2.2

Question 1

why do people with CF have stickier mucus?

Answer 1

contains less water

Question 2

why do people with CF’s mucus contain less water?

Answer 2

abnormal salt and water transport across the cell surface membranes caused by a faulty transport protein channel in the membrane

Question 3

what is the general structure of an amino acid?

Answer 3

a carbon with an amine group to the left (N-H-N), a carboxylic acid group to the right and a residual group at the bottom

Question 4

how do amino acids join together?

Answer 4

in a condensation reaction forming a peptide bond

Question 5

what is the primary structure of a protein?

Answer 5

the sequence of amino acids joined together by peptide bonds

Question 6

what is the secondary structure?

Answer 6

When the polypeptide chain coils into a shape

Question 7

what are the two types of secondary structure?

Answer 7

a - helix
b - pleated sheets

Question 8

what is the tertiary structure?

Answer 8

when the secondary structures folds into a three dimensional shape due to the interactions between amino acids in the chain

Question 9

what is a quaternary structure?

Answer 9

proteins with more than one polypeptide chain

Question 10

what bond occurs between two inward facing amino acids?

Answer 10

a covalent disulphide bond between R groups

Question 11

what kind of R groups face the inside of the protein?

Answer 11

hydrophobic

Question 12

what do ionised R groups form?

Answer 12

ionic bonds

Question 13

what are the pros and cons of disulphide and ionic bonds compared to hydrogen bonds?

Answer 13

they are much stronger but also more sensitive to pH change

Question 14

what are conjugated proteins?

Answer 14

they have another chemical group associated with their polypeptide chain

Question 15

what are globular proteins?

Answer 15

they have a polypeptide chain that is folded into a compact spherical shape and are soluble

Question 16

what are fibrous proteins?

Answer 16

they remain as long chains that can be cross linked and are insoluble

Question 17

what is a cell membrane?

Answer 17

a phospholipid bilayer

Question 18

what part of the phospholipid is hydrophilic?

Answer 18

the phosphate head

Question 19

what part of the phospholipid is hydrophobic?

Answer 19

the fatty acid tail

Question 20

what two structures can phospholipids form?

Answer 20

micelles and bilayers

Question 21

where are the hydrophobic areas of the membrane proteins found?

Answer 21

within the membrane bilayer

Question 22

describe the fluid mosaic model?

Answer 22

some of the proteins are fixed within the membrane, but others are not and can move around in the fluid phospholipid bilayer

Question 23

what makes the membrane more fluid?

Answer 23

having a greater ratio of phospholipids that contain unsaturated fatty acids to those with saturated

Question 24

name the six ways substances can pass through a cell membrane?

Answer 24

diffusion, facilitated diffusion, osmosis, active transport, exocytosis and endocytosis

Question 25

what is the definition of diffusion?

Answer 25

the net movement of molecules or ions from a region where they are at a higher concentration to a region of their lower concentration

Question 26

what is facilitated diffusion?

Answer 26

when larger hydrophilic molecules or ions cross the membrane with aid of channel or carrier proteins

Question 27

how do carrier proteins work?

Answer 27

the ion or molecule bonds into a specific site on the protein, the protein changes shape and it can move across

Question 28

what is the definition for osmosis?

Answer 28

the net movement of water molecules from a solution with a lower concentration of solute to a solution with a higher concentration of solute through a partially permeable membrane

Question 29

when will osmosis stop?

Answer 29

when the solutions are isotonic

Question 30

what is active transport?

Answer 30

substance moving from a low to high concentration which requires energy

Question 31

where is the energy for active transport supplied from?

Answer 31

ATP