exam 3

kinesins

move cargo to plus end

dynein

moves cargo to minus end

colchicine and vinblastine

bind tubulin dimers, block microtubule formation

taxol

stabilizes microtubules, cancer treatment

axoneme

9+2 structure in cilia/flagella

dynein arms

slide for bending motion

nexin

links doublets, prevents sliding apart

cilia

move fluid over cell surface

flagella

propel whole cell

actin

polarized filament, barbed +, pointed -

treadmilling

add at +, lose at -

cytochalasin D

blocks barbed end, stops elongation

phalloidin

binds/stabilizes actin, mushroom toxin

latrunculin

binds G-actin, blocks polymerization

cytokinesis

actin ring splits cell

myosin II

muscle contraction, sliding filaments

myosin V

vesicle transport, hand-over-hand

myosin Va

pigment transport, Griscelli syndrome

myosin VI

moves to - end, stereocilia function

microtubules

form spindle apparatus

actin

aids cytokinesis

chromosome discovery

Walter Fleming

rosalind franklin

x-ray of DNA helix

watson and crick

double helix, H bonds between bases

topoisomerases

control DNA supercoiling

topoisomerase I

cuts 1 strand

topoisomerase II

cuts 2 strands, untangles

polytene chromosome

many DNA copies, no division

catenation

linked circular DNA

decatenation

untangling by topo II

etoposide and doxorubicin

inhibit topoisomerase, cancer drugs

higher GC

higher Tm

melt temp

half DNA denatured

satellite DNA

5-500bp, separated by density

minisatellite DNA

10-100bp, DNA fingerprinting

microsatellite DNA

1-5bp, used in genetic disorders

repeated sequences

20-80% of genome

coding DNA

rRNA, histones

non-coding DNA

SINEs, LINEs

non-repeated sequences

inheritance, specific loci

single copy genes

encode structural proteins

DNA fingerprinting

uses VNTRs, gel electrophoresis

FISH

fluorescent probes for DNA location

stop codons

UAA UAG UGA

Huntington’s

CAG repeat expansion in HTT

Fragile X

CGG repeat in FMR1 gene

whole genome duplication

polyploidy, diversity

Susumu Ohno

2R hypothesis

transposons

jumping genes

cut and paste

uses transposase

copy and paste

retrotransposons

miescher

first isolated nuclein

Griffith et al

proved DNA = genetic material

Beadle-Tatum

one gene one enzyme

transcription

DNA to mRNA by RNA pol

translation

mRNA to protein

tRNA

carries amino acids

mRNA

DNA code to ribosome

transcription steps

unzip DNA, match bases, RNA pol builds

moves 3’ to 5’

RNA made 5’ to 3’

prok RNA polymerase

has core enzyme

sigma factor

promoter recognition

sigma dissociates

after 10 nt, elongation continues

Rho

transcription termination

RNA pol II

transcribes mRNA, needs GTFs

TATA box

promoter for RNA pol II

group II introns

self-splicing

pseudo-uridine in rRNA

adds stability

tRNA in translation

brings AA, reads codons

ribosome reads

mRNA 5’ to 3’

euk ribosome subunits

made in nucleolus

siRNA

targets mRNA, gene silencing

miRNA

binds 3' UTR, represses genes

RNAi

used in cancer therapy

siRNA uses

hepatitis, macular degeneration

CRISPR-Cas9

cuts viral DNA, guided by RN