endocytosis and autophagy

Question 1

COP1 and COP2 proteins assemble on what side of the donor compartment

Answer 1

they assemble on the cytosolic surface of the donor compartment membranes at sites where budding takes place

Question 2

what directs vesicles to other parts of the cell

Answer 2

clathrin-coated vesicles move from TGN to other vesicles

Question 3

cis-____-trans

Answer 3

cis-med-trans

Question 4

what are lysosomes

Answer 4

digestive organelles

Question 5

what is the internal ph of lysosomes

Answer 5

4.6 because of H+-ATPase

Question 6

how do lysosomes maintain their acidic pH

Answer 6

protein pumps

Question 7

autophagy

Answer 7

organelle turnover

• destruction and recycling of organelles
• lysosomes sure with ER-derived autophagic vesicle (forms auto lysosome)

Question 8

contents are ______ digested and released through _____

Answer 8

contents are enzymatically digested and released through exocytosis

Question 9

why do cells degrade material

Answer 9

• to recycle plasma membrane components and extracellular material
• to destroy pathogens (bacteria/viruses)

Question 10

what is a tonoplast

Answer 10

vacuolar membrane

-contains active transport system that generates high interior ion concentration

Question 11

what is phalloidin

Answer 11

binds actin

Question 12

function of plant vacuoles

Answer 12

• intracellular digestion
• storage
• mechanical support (turgor pressure)

Question 13

describe intracellular digestion in plant vacuoles

Answer 13

low pH (acid hydrolyses)

Question 14

describe the storage in plant vacuoles

Answer 14

• stores solutes and macromolecules
• chemical storage (bc they don’t have an excretory system)
• isolates toxic compounds
• holds pigments

Question 15

describe the mechanical support provided by plant vacuoles

Answer 15

• gives rigidity to plant (supports soft tissues)

- stretches cell wall during growth

Question 16

describe the cytoskeleton of plants

Answer 16

dynamic network of interconnected filaments and tubes that extend throughout the cytosol (and some organelles)

• spacial organization
• contractility and motility

Question 17

order the three types of microtubules in order of smallest to largest

Answer 17

microfillaments

Question 18

describe microtubules

Answer 18

• largest cytoskeletal element

- polymer of proteins (alpha-tubulin and beta-tubulin)

Question 19

what are the two major types of microtubules

Answer 19

1) axonemal

2) Cytoplasmic

Question 20

describe axonemal microtubules

Answer 20

• highly organized and stable

- involved in cell movement (cilia, flagella)

Question 21

describe cytoplasmic microtubules

Answer 21

• loosely organized, very dynamic

- located in cytosol

Question 22

where are cytopplasmic microtubules located

Answer 22

in cytosol