Untitled Flashcard Set

tertiary structure of a protein

Primarily stabilized by interactions among R-groups.

hydrophobic amino acids in a soluble protein

Most commonly found buried in the core.

secondary structure includes

α-helices and β-sheets.

enzymes lower activation energy by

Orienting substrates and stabilizing transition states.

substrate analog inhibits an enzyme

By occupying the active site.

SDS in SDS-PAGE gives proteins

A uniform negative charge.

disulfide bonds form between

Cysteines.

quaternary structure describes

Subunit interactions.

Bradford and BCA assays measure

Protein concentration.

2D electrophoresis, proteins are separated first by

Charge (isoelectric point).

Coomassie Blue is used to

Visualize proteins in gels.

Western blotting uses antibodies to detect

Protein of interest.

His-tagged proteins are purified using

Nickel affinity resin.

MALDI-TOF measures

Protein mass-to-charge ratio.

phage display screens for

Protein binding interactions.

yeast two-hybrid detects

Protein–protein interactions.

co-immunoprecipitation identifies

Protein–protein binding partners.

sigma factor’s primary job is to

Recognize promoter sequences.

Heat-shock genes in E. coli use

σ32 (RpoH).

Under normal temperatures, RpoH is

Quickly degraded.

anti-sigma factors

Bind sigma factors and prevent polymerase binding.

positive regulation requires

An activator to stimulate transcription.

the lac operon is ON when

Glucose low, lactose present.

allolactose functions as a(n)

Inducer that inactivates LacI.

CAP–cAMP activates transcription when

Glucose is low.

two-component systems use

Sensor kinase + response regulator.

H-NS functions to

Compact DNA and silence genes.

anti-termination allows RNA polymerase to

Read through a terminator.

the mediator complex

Links activators/repressors to RNA polymerase II.

enhancers

Can act from long distances.

insulators block

Enhancer action or heterochromatin spread.

CTCF binds insulators when

Unmethylated.

euchromatin is

Loosely packed, active.

histone acetylation generally

Opens chromatin and increases transcription.

HDACs cause

Condensation and repression.

Polycomb group proteins

Silence genes using histone modifications.

DNA methylation usually

Blocks TF binding and recruits HDACs.

X-inactivation is triggered by

Xist RNA coating the chromosome.

antisense RNA regulates genes by

Base-pairing with mRNA to block translation.

CsrA blocks translation by binding

The Shine-Dalgarno sequence.

RNase III activates translation of adhE by

Cleaving the mRNA to expose the RBS.

IRP binds ferritin mRNA when iron is

Low.

When iron is high, IRP1 functions as

A Krebs cycle enzyme (aconitase).

ribosomal protein operons are regulated so that

Extra ribosomal proteins block their own mRNA.

chloroplast translational activators respond to

Light.

Upstream ORFs usually __ translation of the main ORF.

Decrease.

long 3′UTRs can regulate

Protein localization.

riboswitches regulate by

Changing mRNA secondary structure.

RNA thermosensors work by

Melting a stem-loop to expose the SD sequence.

m6A modifications can cause

Either increased translation or increased degradation, depending on binding proteins.