Topic B

Question 1

some plant cells have the ___ squished against the side of the cell by the central vacuole

Answer 1

nucleus

Question 2

describe nuclear pores

Answer 2

are numerous (~3000 per mammalian nucleus) and large (120nm diameter)

Question 3

how do nucleotides enter the nuclear pores?

Answer 3

through diffusion

Question 4

what is a test of discovery experiment?

Answer 4

based upon observing a process

Question 5

what is a test of necessity experiment?

Answer 5

observing if the process occurs when something is removed

Question 6

what is a test of sufficiency experiment?

Answer 6

observing if the process occurs when something is added

Question 7

NLS

Answer 7

nuclear localization signal

Question 8

what is required for nuclear import?

Answer 8

nuclear localization signal (NLS) and importin proteins

Question 9

what do importin proteins associate with?

Answer 9

associate with the nuclear localization signal (NLS) and nuclear pore

Question 10

what is required for nuclear export?

Answer 10

nuclear export signal (NES) and exportin proteins

Question 11

what do exportin proteins associate with?

Answer 11

associate with NES (or RNA directly) and nuclear pore

Question 12

importin and exportin’s affinity for the nuclear pore is?

Answer 12

always high

Question 13

importin’s affinity for cargo is?

Answer 13

high in cytosol, low in nucleus

Question 14

exportin’s affinity for cargo is?

Answer 14

low in cytosol, high in nucleus

Question 15

ran-GTP has an affinity for?

Answer 15

importins and exportins

Question 16

where is ran-GDP found?

Answer 16

the cytosol

Question 17

where is ran-GTP found?

Answer 17

the nucleus

Question 18

ran ____ importins and _____ exportins in the nucleus (load or unload)

Answer 18

unloads…loads

Question 19

chromatin

Answer 19

complex of DNA, histones and non-histones found in the nucleus of a euk cell. Material that makes up chromosomes

Question 20

outer nuclear envelope

Answer 20

surrounds the inner nuclear membrane. Is continuous with the inner nuclear membrane and the membrane of the endoplasmic reticulum

Question 21

nuclear lamina

Answer 21

fibrous meshwork of proteins on the inner surface of the inner nuclear membrane. Made of intermediate filaments formed from nuclear lamins

Question 22

nuclear pore complex (NPC)

Answer 22

large multiprotein structure forming the nuclear pore through the nuclear envelope that allows selected molecules to move between nucleus and cytoplasm

Question 23

what do enzymes in the ER synthesize?

Answer 23

phospholipids, glycolipids and cholesterol

Question 24

what mechanism is used to deliver membrane lipids to the ER and nuclear envelope?

Answer 24

lateral diffusion

Question 25

what mechanism is used to deliver phospholipids to the ER and nuclear envelope?

Answer 25

lateral diffusion

Question 26

what mechanism is used to deliver phospholipids to the rest of the endomembrane system?

Answer 26

transport vesicles

Question 27

what mechanism is used to deliver phospholipids to semi-autonomous organelles?

Answer 27

phospholipid exchange proteins

Question 28

what mechanism is used to deliver phospholipids to the chloroplasts?

Answer 28

phospholipid exchange proteins (same as mitochondria)

Question 29

where are proteins made?

Answer 29

some in free ribosomes, some in the ER

Question 30

what mechanism is used to create proteins destined for the cytosol?

Answer 30

free ribosomes

Question 31

what mechanisms are used to create and deliver proteins to the mitochondrion, peroxisomes and the nucleus?

Answer 31

free ribosomes and then import (has cell signals)

Question 32

how are proteins exported?

Answer 32

ribosomes at ER and then vesicles

Question 33

what mechanisms are used to create and deliver proteins to the nuclear envelope and ER?

Answer 33

ribosomes at ER and then lateral diffusion

Question 34

what mechanisms are used to create and deliver proteins to the lysosomes, golgi and plasma membrane?

Answer 34

ribosomes at ER and then vesicles

Question 35

what mechanisms are used to create and deliver proteins to the chloroplasts?

Answer 35

free ribosomes and then import (same as mitochondria)

Question 36

what are the functions of a vesicle?

Answer 36

1. move material within endomembrane system 2. exocytosis 3. endocytosis

Question 37

receptor mediated endocytosis

Answer 37

importing whole proteins

Question 38

how do vesicles form?

Answer 38

cargo receptors -> clathrin (and other coat proteins) -> adaptin ->dynamin -> remove coat proteins

Question 39

how many heme groups does hemoglobin have?

Answer 39

four

Question 40

where is iron located in humans?

Answer 40

hemoglobin (in red blood cells)

Question 41

what is the iron delivery path?

Answer 41

iron goes to the intestine cell -> blood -> future red blood cells

Question 42

transferrin proteins

Answer 42

synthesized in liver cells, carry iron in blood

Question 43

how does transferrin carry iron into future RBCs?

Answer 43

receptor mediated endocytosis

Question 44

how do vesicles move?

Answer 44

microtubules, kinesin, dynein

Question 45

kinesin

Answer 45

plus-end directed microtubule protein

Question 46

dynein

Answer 46

minus-end directed microtubule motor protein

Question 47

exocytosis uses ____; endocytosis uses _____ (which MT motor protein)

Answer 47

kinesins...dyneins

Question 48

ER -> Golgi uses____ (which MT motor protein)

Answer 48

dyneins

Question 49

how do vesicles fuse with their target membrane?

Answer 49

when SNAREs pull together

Question 50

which organelles do vesicles move between?

Answer 50

ER, golgi, plasma membrane, lysosomes (endomembrane system)

Question 51

tSNARE

Answer 51

target SNARE (on plasma membrane)

Question 52

vSNARE

Answer 52

vesicle SNARE

Question 53

dynamin

Answer 53

involved in vesicle formation, binds to clathrin-coated vesicle in the process of budding from the membrane

Question 54

cargo

Answer 54

membrane components and soluble molecules carried by transport vesicles

Question 55

adaptin

Answer 55

connect clathrins to cargo receptors (regulated like Ran)

Question 56

function of cis side of golgi apparatus

Answer 56

"receiving"

Question 57

function of trans side of golgi apparatus

Answer 57

"shipping"

Question 58

amount of golgi in an animal cell

Answer 58

single large stack

Question 59

amount of golgi in a plant cell

Answer 59

many little stacks

Question 60

golgi apparatus function

Answer 60

modify and distribute proteins and membrane lipids made in ER

Question 61

constitutive exocytosis

Answer 61

default pathway (eg. goblet cells, cell growth)

Question 62

regulated exocytosis

Answer 62

secretes products rapidly on demand (eg. export of insulin)

Question 63

what signal is given to future lysosome enzymes in the golgi?

Answer 63

M6P signal

Question 64

M6P Receptor's affinity for cargo is?

Answer 64

high in Golgi (pH 6.5) | low in lysosome (pH <6.0)

Question 65

vesicles formed by receptor mediated endocytosis and phagocytosis fuse with what?

Answer 65

lysosomes

Question 66

how do endosomes become lysosomes?

Answer 66

when pH drops (pH 6.0 to 5.0), done by ATP powered proton pumps