Ch 6: Lipids

Question 1

Lipid

Answer 1

Carbon containing compounds largely non polar and hydrophobic

Lipid= fat!

Defined by their solubility

Question 2

Dehydration reactions

Answer 2

Join fatty acids to glycerol

Produce water

Question 3

Fats

Answer 3

Consists of glycerol linked to 3 fatty acids by ester linkages

Question 4

Amphipathic molecules

Answer 4

Both polar and non polar parts

• cholesterol
• phospholipid
• proteins

Question 5

Lipid micelles and lipid bilayers

Answer 5

Form spontaneously even though decrease of entropy.

-serine and phosphate groups are polar hydrophilic parts on outside, interact with water

Question 6

Permeability of bilayer

Answer 6

Gases (o2,co2,n2) = very permeable

Small uncharged polar molecules( water, indole, glycerol) = pretty permeable

Large, uncharged polar(sucrose, glucose) =semi/ not really permeable

Ions (cl-,k+,na+)= not permeable/ extremely slow

Question 7

Unsaturated fatty acids

Answer 7

Have double bonds

Cause kinks in tails= higher permeability

Question 8

Saturated lipids with long tails

Answer 8

Strong hydrophobic interactions= solid at room temp

Question 9

Unsaturated lipids tend to be

Answer 9

Liquid (oils) at room temp

Question 10

Amphoteric proteins can

Answer 10

Integrate into lipid bilayers

Question 11

Sandwhich model

Answer 11

Membrane proteins on outside of bilayer

-dropped in favor of fluid mosaic

Question 12

Fluid mosaic model

Answer 12

Membrane proteins integrated in bilayer

Question 13

Freeze fracture experiment

Answer 13

Evidence supporting fluid mosaic

• strike frozen cell with knife
• fracture splits lipid bilayer (exterior membrane, middle membrane)
• observe middle of membrane=pits and mounds. Exterior contains only mounds

Question 14

Lipids can act as Important signaling molecules

Answer 14

• Phospholipase C splits lipid at that interacts with ends reticulum
• opens calcium channel to release calcium