Term
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Definition
Condensed chromatin wrapped around pos charged nucleosome
Histones are rich in lysine and arginine
H1 is only histone that is not in the nucleosome core |
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Definition
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Definition
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Term
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Definition
| cytosine and adenine are methylated in replication, which allows mismatch repair enzymes to distinguish between old and new strands |
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Term
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Definition
Methylation = inactivation (methylation = mute)
Acetylation = relaxation, allowing transcription |
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Term
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Definition
PURines (A, G) - 2 rings "Pure as Gold"
Pyrimidines (C, T, U) - 1 ring
Guanine has a ketone, Thymine has a methyl
Deamination of cytosine makes a uracil
G-C bond (3 bonds) - strongest bond |
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Term
| Amino acids necessary for Purine synthesis |
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Definition
GAG
Glycine
Aspartate
Glutamine
Also needs THF |
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Term
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Definition
Start with sugar and phosphate (PRPP), add base
PRPP > (PRPP synthetase) IMP > GMP or AMP
RLE: Glutamine PRPP amino transferase |
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Term
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Definition
Temp base (orotic acid), add PRPP, modify
*draw out pathway
Req: Carbamoyl phosphate, Orotic acid, PRPP, UMP > UDP > CTP or dUDP > dTMP
RLE: CPS 2 |
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Term
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Definition
| Ribonucs are synthesized first and converted to deoxyribonucleotides but ribonucleotide reductase |
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Term
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Definition
Involved in 2 pathways:
1: de novo pyrimidine synthesis
2: urea cycle
OTC deficiency leads to an accumulation of carbamoyl phosphate which is then converted to orotic acid |
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Term
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Definition
Inhibits ribonucleotide reductase
Pyrimidine cycle
UDP > dUDP |
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Term
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Definition
Blocks de novo purine synthesis
PRPP > IMP |
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Term
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Definition
Inhibitis Thymidylate synthase (part of THF cycle)
dUMP > dTMP |
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Term
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Definition
Inhibits DHFR (part of THF cycle)
dUMP > dTMP |
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Term
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Definition
Inhibits bacterial DHFR (part of the THF cycle)
dUMP > dTMP |
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Term
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Definition
Inability to convert orotic acid to UMP because of defect in UMP synthase
Autosomal recessive
Inc orotic acid in the urine, NO hyperammonemia (OTC def)
Megaloblastic anemia (not better with b12 admin) , FTT
Tx: oral uridine administration |
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Term
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Definition
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Term
| Adenosine deaminase deficiency |
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Definition
Excess ATP and dATP cause feedback inhibition of ribonucleotide reductase
This prevents DNA synthesis and Drops lymphocyte count
*major cause of SCID
Autosomal recessive |
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Term
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Definition
Absence of HGPRT, which normally converts hypoxanthine to IMP, and guanine to GMP
Results in excess uric acid production and de novo purine synthesis (via Xanthine oxidase) |
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Term
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Definition
| unwinds DNA at replication fork |
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Term
| Single stranded binding proteins |
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Definition
| Prevents strand from reannealing |
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Term
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Definition
Creates nick in the helix to relieve supercoils created during replication
*FQs inhibit DNA gyrase (topoisomerase 2) |
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Term
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Definition
| Makes an RNA primer on which the DNA polymerase 2 can initiate replication |
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Term
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Definition
Prokaryotic only
Elongates leading strand by adding to the 3' end
Elongates lagging strand until it reaches primer of preceding fragment
3'-5' Exonuclease does proof reading of the strands |
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Term
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Definition
| Degrades RNA primer, replaces it with DNA |
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Term
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Definition
Catalyzes the formation of phosphodiesterase bond within a strand of dsDNA
*joins okazaki fragments |
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Term
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Definition
| Enzyme adds DNA to 3' ends of chromosomes to avoid loss of genetic material with every duplications |
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Term
| Nonhomologous end joining |
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Definition
Mutated in ataxia telangiectasia
Cant repair ds breaks in DNA |
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Term
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Definition
DNA and RNA are synthesized 5'-3'
mRNA is read 5'-3'
Protein synth is N > C termins
Remember that the 5' of the incoming nucleotide bears the triphosphate
Triphosphate bond is the target of the 3' hydroxyl attack |
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Term
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Definition
AUG
Codes for methionine in eukaryotes
Codes for f-methionine in prokaryotes |
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Definition
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Term
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Definition
Where RNA polymerase and other transcription factors bind to DNA upstream from the gene locus (AT rich region upstream with TATA and CAAT boxes)
*Promoter mutation results in dramatic decr in amount of gene transcribed |
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Term
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Definition
| Stretch of DNA that alters gene expression by binding transcription factors |
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Term
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Definition
| Site where negative regulators bind |
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Term
| Eukaryotic RNA polymerases |
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Definition
1: rRNA
2: mRNA
3: tRNA
No proofreading abilities, but can initiate chains. RNA pol 2 opens DNA at promoter site
*RNApol2 inhibited by a-amantin (mushrooms) > leads to severe hepatotoxicity |
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Term
| Prokaryotic RNA polymerase |
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Definition
| one RNA polymerase makes all the kind of RNA |
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Term
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Definition
hnRNA destined for translation is called pre-mRNA.
*Processing occurs in the nucleus
Capping of 5' end (addition of 7-methylguanosine cap)
Polyadenylation of 3' end (`200)
Splicing out of introns
Only processed RNA is transferred out the of nucleus |
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Term
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Definition
Primary transcript combines with snRNPs to form a spliceosome
Lariat shaped (looped) intermediate is formed
Lariat is released to remove intron precisely and join two exons |
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Term
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Definition
| Exons contain the genetic information coding for proteins |
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Term
| Regulation of transcription |
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Definition
TFs must bind promoter region 25 nts upstream (Hogness box)
Operator region bonds repressor to block transcription or releases to initiate transcription
Enhance and repressor regions alter the rate of transcription |
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Term
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Definition
Cloverleaf form
Anticodon end is opposite 3' aminoacyl end
All tRNA have CCA at 3' end |
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Term
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Definition
Aminoacyl-tRNA-synthetase scrutinizes amino acid before and after it binds to tRNA
If it is deemed incorrect, the bond is hydrolyzed
A mischarged tRNA reads usual codon but inserts wrong amino acid
*Tetracyclines bind the 30S subunit, preventing attachment of aminoacyl-tRNA |
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Term
| Initiation Protein synthesis |
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Definition
Activated by GTP hydrolysis
Initiation factors help assemble the 40S with the initiator tRNA and are released when the subunit is assembled
Eukaryotes: 40S + 60S = 80S
Prokaryotes: 30S + 50S = 70S
ATP = activation (charging)
GTP = gripping and going places |
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Term
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Definition
Aminoacyl-tRNA binds to A site
Ribosomal rRNA (ribozyme) catalyzes the peptide bond formation, transfers the growing polypeptide to amino acid in A site
Ribosome advances 3 NTs toward the 3' end of mRNA moving peptidyl tRNA to P site |
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Term
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Definition
| Stop codon recognized by release factor and completed protein is released from ribosome |
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Term
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Definition
A: incoming aminoacyl-tRNA
P: accommodates growing peptide
E: holds empty tRNA as it exits |
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Term
| Post translational modifications |
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Definition
Trimming- removal of the N or C terminal pro peptides from zymogens to generate mature proteins
Covalent alterations
Proteosomal degredations - attachment of ubiquitin to defective proteins to tag them for breakdown |
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Term
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Definition
| Cyclin dependent kinases; constiutive and inactive |
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Term
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Definition
Regulatory proteins that control cell cycle events
Activate CDKs |
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Term
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Definition
p53 and hypophosphorylated Rb normally inhibit G1-S progression
mutations in these genes results in unrestrained cell division |
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Term
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Definition
Hepatocytes and lymphocytes
Enter G1 when stimulated |
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Term
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Definition
Synthesis of secretory proteins and N-linked oligosaccharides addition to many proteins
*nissel bodies (neurons) synthesize enzymes (ChAT - makes Ach) and peptide NTs
Goblet cells and Ab secreting plasma cells have lots of RER |
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Term
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Definition
Unattached to any membrane
Site of synthesis of cytosolic and organellar proteins |
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Term
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Definition
Site of Steroid synthesis (Smooth = Steroid)
Also Detox of drugs and poisons
Liver hepatocytes and adrenal cortex are rich in SER |
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Term
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Definition
Distribution center for proteins and lipids from the ER to the vesicles and plasma membrane
*modifies N-oligosacharides on asparagine
Adds O-oligosaccharides on serene and threonine
Adds M6P to proteins for trafficking lysosomes |
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Term
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Definition
Inherited lysosomal storage disorder; failure of addition of M6P to lysosome proteins
Coarse facial features, clouded corneas, restricted joint movement, high plasma levels of lysosomal enzymes
Often fatal in childhood |
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Term
| Vesicular trafficing proteins |
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Definition
COP1: golgi > golgi (retrograde); golgi > ER
COP2: Golgi > golgi (anterograde); ER > Golgi
Clathrin: trans golgi > lysosomes; PM > endosomes |
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Term
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Definition
| membrane enclosed organelle involved in catabolism of very long fatty acids and amino acids |
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Term
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Definition
| Barrel shaped protein complex that degrades damaged or unnecessary proteins tagged for destruction with ubiquitin |
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Term
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Definition
Helical array of dimers of a and B tubulin
Each dimer has two GTP bound
Within flagella, cilia and mitotic spindles
Also involved in axoplasmic transport in neurons |
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Term
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Definition
| Retrograde to microtubule |
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Term
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Definition
| Anterograde to microtubule |
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Term
| Drugs that act on microtubules |
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Definition
| Mebendazole, Griseofulvin, Vincristine, Paclitaxel, Colchicine |
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Term
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Definition
Mutation in the LYST (lysosomal trafficking regulator gene)
Necessary for microtubule dependent sorting of endosomal proteins into late endosomes
*recurrent pyogenic infections, partial albinism, peripheral neuropathy |
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Term
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Definition
9+2 arrangement of microtubules
Axonemal dynein- ATPase links peripheral 9 doublets and causes bending of cilium |
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Term
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Definition
Immotile cilia due to a dynein arm defect
Results in male infertility and dec female fertility, bronchiectasis, and recurrent sinusitis
*assoc with sinus invertus |
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Term
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Definition
| microvilli, muslce contraction, cytokinesis, adherens junctions |
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Term
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Definition
| Cilia, flagella, mitotic spindle, centrioles, axonal trafficking |
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Term
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Definition
| Vimentin, desmin, cytokeratin, lamins, GFAP, neurofilaments |
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Term
| Stains for intermediate filaments |
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Definition
Vimentin - CT
Desmin - Muslce
Cytokeratn - Epithelial cells
GFAP - neuroglia
Neurofilaments - neurons |
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Term
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Definition
Located in the PM with ATP site on cytosolic side
For 1 ATP: 3Na out, 2K in
*Oubain inhibits by binding the K site
*Cardiac Glycosides directly inhibit leading to inc Ca inside via indirect inhibition of the Ca/Na exchanger |
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Term
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Definition
Most abundant protein in the body
Extensively modified by post translational modification |
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Term
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Definition
"Strong collagen"
Most common - 90%
Bone, Skin, Tendon, dentin, fascia, cornea, late wound repair
*Defective in Osteogenesis imperfecta |
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Term
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Definition
"Slippery collagen"
Cartilage, vitreous body, nucleus pulposus |
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Term
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Definition
"Bloody cartilage"
Reticulin, skin, blood vessels, uterus, fetal tissue, granulation tissue
*defective in Ehlers Danlos |
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Term
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Definition
"BM"
Basement membrane or basal lamina
*defective in Alport syndrome |
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Term
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Definition
In fibroblasts: synthesis, hydroxylation, glycosylation, and exocytosis
Outside fibroblasts: proteolytic processing and cross linking |
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Term
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Definition
Occurs in the RER
Translation of alpha chains (preprocollagen)
Usually Gly-X-Y (proline and lysine) |
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Term
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Definition
Happens in the ER
Hydroxylation of specific lysine and proline reidues
Requires vitamin C |
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Term
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Definition
ER
Glycosylation of pro-a-chain hydroxylysine and formation of pro collagen via hydrogen and disulfide bonds
Triple helix of 3 a chains
*OI- trouble forming the triple helix |
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Term
| Collagen Proteolytic processing |
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Definition
| Cleavage of disulfide rich terminal transforming it into tropocollagen |
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Term
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Definition
Reinforcement by covalent lysine-hydroxylysine to make collagen fibrils
*ED- problems with cross linking |
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Term
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Definition
Brittle bone disease
Autosomal dominant, abnormal type 1 collagen
*blue sclera, hearing loss, dental imperfections |
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Term
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Definition
Faulty type 3 collagen synthesis (cross linking)
Hyperextensible skin, tendency to bleed, hyper mobile joints
Berry aneruysm, organ rupture |
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Term
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Definition
Abnormal type 4 collagen, X linked recessive
Progressive hereditary deafness, and nephritis. Can also have ocular disturbances |
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Term
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Definition
Stretchy protein rich in protein and glycine
Tropoelastin with a fibrillin scaffolding
Broken down by elastase which is normally inhibited by a1-antitrypsin |
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Term
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Definition
| Defect in fibrillin, leads to hyper elastic joints and AAA |
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Term
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Definition
| Procedure to amplify a desired fragment of DNA |
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Term
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Definition
Southern: DNA, with DNA probe
Northern: RNA with DNA probe
Western: Protein with Ab probe
SW: DNA binding proteins with oligonucleotide probe |
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Term
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Definition
| Used to profile gene expression levels |
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Term
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Definition
Antigen AB reactivity
Indirect- test antigen to see if a spec Ab is present in pt blood
Direct - test Ab to see if antigen is present in pt blood |
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Term
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Definition
| No flourescence - gene has been deleted |
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