Biochem Final

noncompetitive inhibitor

binds either enzyme or enzyme substrate complex, Km is unchanged in the presence of this type of inhibitor

competitive inhibitor

structurally similar to substrate, when present Km of enzyme will increase, prevents substrate from binding enzyme

Enatiomers

Nonsuperimposable mirror images

phosphatases

RAS, FBPase-2

oncogenes

RET, KIT, MET (inherited). Control cell function and division. RET-Multiple endocrine neoplasia type 2 (MEN2). KIT- hereditary gastrointestinal stromal tumors (GISTs)

Spherical NAs

SNAs use a metal core, wide variety of groups. high density in nucleic acids leads to interactions with membrane bound scavenger proteins, taken up through endocytosis. do not trigger immune response, not degraded by endonuclease. can be used to analyze and treat many diseases with a genetic basis. regulates gene expression.

siRNA

Small interfering RNA. First discovered in C.elegans. Double stranded RNA sequences. Short, micro, and hairpin variants. Exogeneous and endogeneous pathways. Target specific mRNA, Interfere with heterochromatin formation, defend against viral RNA, disrupt translation of mRNA

Tumor suppressor genes

TP53 (p53), BRCA1, BRCA2, APC, and RB1. Specifically p53 protein mutations have been found in roughly 50% of all cancers

AptNAs

Aptamer nucleic acids, Designed 2D and 3D nucleic acid structures. Cell surface protein recognition, SELEX generated DNA sequences, Drug loading sites. Passive uptake to cells good for some cancers not others. Targeting specific cancer cell lines Doxorubcin

Activation of PKA

Cytosolic cAMP concentration increases, Two cAMP molecules bind to each PKA regulatory subunit, The regulatory subunits move out of the active sites of the catalytic subunits and the R2C2 complex dissociates, The free catalytic subunits interact with proteins to phosphorylate Ser or Thr residues,

transcription and translation

DNA>RNA>protein

Epimers

Differ at one of several asymmetric carbon atoms

Kinases

ERK2, MAPK, BCR-Abl, PKA, insulin receptor, HER2/neu, EGFR

Put the steps of the Edman degradation in the correct order

Treat with phenyl isothiocyanate, treat with trifluoroacetic acid, extract the derivatized amino acid, identify the phenylthiohydantion

One reason that ATP is a source of energy is that the products of ATP hydrolysis have less free energy than the reactants. Why?

hydrogen bonding between free phosphate and water, resonance stabilization of free phosphate, electrostatic repulsion in ATP

Chemotherapy

in general target cell division. these drugs usually target DNA replication -nucleoside derivatives. Cells will incorporate the new chemical into the DNA and it stops the replication process

Diastereoisomers

isomers that are not mirror images

Allosteric enzymes

may have binding sites for regulatory molecules that are separate from active sites, generally have more than one subunit, interconvert between a more active form and less active form

ATP is a source of free energy that drives unfavorable reactions. a) Which of the following processes are coupled to the dephosphorylation of ATP?

membrane transport that maintains Na levels in cells, myosin action during muscle contraction, de novo (from scratch) anabolism of nucleotides

Taxol

stabilizes the microtubules used in mitosis, does not affect DNA but rather the structures that allow the cell to divide. Natural product from the bark of a pacific yew tree

uncompetitive inhibitor

when present Km of enzyme will decrease, bind enzyme substrate complex only