Exam 2 Part 6

Question 1

In addition to DNA rep, cell division involves…

Answer 1

organelle division which sort themselves into daughter cells

membranes from nucleus, ER, and Golgi break down and then reform

Question 2

Transport proper proteins to newly formed organelles

Answer 2

use an existing protein to move

-signalling

Question 3

transport mechanisms

Answer 3

• transport through nuclear pores
• transport across membranes
• transport by vesicle

Question 4

how does a protein know where to go?

Answer 4

signal sequences - particular characteristic of the amino acids helps

Question 5

transport necessities

Answer 5

• need to mark/ID the protein

- mark its destination

Question 6

How do we know where a specific signal sequence goes?

Answer 6

need to see things, so add florcesent mark to both the sequence and the predicted organelle

Question 7

what goes into the nuclear envelope?

Answer 7

histones, DNA pol, helicase, topoisomerase, transcription machinery (regulatory), cytoskeleton

Question 8

what goes out of the nuclear pore?

Answer 8

mRNA, ribozymes, ribosomes (assembled in nucleus)

Question 9

histones

Answer 9

needed during replication, can diffuse through the smaller nuclear pores

Question 10

nuclear lamina

Answer 10

filaments, hold and support the nuclear envelope

Question 11

nuclear envelope

Answer 11

continuous with the ER membrane, has pores

Question 12

nuclear pores

Answer 12

big cages, docking system
how big molecules get into the nucleus
small enough for selectivity, big enough for some passivity

Question 13

Ran-GDP

Answer 13

binds to nuclear protein and receptor to allow the protein into the nucleus.
GTP will replace GDP in the nucleus

Question 14

Ran-GTP

Answer 14

GTP replaces GDP on Ran-GDP, which kicks off the cargo protein (STAYS WITH RECEPTOR)
Passes back out of the nuclear membrane with the receptor
hydrolyzes its bound GTP and GDP disassociates from receptor

Question 15

G-proteins

Answer 15

bind to guanine nucleotides (GDP, GTP)
hydrolyze GDP to GTP
act like “switches” by ossilating bt 2 guanine binding

Question 16

transport into nuclear envelope

Answer 16

Ran-GDP binds to protein, with binds to receptor. Complex changes shape and enables it to enter membrane
Ran-GTP replaces Ran-GDP and kicks off protein
Ran-GTP and receptor travel back across membrane
Ran hydrolyzes its GTP and Ran-GDP dissociates from receptor

Question 17

transport into organelles

Answer 17

either can go into the lumen because that’s where it’s job is or into the membrane for transport elsewhere (control when and where)

Question 18

import into ER

Answer 18

ribosomes are brought near the ER membrane so that the protein can be threaded through while synthesis occurs

Question 19

SRP

Answer 19

signal recognition particle

binds to proteins that will take it to the membrane

Question 20

hydrophobic start-transfer sequence

Answer 20

hydrophobic so that it will embed into the membrane

Question 21

signal peptidase

Answer 21

cuts off the start-transfer sequence if it is at the N-terminus

Question 22

stop-transfer sequence

Answer 22

enters channel and stops the transfer of the protein into the membrane – for transmembrane proteins

Question 23

chaperone proteins

Answer 23

regulate the proper folding of proteins in the ER

Question 24

mitochondrial transport

Answer 24

protein created, folded in cytosol, then taken to mitochondira, unfolded as it binds to receptor, transported across both membranes, and then folded again

Question 25

vesicular transport

Answer 25

for proper transport, only proteins meant to be transported will bind to cargo that will package it
package needs destination markers

Question 26

clatharin

Answer 26

serves as the vesicle coat

honeycomb structure

Question 27

dynamin

Answer 27

pinches off the vesicle

Question 28

adaptin

Answer 28

linkes the receptor to the coat

cue for when to make the vesicle

Question 29

cargo receptor

Answer 29

binds target molecule

Question 30

v-SNARE

Answer 30

vesicle snare, will bind to the t-SNARE to assist in docking

Question 31

t-SNARE

Answer 31

transport snare, will bind to v-SNARE to assist in docking

Question 32

Rab

Answer 32

G-protein

protein director, brings cargo to the right destination

Question 33

tethering protein

Answer 33

on membrane - binds to Rab to bring vesicle to right place

Question 34

trans Golgi

Answer 34

faces membrane - things leaving cell go out this side

Question 35

cis Golgi

Answer 35

faces cell contents - things going to other parts of cell go out this side

Question 36

fates of endocytosis

Answer 36

• recycling
• degradation
• transcytosis