01a: Membranes

Question 1

The direct cause of lysosomal storage diseases:

Answer 1

Accumulation of sphingolipids in the lysosome

Question 2

Peroxisomes play a role in (degradation/biosynthesis).

Answer 2

Both

Question 3

Cellular lipids are degraded via (X) reaction, carried out by which organelle(s)?

Answer 3

X = beta-oxidation

Peroxisomes

Question 4

Describe the break down of cellular lipids by beta-oxidation.

Answer 4

1. Hydrocarbon chain degraded 2 C units at a time

2. Acetyl molecules transported into cytosol for biosynthesis

Question 5

T/F: Peroxisomes are required for synthesis of all glycerolipids.

Answer 5

False - only some glycerolipids

Question 6

(X) is major site of ATP synthesis.

Answer 6

X = mitochondrion

Question 7

A spherocyte, aka (X), is indicative of:

Answer 7

X = RBC that’s spherical in shape

hemolytic anemia

Question 8

T/F: Accumulation of protein aggregates can change a cell’s shape.

Answer 8

True

Question 9

Which organ(s) can destroy spherocytes?

Answer 9

Spleen only

Question 10

What are the major lipids found in the PM?

Answer 10

1. Glycerophospholipids
2. Sphingolipids
3. Cholesterol
4. Other lipids (i.e. glycolipids)

Question 11

Phosphatidylcholine is an example of a (X).

Answer 11

X = glycerophospholipid

Question 12

Give some examples of molecules present in glycerophospholipid head?

Answer 12

Choline, serine, ethanolamine, inositol

Question 13

Give some examples of molecules that connect head and tail in a glycerophospholipid?

Answer 13

Phosphate, glycerol

Question 14

Glycerophospholipid tails are composed of:

Answer 14

2 FA chains (1 saturated and 1 unsat)

Question 15

What’s the key difference between sphingolipids and glycerophospholipids?

Answer 15

Sphingolipids derived from sphingosine, not glycerol

Question 16

Lattice structure composed of (X) gives the RBC its shape. Where is this lattice, wrt the cell?

Answer 16

X = alpha and beta spectrin proteins

On cytoplasmic surface of membrane

Question 17

Alpha and beta spectrin attached (directly/indirectly) to plasma membrane by:

Answer 17

Indirectly; spectrins attached to Ankyrin, which attaches to Band 3 (an integral membrane protein)

Question 18

Atypical pneumonia is caused by (X), a bacterium that (secretes/extracts) (Y).

Answer 18

X = Mycoplasma pneumoniae
Extracts;
Y = Cholesterol from cell membrane

Question 19

T/F: Lipids in plasma membrane can flip-flop in trans between each layer of bilayer.

Answer 19

True

Question 20

List the key things that affect membrane fluidity.

Answer 20

1. Temperature
2. FA chain length
3. Cholesterol content
4. Unsaturation of tails

Question 21

Increase temperature, (increase/decrease) membrane fluidity.

Answer 21

Increase

Question 22

Increase cholesterol content, (increase/decrease) membrane fluidity.

Answer 22

Decrease

Question 23

Increase FA chain length, (increase/decrease) membrane fluidity.

Answer 23

Decrease

Question 24

Increase unsaturation of FA chain, (increase/decrease) membrane fluidity.

Answer 24

Increase

Question 25

Mycoplasma pneumoniae affect which specific structure(s) in atypical pneumonia?

Answer 25

Less cholesterol, more fluidity in bronchial cilia membrane; become limp and incapable of beating (mucous accumulation and decrease in rich medium for mycoplasma propagation)

Question 26

Why are liposome drugs beneficial for delivery chemotherapeutic agents?

Answer 26

Cancer tissue is warmer than regular tissue (inflammatory response), so drug release easier

Question 27

Release of drugs from liposomes requires which key protein type?

Answer 27

X = integrins