Biology 1 Flashcards
post-translational modification
- starts in RER (disulfide bonds + glycoslylation)
- continues in golgi
smooth ER
lipid synthesis + modification
golgi
- finish post-translational modification
- excrete vesicles bound for membrane, ER, etc
- cellular post office
mitochondria
lysosome
pH = 5, digest cell parts, apoptosis, form by budding from golgi
peroxisomes
self replicate, detoxify chemicals, lipid metabolism
spindle apparatus
microtubules
actin
protein monomer that polymerizes to form microfilament (forms thin portion of sarcomere)
intermediate filament
smaller than microtubules, larger than microfilament
microtubules
mitotic spindle, cilia/flagella, transport
microfilaments
movement (cleavage furrow)
cilia in humans
lungs, ependymal cells (nervous system -> glia), fallopian tubes
sperm
flagella, made of tubulin
facilitated diffusion
no ATP required → use of protein channel (osmosis)
tight junction
water proof
tight epithelium → lining of bladder
gap junction
tunnels between cells allowing exchange → muscle cells + direct neuronal coupling
adheren junction
strong mechanical attachments → epithelium between cardiac muscle cells
desmosomes
strongest → weld cells together (not waterproof) → tissues subject to stress → dermis
g-protein
cell cycle
nondisjunction
occurs in anaphase 1 or 2
DNA replication
3’ → 5’
*** uses RNA primer not promoter
each time DNA replicates, new strand is slightly shorter than the parent strand, DNA polymerase requires an existing 3’ OH to add their first nucleotide → RNA primers are used and then removed
mismatch repair
enzymes scan, locate, excise + replace mismatched pairs in newly copied DNA
base excision repair
base portion removed by DNA glycosylase, other enzymes remove backbone, DNA polymerase + ligase replace
nucleotide excision repair
excision of oglionucleotides that includes several bases on either side of error, DNA polymerase + ligase replace
gel
used to separate molecules by size
charged field across gel
RNA vs DNA
- RNA has 2’ OH
- RNA normally single stranded
- RNA contains U instead of T
- RNA exits nucleus into cytoplasm (DNA always stays inside nucleus)
template strand
anti-coding/anti-sense → transcribed
coding
sense → not transcribed
***same as RNA strand (except T → U)
transcription
RNA polymerase binds to promoter on 3’ end of template strand with aid of transcription factors
termination factors cause the release of mRNA transcript
post-transcriptional processing
occurs in nucleus → introns spliced out, poly-A tail added to 3’, 5’ cap added
*** exons exit nucleus, introns stay in nucleus
lac operon
inducible operon → usually turned off (repressed)
translation
- occurs in cytoplasm + RER
- small subunit attaches to 5’ end of mRNA with help of initiation factors → scans mRNA until it reaches start codon (AUG)
- tRNA attaches to start codon → causes large subunit to bind
- elongation
- termination: reaches stop codon (UAA, UGA, UAG) → release factor binds → dissociation of ribosome
law of segregation
one allele ends up in one gamete → random which “parent’s” allele ends up in which gamete
law of independent assortment
the allele one gamete receives for one gene doesn’t influence the allele received for another gene
*** meiosis 1
gram negative bacteria
stain pink, relatively thin cell wall, don’t form endospores, contain two cell membranes: one inside + one outside cell wall
gram positive bacteria
stain purple, very thick cell wall, form endospores (dormant), single membrane (inside cell wall)
tubulin
globular protein that polymerizes to form microtubules
α-tubulin + β-tubulin = protofilament
13 protofilaments = 1 microtubule
9 doublets + 1 doublet of microtubule = flagella
