Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
87 Cards in this Set
- Front
- Back
What molecule is modified by diptheria toxin? Describe the reaction and its effect
|
EF-2 is ADP-ribosylated, which inhibits eukaryotic translation
|
|
Which main translation factors are involved in elongation? Describe their roles
|
EF-Tu brings aa-tRNA into A site, EF-Ts dissociates EF-Tu from GDP allowing its reuse, EF-G moves tRNAs through the ribosome
|
|
What is the start codon? What are the stop codons?
|
Start - AUG
Stop - UAA UAG UGA |
|
What are the primary modifications of mRNA before it is used in translation?
|
5' m7G - TP cap, 3' polyAdenylation
|
|
What is the role of aa-tRNA synthetases?
|
Charges tRNAs - bonds appropriate amino acid to each tRNA
|
|
How are viral RNAs able to "hijack" eukaryotic translation?
|
The IRES domain on viral mRNA binds eIF-4G directly, bypassing PABP and eIF-4Es role in initiation
|
|
In which direction are proteins translated?
|
From N to C terminals
|
|
What are the functions of TIM and TOM proteins?
|
Transport of proteins through the mitochondrial membranes - Chaperones deliver proteins to TOM, which lines up with TIM to allow transport through both membranes
|
|
What are translocons?
|
Protein channels such as TIM/TOM (mito), PEX (peroxisomes), and Sec (ER) that recognize targeting signal sequences to allow peptides to be transported into organelles
|
|
What is the role of Ran-GTPase
|
gating nuclear transport - GTP hydrolyzed during export process
|
|
What is GPI?
|
glycosylphosphatidyl isositol - a membrane anchor that soluble proteins are post-translationally attached to in ER, associates with lipid rafts
|
|
What is the role of Rab-GTPase
|
involved in SNARE docking, the Rab effector protein is on the target compartment
|
|
Which amino acids are K, Q, D and E
|
K - lysine, Q - glutamine, D - aspartic acid, E - glutamic acid
|
|
Describe the changes in tertiary structure associated with the two conformations of PrP
|
PrPc is rich in a-helixes, PrPsc has exposed anti-B sheets
|
|
What are the typical symptoms of parkinsons disease?
|
diminished facial expression, depressed mood, stooped posture, shortened gait, rigidity and tremor
|
|
What are Lewy Bodies and what disease are they associated with?
|
eosinophilic inclusions in surviving neurons composed of a-synculin and ubiquitin filament aggregates. found in parkinsons disease
|
|
What is a-synculin's presumed function in the healthy neuron?
|
Transporting dopamine vessicles down axons
|
|
What neurodegenerative disease is correlated with trinucleotide (CAG) repeats?
|
Huntingtons
|
|
What is "anticipation" as it relates to neurodegenerative diseases and what causes it?
|
Progressively earlier onset of symptoms with inheritance - due to the lengthening of repeating regions during DNA replication - stem loop mechanism
|
|
Name some examples of Prion diseases
|
Kuru, BSEs (mad cow disease), Creutzfield - Jakob Syndrome
|
|
What is the role of lysyl oxidase? What is a necessary cofactor?
|
cross links collagen and elastin fibers - needs copper
|
|
Which is stiffer? Fibrillin or elastin
|
Fibrillin - it stretches by rearranging trandem domains
|
|
Which ECM components have anti-thrombin activity? Why
|
acidic proteoglycans or GAGs (namely heparin) due to their strong anionic character
|
|
Which cellular receptors are largely responsible for binding to extracellular glycoproteins
|
integrins
|
|
What is tenascin? Where is it found?
|
ECM glycoprotein that forms octamers, tendon and mesenchyme
|
|
What is von Willebrand's factor? What is its role?
|
blood glycoprotein, involved in hemostasis, binds to clotting factors and collagen
|
|
Which enzymes are inactive in scurvy?
|
Prolyl hydroxylase and lysyl hydroxylase
|
|
What are some symptoms of Ehler Danlos syndrome?
|
stretchy skin, loose joints, heart valve problems
|
|
A mutation in which protein is responsible for marfans syndrome?
|
fibrillin 1
|
|
Where is laminin found? What is a condition associated with its mutation?
|
In the basal lamina, junctional epidermolysis bullosa
|
|
What is normal serum [HCO3-]
|
24 mEq/L
|
|
Why does the body lower the [HCO3-] following increases in production of organic acids such as ketone bodies?
|
To maintain electrical neutrality in the blood
|
|
Which three ions are used in calculating the AG?
|
Na HCO3 and Cl
|
|
What is the typical cause of saline-responsive metabolic alkalosis?
|
Large volume loss - low filtration rate of HCO3-, plus angiotensin upregulation of Na/H transporter leads to increase [HCO3-]
|
|
What is Bartter's syndrome? What are its typical indications?
|
tubular defect in Na+ reabsorption -> decreased BP -> Na/K pump -> metabolic saline responsive alkalosis with muscle weakness and hypokalemia
|
|
What is a normal AG?
|
12-16 mEq/L
|
|
What receptors are responsible for the adhesion of immune cells such as macrophages and leukocytes to endothelial cells during chemotaxis
|
selectins
|
|
What AA sequence on fibronectin is considered most vital to integrin adhesion
|
RGD
|
|
What is oncotic pressure? Describe its importance to the cardiovascular system
|
The osmostic pressure of the plasma due to plasma proteins. Its balance with hydrostatic pressure controls the filtration and reabsorption of fluid in the capillaries
|
|
Do a-helices or B-sheets have a regular repeated pattern of residue interaction?
|
a-helices do (every fourth AA is H bonded) but B sheets do not. They may have interacting residues that are very separate in primary structure
|
|
What is the EF hand motif and what is its function?
|
a helix-turn-helix separated by 12 residues, conjugates with Ca2+
|
|
Which binds aa-tRNA: EF-Tu GDP or EF-Tu GTP?
|
EF-Tu GTP
|
|
What is the cause and presentation of Williams Beuren syndrome?
|
Deletion of a region of chromosome 7 - leads to "elfin" facial expression, mild retardation, and extremely outgoing personality
|
|
A DNA point mutation results in mRNA that encodes a shorter protein than the wild type gene, what kind of mutation is this?
|
nonsense
|
|
Define gene dosage
|
number of gene copies in the genome
|
|
A single nucleotide is inserted in the DNA sequence of a gene, what kind of mutation will this result in?
|
Frameshift
|
|
How many dogs is ok for a family to have?
|
1 or 2, 10 is certainly too many
|
|
how does acetylation of histones affect gene activity?
|
increases gene expression by loosening chromatin structure for transcription
|
|
what genetic modification is largely responsible for inheritable cell phenotype?
|
epigenetic DNA modification - cytosine methylation patterns
|
|
which nucleotides have 3 H bonds, 2?
|
CG pairs have 3 H bonds, AT pairs have 2
|
|
Which strand of DNA is identical to transcribed RNA, but with T->U?
|
coding strand
|
|
what enzyme unwinds DNA supercoils to relieve stress on the molecule during replication?
|
topoisomerase
|
|
what type of RNA is associated with gene regulation?
|
micro RNA
|
|
what is the sir protein?
|
silent information regulators - deacetylates active nucleosome histones and stabilized heterochromatin structure
|
|
in which direction is dna polymerized?
|
5->3
|
|
describe penicillins mechanism of action
|
acts as a suicide inhibitor of gycopeptide transpeptidase - inhibits synthesis of bacterial cell wall
|
|
what class of drug is allopurinol? what condition is it used to treat?
|
suicide inhibitor of xanthine oxidase - used to treat gout
|
|
what are ACE inhibitors used for? give an example
|
to reduce blood pressue by blocking conversion of angiotensin I to II, captopril
|
|
what antiviral drug was used as an example? what is its mechanism of action?
|
acyclovir - acts as a nucleoside analogue, non specific viral kinase enzymes incorporate it into infected cells DNA - kills infected cells
|
|
what is an apozyme? a holozyme?
|
apozyme - enzyme without its cofactor, holozyme - enzyme cofactor combo
|
|
what is the chemical role of vitamin B and other water solube vitamins
|
metabolic cofactors
|
|
what is an abzyme?
|
a catalytic antibody - an antibody to the transition state
|
|
how will Km change with increasing [E]
|
no change
|
|
How does Vmax change with increasing [E]
|
linearly
|
|
what is the function of DNA polymerase alpha?
|
gap filling and synthesis of lagging strand
|
|
what is the function dna polymerase delta?
|
processive leading strand synthesis
|
|
what is the function of dna polymerase gamma?
|
mitochondrial dna synthesis
|
|
what is the role of single stranded DNA binding protein?
|
to remove hairpin structures from SS dna after helicases separate the strands
|
|
what is the role of single stranded DNA binding protein?
|
to remove hairpin structures from SS dna after helicases separate the strands
|
|
what is the role of single stranded DNA binding protein?
|
to remove hairpin structures from SS dna after helicases separate the strands
|
|
Km decreases with the addition of inhibitor, what kind of inhibitor is being added?
|
competitive
|
|
Vmax decreases but Km remains constant with which kind of inhibitor?
|
non competitive
|
|
what is an uncompetitive inhibitor?
|
binds to ES complex, both Vmax and Km change
|
|
what kind of inhibitor results in parallel lines on lineweaver plot?
|
uncompetitive
|
|
what is an uncompetitive inhibitor?
|
binds to ES complex, both Vmax and Km change
|
|
what kind of inhibitor results in parallel lines on lineweaver plot?
|
uncompetitive
|
|
in lineweaver plot, addition of inhibitor results in lines with an intersection not on either axis, what is this type?
|
mixed noncompetitive
|
|
how is catalytic efficiency measured?
|
kcat/km
|
|
What is southern blotting used for?
|
To detect specific sequence in dna genome
|
|
what is activated flow cytometry? what is it used for?
|
cells marked with flourescent markers are detected while flowing through sorting device. used to quantify cell populations or markers
|
|
which is cytochrome c's role in cell signalling?
|
signals apoptosis
|
|
What is MERRF?
|
myoclonic epilepsy and and ragged red fiber disease - mitochondrial disease - uncontrolled muscle jerking and misshaped mitochondria with crystalline inclusions
|
|
give an example of mitochondrial materials that are supplied by nuclear DNA
|
DNA polymerase gamma, nucleotide carrier, and dna helicase
|
|
what is western blotting used for?
|
to detect specific proteins in solution - separated by electrophoresis and fluorescently tagged with antibody
|
|
what are quinolones?
|
drugs that inhibit dna replication by inhibiting topoisomerases
|
|
what is the mechanism of action of the erythromycin antibiotics?
|
interferes with aminoacyl transfer in the 50s subunit of bacterial ribosomes
|
|
what is an operon?
|
in prokaryotes - a collection of genes forming similar functions which are arranged together on the genome and regulated in concert
|