cells

Question 1

cell fractionation

Answer 1

the process where cells are broken up and different organelles are separated out

Question 2

before cell fractionation

Answer 2

tissue places in cold buffered solution same water potential as tissue

Question 3

buffered solution tissue placed in feature

Answer 3

cold- less enzyme activity that could break down organelles
same water potential - prevent organelles bursting or shrinking from osmotic gain or loss
buffered - pH does not fluctuate no organelle structure altered

Question 4

homogenisation

Answer 4

cells broken up by homogeniser releasing organelles

Question 5

ultracentrifugation

Answer 5

fragments in filtered homogenise separated in centrifuge

Question 6

ultracentrifugation in animal cells process

Answer 6

filtrate tube placed in centrifuge and spun at slow speed

heaviest organelles forced to bottom forming thin sediment

fluid at top of tube removed leaving sediment

supernatant transferred to another tube and spun in centrifuge at faster speed

next heaviest at bottom
sedimented and separated increasing speed

Question 7

electron microscope

Answer 7

electron beam short wavelength so microscope resolves objects well

Question 8

TEM

Answer 8

electron gun w beam of electrons focused onto specimen

Question 9

limitations of TEM and SEM

Answer 9

no living organisms
no colour
specimen thin to penetrate -
slow and complicated

Question 10

SEM

Answer 10

beam of electrons into surface of specimen from above

Question 11

eyepiece graticule

Answer 11

measure size of objects with light microscope
glass disc placed in eyepiece

Question 12

stage micrometer

Answer 12

slide to calibrate eyepiece gracticule

Question 13

nuclear enevelope

Answer 13

double membrane surrounding nucleus w ribosomes on surface

Question 14

nuclear pores

Answer 14

passage of large molecules out of nucleus

Question 15

necleoplasm

Answer 15

jelly

Question 16

nucleolus

Answer 16

rRNA, synthesis of ribosomes

Question 17

mitochondria- cristal

Answer 17

extensions of inner membrane
attach enzymes and other proteins for respiration

Question 18

mitochondria- matrix

Answer 18

protein lipids ribosomes DNA
mitochondria control protein production
enzymes for respiration

Question 19

chloroplast envelope

Answer 19

what enters and leaves chloroplast

Question 20

chloroplasts- grana

Answer 20

grana - 1st stage photosynthesis
have thylakoids with chlorophyll

Question 21

stroma- chloroplast

Answer 21

2nd stage photosynthesis

Question 22

SER

Answer 22

synthesis and transport of lipids and carbs
no ribosomes on surface

Question 23

RER

Answer 23

transport and synthesis of proteins
ribosomes in outer surface
large SA for synthesis of proteins and glycoproteins

Question 24

golgi apparatus

Answer 24

stack of membranes that make up cisternae w vesicles

add carb to proteins- glycoproteins
secretory enzymes produced
secrete carbs
transport modify store lipids
form lysozymes

Question 25

lysosomes

Answer 25

formed when vesicles produced by golgi apparatus contain enzymes contain lysozymes - hydrolyse cell walls of some bacteria break down cells after died hydrolyse material ingested by phagocytic cells release enzymes to destroy material around cell

Question 26

cell wall

Answer 26

strength to prevent cell bursting

Question 27

vacuoles

Answer 27

keep cells turgid sugars and AA temporary food store