Biology 1

Question 1

post-translational modification

Answer 1

• starts in RER (disulfide bonds + glycoslylation)
• continues in golgi

Question 2

smooth ER

Answer 2

lipid synthesis + modification

Question 3

golgi

Answer 3

• finish post-translational modification
• excrete vesicles bound for membrane, ER, etc
• cellular post office

Question 4

mitochondria

Answer 4

Question 5

lysosome

Answer 5

pH = 5, digest cell parts, apoptosis, form by budding from golgi

Question 6

peroxisomes

Answer 6

self replicate, detoxify chemicals, lipid metabolism

Question 7

spindle apparatus

Answer 7

microtubules

Question 8

actin

Answer 8

protein monomer that polymerizes to form microfilament (forms thin portion of sarcomere)

Question 9

intermediate filament

Answer 9

smaller than microtubules, larger than microfilament

Question 10

microtubules

Answer 10

mitotic spindle, cilia/flagella, transport

Question 11

microfilaments

Answer 11

movement (cleavage furrow)

Question 12

cilia in humans

Answer 12

lungs, ependymal cells (nervous system -> glia), fallopian tubes

Question 13

sperm

Answer 13

flagella, made of tubulin

Question 14

facilitated diffusion

Answer 14

no ATP required → use of protein channel (osmosis)

Question 15

tight junction

Answer 15

water proof

tight epithelium → lining of bladder

Question 16

gap junction

Answer 16

tunnels between cells allowing exchange → muscle cells + direct neuronal coupling

Question 17

adheren junction

Answer 17

strong mechanical attachments → epithelium between cardiac muscle cells

Question 18

desmosomes

Answer 18

strongest → weld cells together (not waterproof) → tissues subject to stress → dermis

Question 19

g-protein

Answer 19

Question 20

cell cycle

Answer 20

Question 21

nondisjunction

Answer 21

occurs in anaphase 1 or 2

Question 22

DNA replication

Answer 22

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

Question 23

mismatch repair

Answer 23

enzymes scan, locate, excise + replace mismatched pairs in newly copied DNA

Question 24

base excision repair

Answer 24

base portion removed by DNA glycosylase, other enzymes remove backbone, DNA polymerase + ligase replace

Question 25

nucleotide excision repair

Answer 25

excision of oglionucleotides that includes several bases on either side of error, DNA polymerase + ligase replace

Question 26

gel

Answer 26

used to separate molecules by size charged field across gel

Question 27

RNA vs DNA

Answer 27

* RNA has 2' OH * RNA normally single stranded * RNA contains U instead of T * RNA exits nucleus into cytoplasm (DNA always stays inside nucleus)

Question 28

template strand

Answer 28

anti-coding/anti-sense → transcribed

Question 29

coding

Answer 29

sense → not transcribed \*\*\*same as RNA strand (except T → U)

Question 30

transcription

Answer 30

RNA polymerase binds to promoter on 3' end of template strand with aid of transcription factors termination factors cause the release of mRNA transcript

Question 31

post-transcriptional processing

Answer 31

occurs in nucleus → introns spliced out, poly-A tail added to 3', 5' cap added \*\*\* exons exit nucleus, introns stay in nucleus

Question 32

lac operon

Answer 32

inducible operon → usually turned off (repressed)

Question 33

translation

Answer 33

* 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

Question 34

law of segregation

Answer 34

one allele ends up in one gamete → random which "parent's" allele ends up in which gamete

Question 35

law of independent assortment

Answer 35

the allele one gamete receives for one gene doesn't influence the allele received for another gene \*\*\* meiosis 1

Question 36

gram negative bacteria

Answer 36

stain pink, relatively thin cell wall, don't form endospores, contain two cell membranes: one inside + one outside cell wall

Question 37

gram positive bacteria

Answer 37

stain purple, very thick cell wall, form endospores (dormant), single membrane (inside cell wall)

Question 38

tubulin

Answer 38

globular protein that polymerizes to form microtubules α-tubulin + β-tubulin = protofilament 13 protofilaments = 1 microtubule 9 doublets + 1 doublet of microtubule = flagella