecule given its precursor: arachidonate->

A

prostaglandins, thromboxanes, leukotrienes via cyclooxygenase/ lipoxygenase

192
Q

give the signal molecule given its precursor: fructose-6-P->

A

fructose 1,6-bis-P via phosphofructokinase (PFK), the rate-limiting enzyme of glycolysis

193
Q

give the signal molecule given its precursor: 1,3BPG->

A

2,3-BPG via bisphosphoglycerate mutase

194
Q

what are the 2 universal electron acceptors

A

Nicotinamides (NAD+,NADP+) and flavin nucleotides (FAD+)

195
Q

Describe 1st step of B-oxidation of very long chain FA in Peroxisomes?

A

1st step of of B-oxidation is catalized by an FAD containing oxidase. e- are transfered from FADH2 to O2 which is then reduced to H2O2

Takes place in peroxisome because H2O2 is produced

196
Q

What are similarities & differences of mitochondrial vs peroxisomal B-oxidation?

A

Both generate FADH2 & NADH but

Peroxisomal is less efficient because FADH can’t get through peroxisomal membrane (must be oxidized by O2)

197
Q

Why do peroxysomal B-oxidation?

A

very long chain FA cannot cross mit membrane, must be broken up by peroxysomes

198
Q

Describe oxydation of phytanic acid?

A

a peroxysomal alpha hydroxylase oxidizes the alpha carbon so that B oxidation can occur.

199
Q

Refsum’s disease

A

alpha oxidase enzyme is defective so we cannot break down phytanic acid

200
Q

w-oxidation of FA

A

converts FA to dicarboxylic acids. Results in DC urea. Which is diagnostic for problem w/ B oxidation

201
Q

4 steps of B-oxidation

A

1) Oxidation (ACoA dehyd)
2) Hydration (enol CoA hyd)
3) Oxidation(B hydroxy CoA hyd)
4) Cleavage (B keto thiolase)

202
Q

Metabolism of Monosaturated Fats

A

2-3 enol-CoA isomerase - converts cis bond to trans

203
Q

Metabolism of Polyunsaturated Fats

A

2-3 enol-CoA isomerase - converts cis bond to trans

2-4 dienol Co A reductase – reduces one of the double bonds

204
Q

Propynyl Co A pathway

A

Propionyl CoA to Succinyl CoA. 1st step involves Propionyl CoA carboxylase (ABC enzyme) conversionof Propionyl CoA to methmylmalonyl CoA. Last step involves methyl-Malonyl CoA mutase conversion of Methylmalonyl CoA to Succinyl CoA. This last enzyme requires B12 therefore build up of Methylmalonyl CoA is diagnostic for B12 deficiency.

205
Q

ABC enzymes

A

ABC
Pyruvate carboxylase -
Acetyl CoA carboxylase -
Propionyl CoA carboxylase -

206
Q

MCAD deficiency

A

B oxidation in liver tissue in order for gluconeogenesis – if can’t do B-oxidation – hypoglycemic shock;
Feed child, replenished glycogen stores, in night using glycogen stores, next morning feed – child never in hard glucagon world. Never know about deficiency. Using liver glycogen always. When glycogen stores don’t get built up child needs to do gluconeogenis need to do B oxidation – usually dies in middle of night.

207
Q

3 ketone bodies:

A

1) Acetoacetate can covert to:
2) Acetone (volitile)
3) D-B Hydroxybutyrate (more stable)

208
Q

Why are ketone bodies made in liver cells only?

A

HMG Co A synthase –makes ketone bodies and found only in liver mitochondria

209
Q

Why are ketone bodies broken down in tissues other than the liver

A

B-ketoacyl- CoA transferase is found in mitochondria outside liver -allows extrahepatic tissues to break ketone bodies down

210
Q

Fuel for Brain

1) 24 hours
2) day 2-7
3) After 1 week

A

1) glycogen
2) protein (mostly glucose from gluconeogenesis but some ketone bodies)
3) Fat & small amount of protein-mostly ketone bodies but some glucose from gluconeogenesis

Step 1 Complete (29 decks)

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