Membrane

Question 1

Phospholipid Bilayer

Answer 1

Key term describing the structure of the membrane, 2 layers of phospholipids with polar heads on the outside and non-polar tails on the inside.

Question 2

Phospholipids are classified as?

Answer 2

Phosphoglycerides and sphingolipids

Question 3

Glycolipids can be classified as?

Answer 3

glycophosphoglycerides and glycosphingolipids

Question 4

what are the classifications of sterols

Answer 4

cholesterol in animals, phytosterol in plants and hopanoids in bacteria

Question 5

name the non protein things in the membrane

Answer 5

phospholipids, glycolipids and sterols

Question 6

describe the structure of a phospholipid

Answer 6

The head group is a phosphate group attached to an R group. The head is connected to the tail with a glycerol. The tail is a fatty acid, either saturated or unsaturated, which can bond to a sterol.

Question 7

Thermophiles

Answer 7

Organisms that live at high temperatures

Question 8

Psychrophiles

Answer 8

Organisms that live at room temperatures

Question 9

Mesophiles

Answer 9

organisms that live in low temperatures

Question 10

Lateral Mobility

Answer 10

The movement of lipids within one layer

Question 11

Flip flopping

Answer 11

the movement of lipids from one layer to the other

Question 12

Lipid Flippase

Answer 12

An enzyme responsible for flip flopping

Question 13

Integral proteins

Answer 13

proteins imbeded in the membrane. Interact strongly with lipids, require detergents to remove, include enzymes, antigens and receptors.

Question 14

Integral monotopic proteins

Answer 14

proteins that sit in one layer of the membrane

Question 15

single pass proteins

Answer 15

a protein that passes once through the membrane

Question 16

multipass protein

Answer 16

proteins that pass through the membrane multiple times

Question 17

multi-subunit proteins

Answer 17

multiple seperate polypeptides each passing through the membrane

Question 18

Peripheral membrane proteins

Answer 18

proteins loosely attached to the membrane, easy to remove

Question 19

lipid anchored

Answer 19

covalently bonded to lipids. Classified as fatty acid/prenyl/GPI anchored.

Question 20

functions of membrane proteins

Answer 20

cell junctions, enzymatic roles, structural roles, transport, sensing and recognising self vs. not self.

Question 21

The role of carbohydrates in the cell membrane

Answer 21

attach to proteins (glycoproteins) and lipids (glycolipids) to serve as ID tags for identification of self vs. not self

Question 22

Simple diffusion

Answer 22

Basically osmosis, requires no energy or special proteins

Question 23

Isotonic

Answer 23

Equal concentration with in and without the cell, nothing happens

Question 24

Hypertonic

Answer 24

higher concentration of solute outside the cell than in, leads to shrivelling

Question 25

Hypotonic

Answer 25

Higher concentration of solute inside the cell than out, leads to swelling and bursting

Question 26

Facilitated diffusion

Answer 26

diffusion across the membrane in line with the concentration gradient, proteins help overcome the permeability barrier. this requires no energy.

Question 27

Permeases

Answer 27

Proteins that allow for passage across the membrane, highly selective

Question 28

Active Transport

Answer 28

Transport acts against concentration gradient which requires energy. Used for nutrient uptake, waste removal and ion concentration maintenance

Question 29

Symport

Answer 29

2 different compounds going the same way

Question 30

Antiport

Answer 30

2 different compounds going in different directions

Question 31

uniport

Answer 31

1 compound traveling in one direction