lecture 12

Question 1

What are key components of biological membranes that make them versatile?

Answer 1

boundary that defines cells and organelles
use and store energy
must be flexible and allow for self sealing
adaptable

Question 2

Whats a glycerophospholipid?

Answer 2

building block of biological membrane with polar head and fatty acid chain

Question 3

Whats a fatty acid?

Answer 3

carboxylic acid with long hydrocarbon chains
linear
can have 0-6 double bonds
always have even number of carbon

Question 4

Whats the omega carbon?

Answer 4

The final carbon in a fatty acid chain?

Question 4

Whats the omega carbon?

Answer 4

The final carbon in a fatty acid chain?

Question 5

What trends pertain to the mp of fatty acids?

Answer 5

As C-H bonds in the tail increase, so do the induced dipoles and the melting temperature
6-10C by each

Question 6

How do cis fatty acids affect melting point?

Answer 6

Decrease melting point by a lot bc difficult to pack tightly

Question 7

How do trans fatty acids affect melting point?

Answer 7

decrease mt by a bit but not as much as cis bc no 30C kink

Question 8

what’s a triacylglycerol?

Answer 8

glycerol headgroup with 3 fatty acid chains
hydrophobic and stored in lipid droplets in adipocytes

Question 9

What are the characteristics of lipids in the membrane?

Answer 9

soluble in non polar organic solvents
usually insoluble in H2O

Question 10

What are the three classes of membrane lipids?

Answer 10

glycerophospholipids/phosphoglycerides
sphingolipids
sterols

Question 11

What happens to mt at room temp depending on membrane composition?

Answer 11

more saturated fatty acids: more solid fat at RT, increase mp
more unsaturated: more liquid at room temp, decrease mp

Question 12

What is the structure of a glycerophospholipid?

Answer 12

polar head group, phosphate, glycerol, and fatty acid chains

Question 13

what is a phosphoserine?

Answer 13

a head group common in glycerophospholipids that has a phosphate

Question 14

What is a cardiolipin?

Answer 14

a diphosphoglyceride that compromises the inner mitochondrial membrane
it is an insulator and stabilizer of protein complexes

Question 15

Whats a sphingolipid?

Answer 15

serine+palmitate tale to to make ceramics chains

Question 16

What are the classes of sphingolipids?

Answer 16

sphingomyelins: found in myelin sheath and attach a phosphate containing head group
cerebroside: headgroup is a singular sugar like glucose or galactose
ganglioside: complex oligosaccharide head group with one silica acid

Question 17

What is a GM! ganglioside?

Answer 17

found in ganglion cells,
complex carb headgroup on outside of plasma membrane that binds specific protein and causes signal transduction for pituitary hormone and cholera
can lead to tay sachs

Question 18

What are the cholesterol membrane lipids?

Question 19

What does cholesterol do to a membrane?

Answer 19

decreases membrane fluidity

Question 20

What is a cholesterol

Answer 20

4 fused non polar rings, 3 6 member and. 5 member