Topic 2- Genes and Health

Question 1

what are the properties of gas exchange surfaces in living organsisms

Answer 1

• large surface area: volume ratio
• thin
• steep concentration gradient

Question 2

fick’s law of diffusion

Answer 2

(area of diffusionxdifference in conc)/thickness of exchange surface

Question 3

how is the structure of the mammalian lung adapted for efficient gas exchange

Answer 3

• alveoli
• large sfa:vol ratio
• moist (gases can diffuse)
• steep concentration gradient (capillaries)
• one cell thick

Question 4

hydrophilic definition

Answer 4

water loving

Question 5

hydrophobic definition

Answer 5

water hating

Question 6

polar definition

Answer 6

electrons not equally distributed

Question 7

partially permeable definition

Answer 7

only small molecules can pass through

Question 8

what are phospholipids made up of

Answer 8

phosphate group head (hydrophilic+polar)
phosphoester bond
glycerol
ester bond
fatty acid (hydrophobic+non-polar)

Question 9

explain how a phospholipid bilyer is formed

Answer 9

1. the hydrophobic non-polar tails arrange themselves so that they are never in contact with an aqueous environment
2. the hydrophilic polar heads will always face the aqueous environment
3. They form a double layer

Question 10

what are integral proteins

Answer 10

go all the way through the 2 layers: channel/carrier proteins

Question 11

what are peripheral proteins (glycoproteins + glycolipids)

Answer 11

found on only one layer, often act as enzymes or receptors

Question 12

what are glycoproteins

Answer 12

carbohydrate molecule on the peripheral protein
- involved in cell-to-cell recognition and receptors

Question 13

what are glycolipids

Answer 13

carbohydrate molecule attached to the head of a phospholipid

Question 14

what is cholesterol

Answer 14

Sits between the tails of the phospholipids and maintains fluidity of the membrane by affecting the movement of the phospholipids