How are cells studied?

Question 1

where are unicellular eukaryote cultures grown

Answer 1

in YEPD liquid media or YEPD agar plates

Question 2

YEPD

Answer 2

Yeast Extract + Peptone (amino acids) + Dextrose (sugar)

Question 3

what can plant and animal cells do in vitro?

Answer 3

live, grow, and multiply

Question 4

in vitro

Answer 4

outside the body

Question 5

what are multicellular eukaryotes fed in vitro

Answer 5

Eagle’s minimal essential media (MEM)

Question 6

what is MEM composed of?

Answer 6

1. amino acids (some essential)
2. vitamins
3. salts
4. glucose
5. penicillin (antibiotic)
6. serum (growth factor proteins)

Question 7

serum

Answer 7

growth factor proteins that give cells permission to reproduce

Question 8

essential amino acids

Answer 8

AAs not produced in the body

Question 9

3 popular cell lines

Answer 9

1. PTK1 from kangaroo rat kidney in 1961
2. MDCK from cocker spaniel kidney in 1958
3. HeLa from Henrietta Lacks cancer cells in 1951

Question 10

subcellular fractionation

Answer 10

the isolation and purification of cellular organelles and macromolecules using centrifugation

Question 11

3 steps of subcellular fractionation

Answer 11

1. homogenization
2. isolation
3. purification

Question 12

ultracentrifuge

Answer 12

machine that spins things

Question 13

what is the max spin speed and max force of an ultracentrifuge

Answer 13

100 000 rpm generating 600 000 Gs

Question 14

2 safety precautions of an ultracentrifuge

Answer 14

1. must be refrigerated or it will melt

2. armored chambers contain the rotor in case it breaks

Question 15

homogenization

Answer 15

breaks plasma membrane to release cell contents

Question 16

what does homogenization turn cells into

Answer 16

cell homogenate

Question 17

cell homogenate

Answer 17

the inner contents of a cell

Question 18

4 methods of homogenization

Answer 18

1. break cell with high-frequency sound
2. force cells through a small hole using high pressure
3. use mild detergent to make holes in the membrane
4. shear cells between close-fitting rotating plunger and thick walls of glass

Question 19

how is isolation achieved

Answer 19

differential centrifugation

Question 20

differential centrifugation

Answer 20

method of separating cell components according to whether they sediment or not

Question 21

what do larger and more dense components do in differential centrifugation?

Answer 21

form a pellet

Question 22

what do smaller and less dense components do in differential centrifugation?

Answer 22

form a supernatant

Question 23

low speed centrifugation

Answer 23

1000 Gs for 10 min

Question 24

what does low speed pellet

Answer 24

whole cells, nuclei, cytoskeletons

Question 25

medium speed centrifugation

Answer 25

20 000 Gs for 20 mins

Question 26

what does medium pellet

Answer 26

mitochondria, lysosomes, peroxisomes

Question 27

high speed centrifugation

Answer 27

80 000 Gs for 60 mins

Question 28

what does high speed pellet

Answer 28

microsomes, other small vesicles

Question 29

microsomes

Answer 29

pieces of ER

Question 30

very high speed centrifugation

Answer 30

200 000 Gs for 120 mins

Question 31

what does very high speed centrifugation pellet

Answer 31

ribosomes, viruses, large macromolecules

Question 32

2 different methods of purification

Answer 32

1. velocity centrifugation

2. equilibrium centrifugation

Question 33

2 other names for velocity centrifugation

Answer 33

1. density gradient centrifugation

2. rate zonal centrifugation

Question 34

velocity centrifugation

Answer 34

purifies cell components according to sedimentation rate

Question 35

velocity centrifugation procedure

Answer 35

• fill tube with concentration gradient of sucrose
• fast sedimenting components will fall to the bottom
• collect bands by puncturing the bottom of the tube

Question 36

equilibrium centrifugation procedure

Answer 36

• fill tube with concentration gradient of sucrose

- at equilibrium, components migrate to regions of their own density

Question 37

equilibrium centrifugation

Answer 37

purifies cell components according to buoyant density