Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Biochemistry 1/2, First Aid for the USMLE Step 1 > Flashcards

Biochemistry 1/2, First Aid for the USMLE Step 1 Flashcards

1
Q

DNA charge

A

Negative

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

Histone charge

A

Positive

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

Negatively charged DNA loops ___ around positively charged histone octamer to form nucleosome “___.”

A

Twice; beads on a string

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

Histones are rich in the amino acids ___

A

Lysine and arginine

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

___ binds to the nucleosome and to “linker DNA,” thereby stabilizing the chromatin fiber

A

H1

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

DNA and histone synthesis occur during ___ phase of the cell cycle

A

S phase

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

Condensed chromatin that appears darker on EM

A

Heterochromatin [Think HeteroChromatin, Highly Condensed]

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

Less condensed chromatin that appears lighter on EM

A

Euchromatin

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

Transcriptionally inactive chromatin, sterically inaccessible

A

Heterochromatin

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

Transcriptionally active, sterically accessible

A

Euchromatin

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

Inactive X chromosomes

A

Barr bodies

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

Heterochromatin vs Euchromatin: Barr bodies

A

Heterochromatin

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

Template strand ___ and ___ are methylated in DNA replication, which allows mismatch repair enzymes to distinguish between old and new strands in prokaryotes

A

Cytosine, adenine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What methylation processes make DNA mute or repress DNA transcription

A

DNA methylation; histone methylation (repress or activate DNA transcription)

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

Relaxes DNA coiling, allowing for transcription

A

Histone acetylation [Think Acetylation = Active]

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

Purines

A

Adenine, Guanine [Think PURe As Gold]

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

Pyrimidines

A

Cytosine, Uracil, Thymine [Think CUT the PY]

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

Purines vs Pyrimidines: 2 rings

A

Purines [Pyrimidines = PYRamids can stand alone = 1 ring]

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

Which pyrimidine has a methyl

A

Thymine [ Think THYmine has a meTHYl]

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

What makes uracil

A

Deamination of cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Uracil is found in

A

RNA

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

Thymine is found in

A

DNA

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

Base pair with 2 hydrogen bonds

A

A-T [Think 2 AToms of hydrogen]

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

Base pair with a higher melting point

A

G-C (3 H bonds)

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

Amino acids necessary for purine synthesis

A

Glycine, Aspartate, Glutamate [GAG]

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

Amino acid necessary for pyrimidine synthesis

A

Aspartate

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

A nucleoSide is composed of

A

Base + Sugar (ribose or deoxyribose)

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

A nucleoTide is made of

A

Base + Sugar + phosphaTe; linked by 3’-5’ phosphodiester bond

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

De novo purine synthesis

A

1) Sugar + phosphate (PRPP) 2) Add base

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

De novo pyrimidine synthesis

A

1) Temporary base (orotic acid) 2) Add sugar + phosphate (PRPP) 3) Modify base

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

Which are synthesised first, ribonucleotides vs deoxyribonucleotides

A

Ribonucleotides are synthesized first and are converted to deoxyribonucleotides by ribonucleotide reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Carbamoyl phosphate is involved in what 2 metabolic pathways

A

1) De novo pyrimidine synthesis 2) Urea cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Inhibits dihydroorotate dehydrogenase (pyrimidine base production)

A

Leflunomide [dihydrOO leflOO]

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

Inhibit IMP dehydrogenase (purine base production)

A

Mycophenolate mofetil and ribavirin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Inhibits ribonucleotide reductase (pyrimidine base production)

A

Hydroxyurea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Inhibits de novo purine synthesis

A

6-MP and its prodrug azathioprine

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

Inhibits thymidilate synthase (dUMP>dTMP; pyrimidine base synthesis)

A

5-FU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Inhibits DHFR

A

1) MTX (humans) 2) TMP (bacteria) 3) Pyrimethamine (protozoa)

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

Inhibited by Allopurinol and Febuxostat in purine salvage pathway

A

Xanthine oxidase

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

Xanthine oxidase catalyses what 2 reactions in the purine salvage pathway

A

1) Hypoxanthine > xanthine 2) Xanthine > uric acid

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

Promotes excretion of uric acid in urine

A

Probenecid

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

Causes excess ATP and dATP > feedback inhibition of ribonucleotide reductase > prevents DNA synthesis > decreases lymphocyte count

A

Adenosine deaminase deficiency (one of the major causes of SCID)

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

Defective purine salvage due to absent HGPRT

A

Lesch-Nyhan syndrome

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

HGPRT catalyzes

A

1) Hypoxanthine to IMP 2) Guanine to GMP

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

Treatment of choice for Lesch-Nyhan

A

Allopurinol (2nd line: Febuxostat)

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

Genetic code feature: Each codon specifies only 1 amino acid

A

Unambiguous

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

Genetic code feature: Most amino acids are coded by multiple codons

A

Degenerate/ redundant

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

Genetic code feature: Read from a fixed starting point as a continuous sequence of bases

A

Commaless, nonoverlapping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Genetic code feature: Conserved throughout evolution

A

Universal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Amino acids encoded by only 1 codon each and are exceptions to degenerate/redundance feature of genetic code

A

1) Methionine 2) Tryptophan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Methionine, codon

A

AUG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Tryptophan, codon

A

UGG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Genetic code is universal except

A

In mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Y-shaped region along DNA template where leading and lagging strands are synthesized

A

Replication fork

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Unwinds DNA template at replication fork

A

Helicase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Prevent strands from reannealing

A

Single-stranded binding proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Create a single- or double-stranded break in the helix to add or remove supercoils

A

DNA topoisomerases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV

A

Fluoroquinolones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Prokaryotic DNA polymerase that elongates leading strand by adding deoxynucleotides to the 3_ end; has 5>3 synthesis and proofreads with 3>5 exonuclease

A

DNA polymerase III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Prokaryotic DNA polymerase that degrades RNA primer and replaces it with DNA

A

DNA polymerase I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Catalyzes the formation of a phosphodiester bond within a strand of double-stranded DNA (i.e., joins Okazaki fragments); SEALS

A

DNA ligase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

An RNA-dependent DNA polymerase that adds DNA to 3_ ends of chromosomes to avoid loss of genetic material with every duplication

A

Telomerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

T/F Telomerase is found in both prokaryotes and eukaryotes

A

F, eukaryotes only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Severity of DNA damage from least to greatest

A

Silent, missense, nonsense, frameshift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Point mutations

A

1) Silent 2) Missense 3) Nonsense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Point mutation in which purine is replaced by purine or pyrimidine by another pyrimidine

A

Transition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Point mutation in which purine is replaced by a pyrimidine or pyrimidine by a purine

A

Transversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Nucleotide substitution but codes for same (synonymous) amino acid

A

Silent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Nucleotide substitution resulting in changed amino acid

A

Missense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Nucleotide substitution resulting in early stop codon

A

Nonsense [Think STOP the NONSENSE]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Deletion or insertion of a number of nucleotides not divisible by 3, resulting in misreading of all nucleotides downstream, usually resulting in a truncated, nonfunctional protein

A

Frameshift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Type of mutation in Duchenne muscular dystrophy

A

Frameshift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Base change in silent mutation is usually at which position

A

3rd position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What do you call the base change in 3rd position of codon

A

tRNA wobble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

A missense is called “conservative” if

A

The new amino acid is similar in chemical structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Sickle cell disease is what type of mutation

A

Missense (glutamic acid>val)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Single strand DNA repair: Specific endonucleases release the oligonucleotides containing damaged bases; DNA polymerase and ligase fill and reseal the gap, respectively

A

Nucleotide excision repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Nucleotide excision repair occurs in what phase of the cell cycle

A

G1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Single strand DNA repair: Important in repair of spontaneous/toxic deamination; occurs throughout the cell cycle

A

Base excision repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What DNA repair mechanism is defective in xeroderma pigmentosum, which prevents repair of pyrimidine dimers because of ultraviolet light exposure

A

Nucleotide excision repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What single strand DNA repair mechanism is defective in hereditary nonpolyposis colorectal cancer (HNPCC)

A

Mismatch repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Mismatch repair occurs predominantly in which phase of the cell cycle

A

G2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Double strand DNA repair mechanism: Some DNA may be lost; mutated in ataxia telangiectasia and Fanconi anemia

A

Nonhomologous end joining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

DNA and RNA are both synthesised in what direction

A

5’>3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

The ___ of the incoming nucleotide bears the triphosphate (energy source for bond)

A

5_ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Protein synthesis is ___ to ___

A

N-terminus, C-terminus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

mRNA is read from what end to what end

A

5’ to 3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Target of the 3_ hydroxyl attack

A

Triphosphate bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Drugs blocking DNA replication often have modified ___, preventing addition of the next nucleotide (“chain termination”)

A

3_ OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

mRNA start codon

A

AUG (rarely GUG) [Think inAUGurates protein synthesis]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

AUG in eukaryotes codes for what amino acid

A

Methionine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

AUG in prokaryotes codes for

A

N-formylmethionine (fMet)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Function of fMet

A

Stimulates neutrophil chemotaxis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

mRNA stop codons

A

UGA, UAA, UAG [Think U Go Away, U Are Away, U Are Gone]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Site in the gene where RNA polymerase II and multiple other transcription factors bind to DNA upstream from gene locus

A

Promoter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

AT-rich upstream sequence with TATA and CAAT boxes

A

Promoter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Stretch of DNA that alters gene expression by binding transcription factors

A

Enhancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Site in the gene where negative regulators (repressors) bind

A

Silencer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

RNA polymerase: Makes rRNA

A

RNA polymerase I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

RNA polymerase: Makes mRNA

A

RNA polymerase II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

RNA polymerase: Makes tRNA

A

RNA polymerase III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Most numerous RNA

A

rRNA [Rampant]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Largest RNA

A

mRNA [Massive]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Smalles RNA

A

tRNA [Tiny]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

RNA polymerase: Opens DNA at promoter site

A

RNA polymerase II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

RNA polymerase II is inhibited by what substance, which causes severe hepatotoxicty if ingested

A

alpha-amanitin, found in Amanita phalloides (death cap mushrooms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Drug that inhibits RNA polymerase in prokaryotes

A

Rifampin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Drug that inhibits RNA polymerase in both prokaryotes and eukaryotes

A

Actinomycin D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

How many RNA polymerases are then in prokaryotes?

A

Only 1 (makes all 3 kinds of RNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Initial RNA transcript in eukaryotes that is subsequently modified and becomes mRNA

A

Heterogenous nuclear RNA (hnRNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

3 processes that occur in the nucleus following transcription

A

1) Capping of 5’ end (7-methylguanosine cap) 2) Polyadenylation of 3’ end 3) Splicing out of introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

Capped, tailed, and spliced RNA transcript is called

A

mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Where does transcription occur

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Where does translation occur

A

Cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

mRNA quality control occurs at

A

P-bodies in cytoplasm (also the site of mRNA storage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

Polyadenylation signal

A

AAUAA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

Primary transcript combines with ___ and other proteins to form spliceosome

A

Small nuclear ribonucleoproteins (snRNPs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Antibodies to snRNPs

A

Anti-Smith antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

Introns vs. exons: Contain the actual genetic information coding for protein

A

Exons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

Introns vs. exons: Intervening noncoding segments of DNA

A

Introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Introns vs. exons: Stay in the nucleus

A

Introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

RNA that assumes a cloverleaf form

A

tRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

At which end of the tRNA is the anticodon found

A

Opposite the 3’ aminoacyl end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

Amino acid is covalently bound to which end of tRNA

A

3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

This enzyme scrutinizes amino acid before and after it binds to tRNA, and if incorrect, bod is hydrolyzed

A

Aminoacyl-tRNA synthetase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

T/F Accurate base pairing is usually required only in the first 2 nucleotide positions of an mRNA codon, so codons differing in the 3rd “wobble” position may code for the same tRNA/amino acid

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

Protein synthesis is initiated by

A

GTP hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

Ribosome site that receives incoming aminoacyl-tRNA

A

A site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Ribosome site that accommodates the growing peptide

A

P site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

Ribosome site that holds empty tRNA as it exits

A

E site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

At which ribosome subunit are the A, P, and E sites found

A

60S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

___ catalyzes peptide bond formation and transfers growing polypeptide to amino acid in A site

A

rRNA (“ribozyme”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Posttranslational modification of protein: Removal of N- or C-terminal propeptides from zymogen to generate mature protein (e.g., trypsinogen to trypsin)

A

Trimming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

Posttranslational modification of protein: Phosphorylation, glycosylation, hydroxylation, methylation, acetylation, and ubiquitination

A

Covalent alterations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Intracellular protein involved in facilitating and/or maintaining protein folding, e.g. heat shock proteins

A

Chaperone protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Shortest phase of cell cycle

A

M phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

Constitutive regulator of the cell cycle

A

CDKs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

Regulatory proteins that control cell cycle events; phase specific; activate CDKs

A

Cyclins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

Phosphorylate other proteins to coordinate cell cycle progression; must be activated and inactivated at appropriate times for cell cycle to progress

A

Cyclin-CDK complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

Inhibit G1-to-S progression, the mutation of which result in unrestrained cell division

A

Tumor suppressors, p53 and Rb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

Phase of the cell cycle where DNA synthesis occurs

A

S phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

Phases of the cell cycle

A

G0 > G1 > S > G2 > M > G0 or G1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Cells that remain in G0, regenerate from stem cells

A

Permanent cells (neurons, skeletal and cardiac muscle, RBCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

Cells that enter G1 from G0 when stimulated

A

Stable (quiescent) (hepatocytes, lymphocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

Cells that never go to G0, divide rapidly with a short G1. Most affected by chemotherapy.

A

Labile cells (bone marrow, gut epithelium, skin, hair follicles, germ cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

Site of synthesis of secretory (exported) proteins and of N-linked oligosaccharide addition to many proteins

A

RER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

Site of synthesis of cytosolic and organellar proteins

A

Free ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

Site of steroid synthesis and detoxification of drugs and poisons

A

SER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

SER is rich in

A

1) Hepatocytes 2) Steroid hormone- producing cells of the adrenal cortex 3) Gonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

Distribution center for proteins and lipids from the ER to the vesicles and plasma membrane

A

Golgi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

Abundant, cytosolic ribonucleoprotein that traffics proteins from the ribosome to the RER; the absence or dysfunction of which causes protein accumulation in the cytosol

A

Signal recognition particle (SRP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

Vesicular trafficking protein: Golgi > Golgi (retrograde); cis-Golgi > ER

A

COPI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

Vesicular trafficking protein: ER > cis-Golgi (anterograde)

A

COPII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

Trans-Golgi > lysosomes; plasma membrane > endosomes (receptor- mediated endocytosis)

A

Clathrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

Membrane-enclosed organelle involved in catabolism of very-long-chain fatty acids, branched-chain fatty acids, and amino acids

A

Peroxisome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

Barrel-shaped protein complex that degrades damaged or ubiquitin-tagged proteins

A

Proteasome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

Cell filament: Muscle contraction, cytokinesis

A

Microfilaments, e.g. actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

Cell filament: Maintain cell structure

A

Intermediate filaments, e.g. Vimentin, desmin, cytokeratin, lamins, glial fibrillary acid proteins (GFAP), neurofilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

Cell filament: Movement, cell division

A

Microtubules, e.g. Cilia, flagella, mitotic spindle, axonal trafficking, centrioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

Immunohistochemical stain: Connective tissue

A

Vimentin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

Immunohistochemical stain: Muscle

A

Desmin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

Immunohistochemical stain: Epithelial cells

A

Cytokeratin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

Immunohistochemical stain: Neuroglia

A

GFAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

Immunohistochemical stain: Neurons

A

Neurofilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

Cylindrical structure composed of a helical array of polymerized heterodimers of _- and _-tubulin

A

Microtubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

Drugs that act on microtubules

A

[Microtubules Get Constructed Very Poorly] 1) Mebendazole (antihelminthic) 2) Griseofulvin (anti fungal) 3) Colchicine (anti gout) 4) Vincristine/Vinblastine (anticancer) 5) Paclitaxel (anticancer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

9 + 2 arrangement of microtubule doublets

A

Cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

Immotile cilia due to a dynein arm defect; immotility in both men and women (immotile sperm and dysfunctional fallopian tube cilia)

A

Kartagener syndrome/primary ciliary dyskinesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

Inhibits Na-K ATPase pump by binding to K+ site

A

Ouabain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

Drugs that directly inhibit the Na+-K+ ATPase, which leads to indirect inhibition of Na+/Ca2+ exchange > increase in [Ca2+]i > increase in cardiac contractility

A

Cardiac glycosides (digoxin and digitoxin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
171
Q

Most abundant protein in the human body

A

Collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
172
Q

MC type of collagen (90%)

A

Type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
173
Q

Synthesizes type I collagen in bone

A

Osteoblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
174
Q

Sites of type I collagen

A

Bone (made by osteoblasts), Skin, Tendon, dentin, fascia, cornea, late wound repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
175
Q

Sites of type II collagen

A

Cartilage (including hyaline), vitreous body, nucleus pulposus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
176
Q

Sites of type III collagen

A

Reticulin—skin, blood vessels, uterus, fetal tissue, granulation tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
177
Q

Sites of type IV collagen

A

Basement membrane, basal lamina, lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
178
Q

Collagen type: Decreased production in osteogenesis imperfecta type I

A

I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
179
Q

Collagen type: Deficient in the uncommon, vascular

type of Ehlers-Danlos syndrome

A

III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
180
Q

Collagen type: Defective in Alport syndrome

A

IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
181
Q

Collagen type: Targeted by autoantibodies in Goodpasture syndrome

A

IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
182
Q

In what cells is collagen synthesized

A

Fibroblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
183
Q

In what organelle is collagen synthesized

A

RER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
184
Q

Steps in collagen synthesis that take place in fibroblasts

A

1) Synthesis (preprocollagen) 2) Hydroxylation of proline and lysine residues 3) Glycosylation and formation of procollagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
185
Q

Steps in collagen synthesis that take place outside fibroblasts

A

1) Proteolytic processing (formation of tropocollagen by cleavage of disulfide-rich regions of procollagen) 2) Cross-linking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
186
Q

Structure of preprocollagen (collagen alpha chains)

A

Gly-X-Y (Gly is glycine; X and Y are proline or lysine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
187
Q

Best reflects collagen synthesis

A

Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
188
Q

Collagen is 1/3 ___ (amino acid)

A

Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
189
Q

What step in collagen synthesis requires Vitamin C?

A

Hydroxylation of specific proline and lysine residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
190
Q

Problems forming triple helix of 3 collagen _ chains (glycosylation and formation of procollagen)

A

Osteogenesis imperfecta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
191
Q

Problems with collagen cross-linking lead to

A

1) Ehler-Danlos 2) Menkes disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
192
Q

AKA Brittle bone disease

A

Osteogenesis imperfecta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
193
Q

Why is there hearing loss in osteogenesis imperfecta

A

Abnormal ossicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
194
Q

Faulty collagen synthesis causing hyperextensible skin, tendency to bleed (easy bruising), and hypermobile joints

A

Ehlers-Danlos syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
195
Q

MC type of Ehlers-Danlos syndrome

A

Hypermobility type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
196
Q

Classical type of Ehlers-Danlos is due to mutation of what collagen type

A

V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
197
Q

Vascular type (vascular and organ rupture) of Ehlers-Danlos is due to deficiency of

A

Type III collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
198
Q

X-linked recessive connective tissue disease caused by impaired copper absorption and transport due to defective ATP7A

A

Menkes disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
199
Q

Menkes disease is associated with decreased activity of what enzyme

A

Lysyl oxidase (copper is a necessary cofactor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
200
Q

Elastin is rich in what amino acids

A

1) Proline 2) Glycine 3) Lysine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
201
Q

Where does elastin cross-linking take place

A

Extracellularly

202
Q

Where is elastin found

A

Skin, lungs, large arteries, elastic ligaments, vocal cords, ligamenta flava (connect vertebrae)

203
Q

Elastin is broken down by elastase, which is normally inhibited by

A

_1-antitrypsin

204
Q

A glycoprotein that forms a sheath around elastin

A

Fibrillin (defective in Marfan syndrome)

205
Q

Wrinkles of aging are due to decreased production of what proteins

A

Collagen and elastin

206
Q

Steps in PCR

A

1) Denaturation 2) Annealing 3) Elongation

207
Q

Denaturating agent in PCR that generates 2 separate strands

A

Heating

208
Q

Anneal to a specific sequence on each strand to be amplified during cooling

A

DNA primers

209
Q

Replicates the DNA sequence following each primer

A

Heat-stable DNA polymerase

210
Q

Used for size separation of PCR products (smaller molecules travel further) and compared against DNA ladder

A

Agarose gel electrophoresis

211
Q

Blotting procedures and corresponding biomolecule electrophoresed

A

[SNoW DRoP] Southern: DNA, Northern: RNA, Western: Protein

212
Q

Blotting procedure used as confirmatory test for HIV after a (+) ELISA

A

Western blot

213
Q

Blotting procedure used to identify DNA-binding proteins such as transcription factors

A

Southwestern blot

214
Q

Used to detect the presence of either a specific antigen or a specific antibody in a patient’s blood sample

A

ELISA

215
Q

Direct vs Indirect ELISA: Uses a test antibody to see if a specific antigen is present

A

Direct

216
Q

Direct vs Indirect ELISA: Uses either a test antigen or antibody to see if a specific antibody or antigen, respectively, is present

A

Indirect

217
Q

Karyotyping makes use of chromosomes at what phase of the cell cycle

A

Metaphase

218
Q

Karyotyping can be performed on what samples

A

Blood, bone marrow, amniotic fluid, or placental tissue

219
Q

When is FISH used instead of karyotyping

A

When deletion is too small to be visualized by karyotype

220
Q

Fluorescence vs no fluorescence: Gene is absent/deleted

A

No fluorescence

221
Q

Production of a recombinant DNA molecule that is self-perpetuating

A

Cloning

222
Q

RNA used in cloning

A

mRNA

223
Q

Cloned DNA (cDNA) lacks what part of the gene

A

Introns

224
Q

Can be used to study a gene whose deletion causes embryonic death

A

Cre-lox system

225
Q

Both alleles contribute to the phenotype of the heterozygote, e.g. Blood groups A, B, AB

A

Codominance

226
Q

Phenotype varies among individuals with same genotype, e.g. more severe in some and less severe in others

A

Variable expressivity

227
Q

Not all individuals with a mutant genotype show the mutant phenotype, e.g. BRCA1 mutations do not always result in breast or ovarian CA

A

Incomplete penetrance

228
Q

One gene contributes to multiple phenotypic effects

A

Pleiotropy

229
Q

Increased severity or earlier onset of disease in succeeding generations

A

Anticipation

230
Q

A mosaicism and is due to mutation affecting G-protein signaling

A

McCune-Albright syndrome

231
Q

2 syndromes that are both due to mutation or deletion of genes on chromosome 15

A

1) Prader-Willi 2) Angelman

232
Q

Maternal imprinting: gene from mom is normally silent and Paternal gene is deleted/ mutated

A

Prader-Willi

233
Q

Paternal imprinting: gene from dad is normally silent and Maternal gene is deleted/mutated

A

Angelman

234
Q

Mode of inheritance: Often due to defects in structural genes. Many generations, both male and female, affected.

A

Autosomal dominant

235
Q

to diagnosis

A

Autosomal dominant

236
Q

Mode of inheritance: Often due to enzyme deficiencies. Usually seen in only 1 generation.

A

Autosomal recessive

237
Q

T/F Autosomal recessive diseases are commonly more severe than dominant disorders

A

T

238
Q

Mode of inheritance: Increased risk in consanguineous families

A

Autosomal recessive

239
Q

Mode of inheritance: Sons of heterozygous mothers have a 50% chance of being affected. No male-to-male transmission. Skips generations.

A

X-linked recessive

240
Q

Mode of inheritance: Transmitted through both parents. Mothers transmit to 50% of daughters and sons; fathers transmit to all daughters but no sons.

A

X-linked dominant

241
Q

Disease with X-linked dominant inheritance

A

Hypophosphatemic rickets, formerly known as vitamin D-resistant rickets

242
Q

Mode of inheritance: Transmitted only through the mother. All offspring of affected females may show signs of disease

A

Mitochondrial inheritance

243
Q

Muscle biopsy of mitochondrial myopathies often shows

A

Ragged red fibers

244
Q

Autosomal dominant diseases

A

1) Autosomal dominant polycystic kidney disease (ADPKD) 2) FAP 3) Familial hypercholesterolemia 4) Hereditary hemorrhagic telangiectasia 5) Hereditary spherocytosis 6) Huntington disease 7) Li-Fraumeni syndrome 8) Marfan 9) MEN 10) NF 1 (von Recklinghausen) and 2 11) Tuberous sclerosis 12) von Hippel-Lindau

245
Q

Colon becomes covered with adenomatous polyps after puberty, which may progress to colon cancer unless colon is resected

A

FAP

246
Q

Severe atherosclerotic disease early in life, corneal arcus, tendon xanthomas (classically in Achilles tendon)

A

Familial hypercholesterolemia

247
Q

Elevated LDL in familial hypercholesterolemia is due to

A

Defective or absent LDL receptor

248
Q

Inherited disorder of blood vessels; branching skin lesions (telangiectasias), recurrent epistaxis, skin discolorations, arteriovenous malformations (AVMs), GI bleeding, hematuria

A

Hereditary hemorrhagic telangiectasia

249
Q

Hereditary hemorrhagic telangiectasia is aka

A

Osler-Weber-Rendu syndrome

250
Q

Hereditary spherocytosis is due to defect of

A

1) Spectrin 2) Ankyrin

251
Q

Treatment for hereditary spherocytosis

A

Splenectomy

252
Q

Depression, progressive dementia, choreiform movements, and caudate atrophy

A

Huntington disease

253
Q

Neurotransmitter derrangement in Huntington

A

Increased dopamine, decreased GABA, decreased ACh

254
Q

CAG repeat disorder

A

Huntington disease

255
Q

Multiple malignancies at an early agar, aka SBLA cancer (sarcoma, breast, leukaemia, adrenal gland)

A

Li-Fraumeni syndrome

256
Q

Pectus excavatum, hypermobile joints, and long, tapering fingers and toes (arachnodactyly)

A

Marfan

257
Q

Cystic medial necrosis of aorta > aortic incompetence and dissecting aortic aneurysms

A

Marfan

258
Q

Floppy mitral valve

A

Marfan

259
Q

Direction of lens subluxation in Marfan

A

Upward and temporally

260
Q

Optic gliomas, pheochromocytomas, Lisch nodules

A

NF1

261
Q

What are Lisch nodules

A

Pigmented iris hamartomas

262
Q

Bilateral acoustic schwannomas, juvenile cataracts, meningiomas, and ependymomas

A

NF2

263
Q

Neurocutaneous disorder with multi-organ system involvement, characterized by numerous benign hamartomas

A

Tuberous sclerosis

264
Q

Development of numerous tumors, both benign and malignant

A

von Hippel-Lindau disease

265
Q

MC gene mutated in ADPKD

A

PKD1

266
Q

Gene mutated in FAP

A

APC

267
Q

Abnormal in Li-Fraumeni syndrome

A

TP53

268
Q

Gene mutated in Marfan

A

FBN1

269
Q

Gene mutated in MEN 1

A

MEN1

270
Q

Gene mutated in MEN 2A and 2B

A

RET

271
Q

Gene deleted in von Hippel-Lindau disease

A

VHL gene (tumor suppressor)

272
Q

Deleted in cystic fibrosis

A

Phe508

273
Q

Chromosome: ADPKD

A

16 [POLYCYSTIC KIDNEY = 16]

274
Q

Chromosome: FAP

A

5q [POLYP = 5]

275
Q

Chromosome: Huntington

A

4 [Hunting 4 food]

276
Q

Chromosome: Marfan

A

15 [MARFAN SYNDROME = 15 including the space]

277
Q

Chromosome: NF1

A

17 [VON RECKLINGHAUSEN = 17]

278
Q

Chromosome: NF2

A

22

279
Q

Chromosome: von Hippel-Lindau disease

A

3 [VON HIPPEL LINDAU = 3 words]

280
Q

Autosomal recessive diseases

A

Albinism, autosomal recessive polycystic kidney disease (ARPKD), cystic fibrosis, glycogen storage diseases, hemochromatosis, Kartagener syndrome, mucopolysaccharidoses (except Hunter syndrome), phenylketonuria, sickle cell anemia, sphingolipidoses (except Fabry disease), thalassemias, Wilson disease

281
Q

Most common lethal genetic disease in Caucasian population

A

Cystic fibrosis

282
Q

Concentration of chloride in sweat that is diagnostic of CF

A

> 60 mEq/L

283
Q

GI complication seen in newborns with CF

A

Meconium ileus

284
Q

T/F Patients with CF may have infertility

A

T, male absence of vas deferens, female amenorrhea and abnormally thick cervical mucus

285
Q

Vitamin deficiency in CF

A

Fat-soluble vitamins (ADEK)

286
Q

Treatment for CF

A

N-acetylcysteine (cleaves disulphide bonds within mucus glycoproteins

287
Q

Gene defect in cystic fibrosis

A

CFTR

288
Q

What does the CFTR gene encode

A

ATP-gated chloride channel that secretes chloride in the lungs and GIT, and reabsorbs chloride in sweat glands resulting in a compensatory increase in Na reabsorption

289
Q

Chromosome: Cystic fibrosis

A

7

290
Q

X-linked disorder typically due to frameshift (deletions, duplications, or nonsense) mutations

A

Duchenne muscular dystrophy

291
Q

Gene deleted in Duchenne muscular dystrophy

A

Dystrophin gene (DMD)

292
Q

The largest protein-coding human gene

A

Dystrophin gene (DMD)

293
Q

Progress of muscle weakness in Duchenne muscular dystrophy

A

Pelvic girdle > superiorly

294
Q

Pseudohypertrophy of calf muscles in Duchenne muscular dystrophy is due to

A

Fibrofatty replacement of muscle

295
Q

Maneuver: Patients use upper extremities to help them stand up

A

Gower maneuver

296
Q

Gait in Duchenne muscular dystrophy

A

Waddling

297
Q

Onset of Duchenne muscular dystrophy

A

Less than 5 y/o

298
Q

Preliminary diagnosis of Duchenne muscular dystrophy

A

Elevated CPK and aldolase

299
Q

Confirmatory diagnosis of Duchenne muscular dystrophy

A

Western blot and muscle biopsy

300
Q

X-linked disorder typically due to non-frameshift insertions in dystrophin gene

A

Becker

301
Q

Becker vs Duchenne: More severe

A

Duchenne

302
Q

Onset of Becker

A

Adolescence or adulthood

303
Q

2nd most common cause of genetic intellectual disability (after Down syndrome)

A

Fragile X syndrome

304
Q

CGG repeat disorder

A

Fragile X syndrome

305
Q

Findings in Fragile X syndrome

A

Xtra large testes, jaw, and ears

306
Q

Gene affected in Fragile X syndrome

A

FMR1

307
Q

Cardiac abnormality associated with Fragile X syndrome

A

Mitral valve prolapse

308
Q

GAA repeat disorder

A

Friedreich ataxia

309
Q

CTG repeat disorder

A

Myotonic dystrophy

310
Q

3 autosomal trisomies

A

13 [Puberty] Patau; 18 [Elect] Edward; 21 [Drink] Down

311
Q

Gap between 1st 2 toe

A

Down

312
Q

Brushfield spots

A

Down

313
Q

Rocker- bottom feet

A

Edward and Patau

314
Q

Micrognathia

A

Edward

315
Q

Microphthalmia and microcephaly

A

Patau

316
Q

Cleft liP/Palate

A

Patau

317
Q

Early-onset Alzheimer disease

A

Chrom 21 codes for amyloid precursor protein

318
Q

Increased risk of ALL and AML

A

Down

319
Q

95% of cases of Down syndrome is due to

A

Meiotic nondisjunction

320
Q

Clenched hands with overlapping fingers

A

Edward

321
Q

2nd most common trisomy resulting in live birth

A

Edward

322
Q

Most common viable chromosomal disorder

A

Down

323
Q

Most common cause of genetic intellectual disability

A

Down

324
Q

Chromosome: Cri-du-chat

A

5, short arm (p)

325
Q

Chromosome: Wilms tumor

A

11

326
Q

Chromosome: DiGeorge

A

22 (22q11)

327
Q

X-chromosome

A

1) Fragile X 2) X-linked agammaglobulinemia 3) Klinefelter

328
Q

Occurs when the long arms of 2 acrocentric chromosomes (chromosomes with centromeres near their ends) fuse at the centromere and the 2 short arms are lost

A

Robertsonian translocation

329
Q

Cardiac abnormality in Cri du chat

A

VSD

330
Q

Elfin facies; extreme friendliness with strangers

A

Williams syndrome

331
Q

Chromosome: Williams syndrome

A

7

332
Q

Aberrant development of 3rd and 4th branchial pouches

A

DiGeorge (thymic, parathyroid, cardiac defects; Velocardial syndrome (palate, facial, cardiac defects)

333
Q

All water-soluble vitamins wash out easily from body except ___

A

B12 and folate (stored in liver)

334
Q

Clenched hands with overlapping fingers

A

Edward

335
Q

Uses ATP to add high-energy phosphate group onto substrate

A

Kinase

336
Q

Adds inorganic phosphate onto substrate without using ATP

A

Phosphorylase

337
Q

Removes phosphate group from substrate

A

Phosphatase

338
Q

Catalyzes oxidation-reduction reactions

A

Dehydrogenase

339
Q

Adds hydroxyl group (_OH) onto substrate

A

Hydroxylase

340
Q

Transfers CO2 groups with the help of biotin

A

Carboxylase

341
Q

Relocates a functional group within a molecule

A

Mutase

342
Q

Rate-limiting enzyme: Glycolysis

A

PFK-1

343
Q

Rate-limiting enzyme: Gluconeogenesis

A

Fructose-1,6-bisphosphatase

344
Q

Rate-limiting enzyme: TCA cycle

A

Isocitrate dehydrogenase

345
Q

Rate-limiting enzyme: Glycogenesis

A

Glycogen synthase

346
Q

Rate-limiting enzyme: Glycogenolysis

A

Glycogen phosphorylase

347
Q

Rate-limiting enzyme: HMP shunt

A

Glucose-6-phosphate dehydrogenase (G6PD)

348
Q

Rate-limiting enzyme: De novo pyrimidine synthesis

A

Carbamoyl phosphate synthetase II

349
Q

Rate-limiting enzyme: De novo purine synthesis

A

Glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase

350
Q

Rate-limiting enzyme: Urea cycle

A

Carbamoyl phosphate synthetase I

351
Q

Rate-limiting enzyme: Fatty acid synthesis

A

Acetyl-CoA carboxylase (ACC)

352
Q

Rate-limiting enzyme: Fatty acid oxidation

A

Carnitine acyltransferase I

353
Q

Rate-limiting enzyme: Ketogenesis

A

HMG-CoA synthase

354
Q

Rate-limiting enzyme: Cholesterol synthesis

A

HMG-CoA reductase

355
Q

Rate-limiting enzyme: Heme synthesis

A

ALA synthase

356
Q

Regulators of enzyme: PFK-1

A

AMP _, fructose-2,6-bisphosphate _; ATP _, citrate _

357
Q

Regulators of enzyme: Fructose-1,6-bisphosphatase

A

ATP _, acetyl-CoA _; AMP _, fructose-2,6-bisphosphate _

358
Q

Regulators of enzyme: Isocitrate dehydrogenase

A

ADP_; ATP _, NADH _

359
Q

Regulators of enzyme: Glycogen synthase

A

Glucose-6-phosphate _, insulin _, cortisol _; Epinephrine _, glucagon _

360
Q

Regulators of enzyme: Glycogen phosphorylase

A

Epinephrine _, glucagon _, AMP _; Glucose-6-phosphate _, insulin _, ATP _

361
Q

Regulators of enzyme: Glucose-6-phosphate dehydrogenase (G6PD)

A

NADP+ _; NADPH _

362
Q

Regulators of enzyme: Carbamoyl phosphate synthetase II

A

ATP _; UTP _

363
Q

Regulators of enzyme: Glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase

A

AMP _, inosine monophosphate (IMP) _, GMP _

364
Q

Regulators of enzyme: Carbamoyl phosphate synthetase I

A

N-acetylglutamate _

365
Q

Regulators of enzyme: Acetyl-CoA carboxylase (ACC)

A

Insulin _, citrate _; Glucagon _, palmitoyl-CoA _

366
Q

Regulators of enzyme: Carnitine acyltransferase I

A

Malonyl-CoA _

367
Q

Regulators of enzyme: HMG-CoA reductase

A

Insulin _, thyroxine _; Glucagon _, cholesterol _

368
Q

Enzyme deficient in mild galactosemia

A

Galactokinase

369
Q

Enzyme deficient in severe galactosemia

A

Galactose-1-phosphate uridyltransferase

370
Q

Catalyzes INTERCONVERSION of glucose-1-phosphate and glucose-6-phosphate

A

Hexokinase/glucokinase

371
Q

Enzyme deficient in von Gierke

A

Glucose-6-phosphatase (INTERCONVERSION between glucose and glucose-6-phosphate)

372
Q

Glucose-6-phosphate dehydrogenase, catalyzes what

A

Glucose-6-phosphate to 6-phosphogluconolactone

373
Q

Require thiamine as a cofactor

A

1) Transketolase 2) Pyruvate dehydrogenase 3) _-ketoglutarate dehydrogenase

374
Q

Aerobic metabolism of glucose produces ___ net ATP via malate-aspartate shuttle

A

32

375
Q

Malate-aspartate shuttle is found in what organs

A

Heart and liver

376
Q

Aerobic metabolism of glucose produces ___ net ATP via glycerol-3-phosphate shuttle

A

30

377
Q

Glycerol-3-phosphate shuttle is found in what organ

A

Muscle

378
Q

Anaerobic glycolysis produces ___ net ATP per glucose molecule

A

2

379
Q

___ causes glycolysis to produce zero net ATP

A

Arsenic

380
Q

Carrier molecule: Phosphoryl groups

A

ATP

381
Q

Carrier molecule: Electrons

A

NADH, NADPH, FADH2

382
Q

Carrier molecule: Acyl groups

A

CoA, lipoamide

383
Q

Carrier molecule: CO2

A

Biotin

384
Q

Carrier molecule: Aldehydes

A

TPP

385
Q

Carrier molecule: 1-carbon units

A

Tetrahydrofolates

386
Q

NAD+ is from what vitamin

A

B3

387
Q

FAD+ is from what vitamin

A

B2

388
Q

Electron acceptor that is generally used in catabolic processes to carry reducing equivalents away

A

NAD+

389
Q

Electron acceptor that is used in anabolic processes (steroid and fatty acid synthesis) as a supply of reducing equivalents

A

NADPH

390
Q

NADPH is a product of the ___ shunt

A

HMP

391
Q

NADPH is used in (4)

A

1) Anabolic processes 2) Respiratory burst 3) Cytochrome P-450 system 4) Glutathione reductase

392
Q

1st step of glycolysis which also serves as the 1st step of glycogen synthesis in the liver

A

Phosphorylation of glucose to yield glucose-6-phosphate

393
Q

Phosphorylation of glucose to yield glucose-6-phosphate is catalyzed by

A

Hexokinase/glucokinase

394
Q

Hexokinase vs glucokinase: Induced by insulin

A

Glucokinase

395
Q

Hexokinase vs glucokinase: Feedback-inhibited by glucose-6-phosphate

A

Hexokinase

396
Q

Hexokinase vs glucokinase: Gene mutation associated with maturity-onset diabetes of the young (MODY)

A

Glucokinase

397
Q

Steps in glycolysis that require ATP

A

1) Gluc > Gluc6P by hexokinase/glucokinase 2) Fruc6P > Fruc1,6BP

398
Q

Steps in glycolysis that produce ATP

A

1) 1,3BPG > 3PG via phosphoglycerate kinase 2) PEP > pyruvate via pyruvate kinase

399
Q

___ and ___ are the same bifunctional enzyme whose function is reversed by phosphorylation by protein kinase A

A

FBPase-2 (fructose bisphosphatase-2) and PFK-2

400
Q

FBPase-2 vs PFK-2, active in fasting state

A

FBPase-2 (Fruc2,6BP is converted to Fruc6P > more glycolysis, less gluconeogenesis)

401
Q

FBPase-2 vs PFK-2, active in fed state

A

PFK-2 (Fruc6P is converted to Fruc2,6BP instead of Fruc1,6BP > less glycolysis, more gluconeogenesis

402
Q

Mitochondrial enzyme complex linking glycolysis and TCA cycle

A

Pyruvate dehydrogenase complex

403
Q

Pyruvate dehydrogenase complex is active in, fed vs fasting state

A

Fed

404
Q

Pyruvate dehydrogenase complex is activated vs inhibited by exercise

A

Activated

405
Q

Pyruvate dehydrogenase complex is similar to the ___ (same cofactors, similar substrate and action) of the TCA cycle

A

_-ketoglutarate dehydrogenase complex

406
Q

Pyruvate dehydrogenase complex, reaction catalyzed

A

_-ketoglutarate > succinyl-CoA

407
Q

Inhibits lipoic acid

A

Arsenic

408
Q

Findings in arsenic poisoning

A

Vomiting, rice-water stools, garlic breath

409
Q

Treatment for pyruvate dehydrogenase complex deficiency

A

Inc intake of ketogenic nutrients

410
Q

The only purely ketogenic amino acids

A

Lysine, Leucine [Think onLy pureLy ketogenic]

411
Q

Pyruvate metabolic pathway: Carries amino groups to the liver from muscle

A

Alanine of alanine aminotransferase (cofactor: B6)

412
Q

Pyruvate metabolic pathway: Oxaloacetate can replenish TCA cycle or be used in gluconeogenesis

A

Pyruvate carboxylase (cofactor: biotin)

413
Q

Pyruvate metabolic pathway: Transition from glycolysis to the TCA cycle

A

Pyruvate dehydrogenase (co-factors: B1, B2, B3, B5, lipoic acid)

414
Q

Pyruvate metabolic pathway: End of anaerobic glycolysis (major pathway in RBCs, WBCs, kidney medulla, lens, testes, and cornea)

A

Lactic acid dehydrogenase (c0-factor: B3)

415
Q

Products of TCA cycle

A

1) 3 NADH 2) 2 CO2 3) 1 FADH2 4) 1 high-energy compound (GTP)

416
Q

Electrons from glycolysis enters the mitochondria via

A

1) Malate-aspartate shuttle 2) Glycerol-3-phosphate shuttle

417
Q

FADH2 from glycolysis are transferred to what complex of the ETC

A

II

418
Q

How many ATP are produced via ATP synthase

A

1.5

419
Q

Inhibit the ETC by causing a decrease in proton gradient and block of ATP synthesis

A

Electron transport inhibitors

420
Q

Inhibit the ETC by causing an increase in proton gradient

A

ATP synthase inhibitors

421
Q

Increases mitochondrial membrane permeability, causing a decrease in proton gradient and increase in O2 consumption; ATP synthesis stops but ETC continues

A

Uncoupling agents

422
Q

ATP synthase inhibitor of the ETC

A

Oligomycin

423
Q

What are the uncoupling agents

A

1) 2,4-dinitrophenol 2) Aspirin 3) Thermogenin

424
Q

Irreversible enzymes of gluconeogenesis

A

1) Pyruvate carboxylase 2) PEP carboxykinase 3) Fructose-1,6- bisphosphatase 4) Glucose-6-phosphatase [Think Pathway Produces Fresh Glucose]

425
Q

Irreversible enzyme of gluconeogenesis seen in the mitochondria

A

Pyruvate carboxylase

426
Q

Irreversible enzymes of gluconeogenesis seen in the cytosol

A

1) PEP carboxykinase 2) Fructose-1,6-bisphosphatase

427
Q

Irreversible enzyme of gluconeogenesis seen in the ER of liver cells

A

Glucose-6-phosphatase

428
Q

Pyruvate > oxaloacetate

A

Pyruvate carboxylase

429
Q

Oxaloacetate > PEP

A

PEP carboxykinase

430
Q

Fructose-1,6-bisphosphate > fructose-6-phosphate

A

Fructose-1,6- bisphosphatase

431
Q

Glucose-6-phosphate> glucose

A

Glucose-6-phosphatase

432
Q

Gluconeogenesis occurs primarily in the

A

Mitochondria and cytosol of liver (other sites: kidney, intestinal epithelium)

433
Q

Metabolic process that serves to maintain euglycemia in fasting

A

Gluconeogenesis

434
Q

Muscle cannot participate in gluconeogenesis because it lacks

A

Glucose-6-phosphatase

435
Q

Odd-chain vs even-chain fatty acids: Source of substrate for gluconeogenesis

A

Odd-chain

436
Q

Even-chain fatty acids cannot produce new glucose because ___

A

They yield only acetyl-CoA equivalents

437
Q

Odd-chain fatty acids yield ___ during metabolism, which can enter the TCA cycle and undergo gluconeogenesis

A

1 propionyl-CoA

438
Q

1 propionyl-CoA from odd-chain fatty acids can enter the TCA cycle as

A

Succinyl-CoA

439
Q

Provides a source of NADPH from abundantly available glucose-6-P

A

HMP shunt (pentose phosphate pathway)

440
Q

NADPH is required for biosynthesis of (3)

A

1) Fatty acids 2) Cholesterol 3) Nucleotides (ribose) 4) Glycolytic intermediates

441
Q

2 phases of HMP shunt

A

1) Oxidative 2) Non-oxidative

442
Q

HMP shunt occurs in

A

Cytoplasm

443
Q

Number of ATP used and produced in HMP shunt

A

NONE

444
Q

Organs where HMP shunt can be found

A

1) Lactating mammary glands 2) Liver 3) Adrenal cortex 4) RBCs

445
Q

Site of fatty acid or steroid synthesis

A

Adrenal cortex

446
Q

HMP reaction that is irreversible

A

Oxidative reaction: G6PD

447
Q

HMP reaction that is reversible

A

Non-oxidative: Phosphopentose isomerase, transketolases

448
Q

Most common human enzyme deficiency; more prevalent in blacks

A

G6PD deficiency

449
Q

Inheritance pattern of G6PD deficiency

A

X-linked recessive

450
Q

G6PD deficiency increases resistance against what infection

A

Malaria

451
Q

RBCs contain ___ in patients with G6PD deficiency

A

Heinz bodies (denatured/precipitated Hgb due to oxidative stress)

452
Q

RBCs appear as ___ in patients with G6PD

A

Bite cells, due to phagocytic removal of Heinz bodies by splenic macrophages

453
Q

Metabolic disorder resulting from deficiency of fructokinase

A

Essential fructosuria

454
Q

Essential fructosuria is a benign, asymptomatic condition because

A

Fructose is not trapped in cells

455
Q

Fructose intolerance is a hereditary deficiency of ___

A

Aldolase B

456
Q

In fructose intolerance, ___ accumulates

A

Fructose-1-phosphate

457
Q

Glucose level in fructose intolerance

A

Hypoglycemia

458
Q

Why is there hypoglycemia in fructose intolerance

A

Decrease in available phosphate > inhibition of glycogenolysis and gluconeogenesis

459
Q

Symptoms of fructose intolerance present following consumption of ___

A

Fruit, juice, or honey

460
Q

T/F In fructose intolerance, urine dipstick will be positive

A

F

461
Q

T/F In fructose intolerance, reducing sugar can be detected in the urine

A

T

462
Q

Nonspecific test for inborn errors of carbohydrate metabolism

A

Detection of reducing sugars in urine

463
Q

Treatment for fructose intolerance

A

Decrease intake of both fructose and sucrose (glucose + fructose)

464
Q

In galactokinase deficiency, ___ accumulates if galactose is present in diet

A

Galactitol

465
Q

Important finding in galactokinase deficiency that manifests as failure to track objects or develop a social smile

A

Infantile cataracts

466
Q

Classic galactosemia is due to deficiency of

A

G1PUT

467
Q

Classic galactosemia can lead to ___ sepsis in neonates

A

E. coli

468
Q

Treatment for classic galactosemia

A

Exclude galactose and lactose (galactose + glucose) from the diet

469
Q

Galactose is converted to galactitol (its alcohol counterpart) by what enzyme

A

Aldose reductase

470
Q

Glucose is converted to sorbitol (its alcohol counterpart) by what enzyme

A

Aldose reductase

471
Q

Some tissues convert sorbitol to fructose using ___; tissues with an insufficient amount of this enzyme are at risk for intracellular sorbitol accumulation, causing osmotic damage

A

Sorbitol dehydrogenase

472
Q

BOTH aldose reductase and sorbitol dehydrogenase are found in what organs

A

1) Liver 2) Ovaries 3) Seminal vesicles

473
Q

Organs/cells that have only aldose reductase

A

1) Schwann cells 2) Retina 3) Kidneys

474
Q

Organ that has both aldose reductase and sorbitol dehydrogenase but PRIMARILY aldose reductase

A

Lens

475
Q

Lactose intolerance characterized by an age-dependent decline after childhood, common in people of Asian, African, or Native American descent

A

Primary lactose intolerance

476
Q

Lactose intolerance characterized by loss of brush border due to gastroenteritis (rotavirus), autoimmune disease, etc

A

Secondary lactose intolerance

477
Q

Rare form of lactose deficiency and is due to defective gene

A

Congenital

478
Q

Amino acids found in proteins

A

L-amino acids

479
Q

Essential amino acids

A

[PVT TIM HALL always Argues but never TYRes] 1) Phenylalanine 2) Valine 3) Threonine 4) Isoleucine 5) Methionine 6) Histidine 7) Arginine 8) Lysine 9) Leucine

480
Q

Amino acids that are both glucogenic and ketogenic

A

[KiLL PITT] 1) Phenylalanine 2) Isoleucine 3) Tryptophan 4) Threonine

481
Q

Acidic amino acids

A

1) Aspartic acid 2) Glutamic acid

482
Q

Basic amino acids

A

Basic HAL 1) Histidine 2) Arginine 3) Lysine

483
Q

Most basic amino acid

A

Arginine

484
Q

Amino acids that are negatively charged at body pH

A

Acidic a.a.

485
Q

Amino acids that have no charge at body pH

A

Basic a.a.

486
Q

Amino acids that are required during period of growth

A

1) Arginine 2) Histidine

487
Q

Conversion of alanine to glucose and vice versa; an intermediate in amino acid catabolism

A

Cahill cycle

488
Q

Conversion of lactate to glucose and vice versa; an intermediate in amino acid catabolism

A

Cori cycle

489
Q

Hyperammonemia results in excess NH4+ (ammonium ion), which depletes what substrate of the TCA cycle

A

_-ketoglutarate

490
Q

Given to patients with hyperammonemia to acidify the GI tract and trap NH4+ for excretion

A

Lactulose

491
Q

Given in patients with hyperammonemia to decrease colonic ammoniagenic bacteria

A

Rifaximin

492
Q

___ or ___ may be given to patients with hyperammonemia (both of which bind amino acid and lead to excretion)

A

Benzoate or phenylbutyrate

493
Q

Required cofactor for carbamoyl phosphate synthetase I of urea cycle, the deficiency of which leads to hyperammonemia

A

N-acetylglutamate synthase deficiency

494
Q

Most common urea cycle disorder

A

Ornithine transcarbamylase deficiency

495
Q

The only X-linked recessive urea cycle disorder

A

Ornithine transcarbamylase deficiency

496
Q

Ornithine transcarbamylase deficiency leads to excess ___ which is converted to orotic acid (pyrimidine synthesis)

A

Carbamoyl phosphate

497
Q

In contrast to orotic aciduria, ornithine transcarbamylase does not present with

A

Megaloblastic anemia

498
Q

Glycine derivatives

A

1) Porphyrin 2) Heme

499
Q

Glutamate derivatives

A

1) GABA 2) Glutathione

500
Q

Arginine derivatives

A

1) NO 2) Creatine 3) Urea

Biochemistry (5 decks)

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