other people final review Flashcards
what is the shine-Dalgarno sequence?
sequence upstream of AUG in prokaryotes
What is the Kozak context?
sequence embedded AROUND AUG
what does a peptidyl transferase catalyze?
forms the bond between two amino acids in the peptidyl site and aminoacyl site while they are still bound to tRNA, and a stop codon is not recognized and a water molecule is bound
Actinomycin-D and acridine
Inhibits RNA elongation by intercalating into the DNA template (transcription inhibitor)
Streptomycin function
Binds to the 30s subunit and alters its structure to inhibit the initiation of protein synthesis in prokaryotes
Tetracyclines
Interacts with small ribosomal subunits and blocks the access of aminoacyl-tRNA to the mRNA-ribosome complex in prokaryotes
Puromycin function
Resembles aminoacyl-tRNA and is incorporated into the growing chain and inhibits further elongation in BOTH prokaryotes and eukaryotes
Chloramphenicol function
inhibits prokaryotic peptidyltransferase, and can also inhibit mitochondrial protein synthesis
Clindamycin and Erythromycin function
Binds irreversibly to the 50s subunit in bacteria
Diphtheria toxic
Inactivates the eukaryotic elongation factor (eEF-2) which prevents translocation of ribosome
Rifampicin
Inhibits initiation of bacterial RNA synthesis by binding to the b subunit of the polymerase for TB treatment
(Inhibits Transcription)
a-amanitin
Mushroom toxin
Blocks eukaryotic Pol II and III. Blocks all transcription
what are the effects of glucose and lactose on the lac operon?
low glucose= cap bound
lactose unavailable= repressor bound
low glucose + low lactose= lac not expressed
low glucose + lactose= lac strongly expressed
glucose + low lactose= lac not expressed
glucose + lactose= very low expression
“use lactose if glucose not available”
do regulatory proteins need to be on the same piece of DNA that they regulate?
Yes, DNA bending can bring an activator protein, bound to an enhancer element into contact with transcription complex
How to glucocorticoids regulate gene transcription?
- steroid diffuses into cells and binds to receptor protein
- receptor-steroid complex goes into nucleus
- the complex binds to a regulatory sequence
also called hormone response element
similarities between enhancer elements
SNOW DROP
how to test pneumonic
Southern- DNA
Northern- RNA
skip O
Western- Protein
DNA forms?
b-form= primary form
a-form= DNA with RNA hybrid
z-form= reverse helix form, usually near promotors
pol alpha, primase, and DNA ligase function
pol alpha synthesizes DNA
primase synthesizes a RNA primer
ligase seals nick at end of lagging strand and used in DNA repair
sickle cell anemia mutation
amino acid change from Glu to Val makes a “sticky” point which associates with other heme groups
hemoglobin R versus T state
R state “left shift” high affinity state (reduces oxygen delivery to tissues) when theres more oxygen available
T state “right shift” is low affinity (increased oxygen delivery to tissues)
what are the essential amino acids
PVT TIM HaLL
phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, lysine
how is aspartate synthesized using coupled transamination
- alanine broken into pyruvate by alanine aminotransferase and gives off glutamate
- glutamate converted into alpha-ketoglutarate by aspartate aminotransferase which gives off a aspartate
synthesis of tyrosine? cofactor and deficiency
phenylalanine converted using phenylalanine hydroxylase which requires tetrahydrobiopterin
Deffect causes buildup of phenylalanine which causes phenylketonuria
what substances are glucogenic?
amino acids, lactate, glycerol, and propionate
