exam 1: lecture 4

Question 1

prokaryotic

Answer 1

capsule (sticky sugar +lipids )
cell wall
cell membrane
cytoplasm
ribosomes
nucleoid
circular chromosome
flagella

Question 2

capsule (slime layer) function

Answer 2

1) food storage
2) to help bacteria stick to surfaces
3) to make bacteria more pathogenic and avoid immune sys
4) keep the bacteria from drying out

Question 3

what determines the shape of bacteria

Answer 3

cell wall-protects bacteria from rapid chnges in the osmotic environment

Question 4

what organelles can be found in eukaryotic cells

Answer 4

a nucleus
endomembrane sys
cytoskeleton
lysosome
mitochondria

Question 5

structures that both eukaryotes and prokaryotes have

Answer 5

ribosomes
cytoplasm
cell membrane
DNA ( chromosome differ)
cell walls
flagella

Question 6

overton

Answer 6

lipid nature of membrane
-suggests that it’s lipid letting h2o thru (root hair)

Question 7

langmuir

Answer 7

lipid monolayer where it is amphipathic
water and benzene

Question 8

gorter and grendel

Answer 8

lipid bilayer
-found twice as much lipids than langmuir said-therefore not a single layer but BILAYER

Question 9

davson and danielli

Answer 9

liquid bilayer plus protein lamellae (regulting whats goes in/out

Question 10

robertson

Answer 10

unit membrane
-artifact: was not able to reproduce it again

Question 11

singer and nicolson

Answer 11

fluid mosaic model-orgainzation of protein, lipidsl chlorestorols for membranes fluidity

Question 12

unwin and henderson

Answer 12

membrane protein structure- transmemnrane proteins where the proteins extends ou to both side of bilayer

Question 13

saturated lipids

Answer 13

solid at room temp
no double carbon bonds-straight
-more energy is needed to keep membrane fluid

Question 14

unsaturated lipids

Answer 14

liquid at room temp
with double hycarbon bonds-kinks [bent)
-less energy is needed to keepmemnrane fluid

Question 15

the effect of temp on the number of carbon atoms

Answer 15

the longer the carbon chain , the higher the temp needed to melt fatty acid to make it more fluid

(as the number of carbon atoms increases, the temp. increases)

Question 16

the effect on temo in the number of double bonds

Answer 16

as you add double bonds, the temperature decreases

Question 17

what does cholesterol do to a membrane

Answer 17

nonpolar
function: push apart the chains of saturated fatty acids( acting like a double bond (kink)
reducing the energy needed to make the membrane fluid

Question 18

membrane freeze-fracture analysis

Answer 18

-frozen cell surface is covered by a thick layer of carbon/ platinum for the electron to bounce off of
-observe that the membrane contains pits and mounds (only exterior contain mounds)
–> infe that proteins cause the pits and mounds

Question 19

polyAcrylamide Gel electrophoresis

Answer 19

proteins are separed by sized and charged

Question 20

SDS-polyAcrylamide Gel electrophoresis

Answer 20

separated based on size
native gel: allows proteins to be unchanged structurally
big to small

Question 21

TLC (Thin layer chromotography)

Answer 21

separated by polarity

plastic sheet coated with silica
nonpolar liquid
nonpolar things will be separated out

Question 22

laser/photobleaching

Answer 22

1. protein is dye with flourescent dye
2. photobleach spot with laser beam
3. recovery