Day 1 biochem Flashcards
(45 cards)
What AA only have ONE codon?
tryptophan, methionine, and selenocysteine
what is the initiation codon?
methionine
- *AUG
- *every protein starts with THIS Amino Acid!
(UAA, UGA, and UAG are stop codons for no AA)
coenzyme cofactors apoenzyme haloenzyme zymogens proenzyme
coenzyme= nonprotein/organic part cofactors= organic molecules (coenzyme) or ions (metal)
apoenzyme= protein portein of complete enzyme
haloenzyme= complete, catalytically active enzyme system
zympgens= enzymatically INactive PREcursors of proteolytic enzymes (converted to acitve by removal of peptide group)
proenzyme= inactive precursor of an enzyme
describe clots
- prothrombin (from liver; need calcium and thromboplastin) > thrombin
- thrombin acts on fibrinogen (in plasma)
- fibrinogen > fibrin to MAKE clots
- plasminogen (in blood) makes plasmin to BREAK down clots
what are the two markers for osteoblastic activity?
1) alkaline phosphatase
- - funtions at 8.6 pH
- - bone mineralization and hydrolysis of phosphoric esters
2) osteocalcin
- - 2nd most abundant protein in bone after type 1 collagen
*pyrophosphatase MAY play a role in mineralization as well
alkaline phosphatase vs acid phosphatase
Found where? High levels cause?
alkaline phosphatase
- bone forming (ostreoBlastic; 8.6 pH)
- HIGH levlers= paget’s disease and osteaosarcoma
- Low levels hypophosphatasia
acid phosphatase
- prostate gland (5.4 pH)
- HIGH levels in prostate carcinoma
what is the first enzyme to appear after a heart attack (myocardial infarction)?
creatine kinase
then glut-ox and glut-pyruvate from the liver appear
(and lactate dyhudrogenase will elevate)
a-amylase vs b and y-amylase vs isomaltase
a-amylase= cleave 1,4 startch, faster bc acts anywhere
** both saliva and pancreatic enzymes
b-amylase= slower bc cuts every TWO 1,4 links
y-amylase= cleaves both 1,4 and 1,6
isomaltase= cleave 1,6
trypsin
- an enteropeptidase; catalyze the hydrolysis of peptide bonds in the interior of a polypeptide chain
- an activator for ALL zymogens of pancreatic proteases
an increase in pH means a stronger ability to bind ____ions? (think of proteins)
hydrogen ions
what is the MOST important buffer in extracellular fluid? why?
carbonic acid; easily breaks water into carbon dioxide which is readily removed via lungs
*bicarbonate, hemoglobin and albumin are also buffers used in blood to regulate pH
acid vs base in buffer
acid= salt= donor (aciDonor)
base= proton acceptor
on what side of the membrane are glycoproteins, phosphatidylserine, phosphatidylethanolamine, and glycolipids found on a membrane?
outer= carbohydrates as glycoproteins and glycolipids
inner= lipds phosphatidylethanolamine and phosphatidylserine
polar vs nonpolar… which one crosses lipid bylayer?
polar= hydrophilic, soluble in water, active transport
— ions, glucose, urea
nonpolar= hydrophobic, NOT soluble in water, simple diffusion
— oxygen, carbon dioxide, alcohol
*small and nonpolar can cross
trademark of HIV/AIDS? what inhibits it?
AIDS uses enzyme reverse transcriptase (a DNA polymerase that uses RNA template)
**trademark of a retrovirus; HIV is a retrovirus^^
*drug AZT (thymine analog) is a competitive inhibitor of HIV reverse transcriptase
1) initiation codon?
2) termination codon?
3) wobble?
4) coded for by ONE codon?
1) methionine aka AUG, all proton start with this
2) UAA, UGA, UAG, stop codon, no AA
3) wobble happens in the 3rd position of each codon
4) tryptophan, methionine, slesnocysteine coded for by ONE codon
what is the group of ligases (enzymes)that ensures the correct AA is attached to the correct tRNA/anticodon?
+++ HOW does ligase work?
amino acyl-tRNA synthetase
- *individual enzymes are HIGHLY specific for one AA
- NO error checking occurs in transnational process of ribosome
+++ Ligase uses a molecule of ATP to activate the 5’ end; ATP HYDROLYSIS
70 vs 80 ribosome are found where?
70 (30s + 50s) = in bacteria and cholorplasts
80 (40s + 60s) in eukaryotic
transcription
process in which DNA is template for ALL forms of RNA and enzyme RNA polymerase is used
*translation is RNA to protein
xanthine oxidase
catalyzes the formation of uric acid from purine bases
*purine ingested in diet and excreted in urin
where is phosphodiester bonds found?
Linked how?
between 3’ OH (hydroxyl group) on one sugar and a 5’ OH on the next sugar connected with a phosphate
*linked via a condensation rxn!
DNA/RNA hydrophilic or hydrophobic?
hydroPHILIC and highly polar
*hydroxyl groups on sugars form hydrogen bonds with water
the ribose phosphate portion of purine and pyrimidine nucleotides comes from?
5-phosphoribosyl-1-pyrophosphate (PRPP)
* PRPP is synthesized from ATP and ribose 5-phosphate, which is primarily formed by the pentose phosphate pathway
zwitterion
dipolar ions
* at physiological pH all AA have both a - carboxyl group (-COO) and a + amino group (NH3+)
