Lecture 4 Most Recent Notes

Question 1

Name three factors that increase membrane fluidity

Answer 1

1. Shorter fatty acid length
2. Increased presence of unsaturated fatty acids
3. Decreased cholesterol content of the membrane

Question 2

What are the three primary types of lipids found in membranes?

Answer 2

1. Phospholipids
2. Glycolipids
3. Cholesterol

Question 3

What are the two sub-types of phospholipids? (based on what they are made from)

Answer 3

1. Those made with a glycerol backbone (used as a sweetner)

2. Those made from sphingosine (From brain extracts, named after the sphynx)

Question 4

What is the most abundant type of lipid found in the membranes, and what is its function?

Answer 4

Phospholipids are most abundant, and provide a barrier to diffusion

Question 5

Phosphatidate is an intermediate in a variety of what kind of pathways?

Answer 5

Fatty acid pathways

Question 6

Palmitic fatty acids: How many carbons? Is it saturated or unsaturated?

Answer 6

16 carbons, saturated

Question 7

Stearic fatty acid: How many carbons? Is it saturated or unsaturated?

Answer 7

18 carbons, saturated

Question 8

How many carbons are in oleic fatty acid? How many double bonds are there?

Answer 8

18 carbons, 1 double bond

Question 9

How many carbons are in linoleic fatty acid? How many double bonds?

Answer 9

18 carbons, 2 double bonds

Question 10

How many carbons are in linolenic fatty acid? How many double bonds are present?

Answer 10

18 carbons, 3 double bonds

Question 11

How many carbons in arachidonic fatty acid? How many double bonds are present?

Answer 11

20 carbons, 4 double bonds

Question 12

What three structures is arachidonic fatty acid a precursor intermediate?

Answer 12

1. Prostaglandins (prevent unncessary clot formation)
2. Thromboxane (vasoconstrictor)
3. Leukotryeins (stimulates proinflammatory activities)

Question 13

What is the function of sugars in cells?

Answer 13

“Recognition”-to recognize molecules that may be signals or as parts of other cells or proteins

Question 14

What are three important glycolipids?

Answer 14

1. Cerebrosides (found in animal muscle and nerve cell membranes)
2. Sulfatides (cell aggregation and adhesion)
3. Gangliosides (Cell to cell communication)

Question 15

What two diseases are in relation to the body not being able to process glycolipids?

Answer 15

Gaucher’s disease

Tay-Sachs Disease

Question 16

What do glycolipids do as part of glycocalyces? (3 functions)

Answer 16

1. Recognize other cells
2. Form links between cell and the ECM and other cells
3. Absorbing molecules at the cell’s surface