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Flashcards in Test 2 Deck (241)
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1

Which protein in the red blood cell membrane appears to be responsible for the repelling forces that prevent RBCs from sticking to each other?

Glycophorin A

2

Muscular dystrophy is caused by:

mutations in the dystrophin gene

3

Membrane proteins are most likely analyzed to determine:

amino acid sequence

4

When looking for membrane spanning polypeptide sequences, cell biologists look for:

predominantly hydrophobic amino acids that form an α helix

5

Oligosaccharides are:

chains of fewer than 15 sugars.

6

What determines the difference between a person with O type blood and AB type blood?

The individual with AB type blood has genes for two enzymes that the person with O type blood does not.

7

Which of the following lowers the transition temperature of a membrane?

increasing unsaturation of fatty acids and shortening fatty acids.

8

Cells use desaturase enzymes to increase membrane fluidity in response to:

low temperature

9

The two leaflets of a cellular membrane:

have different mixes of lipids

10

Membrane fluidity is important for which of the following activities?

Allowing cell secretion to occur.

11

Using fluorescence recovery after photo bleaching allowed cell biologist to observe:

the diffusion of membrane proteins back into the bleached area.

12

Which statement about lipid movement within the phospholipid bilayer is true?

Lipids jump from one compartment to another to move laterally across the cell.

13

Which of the following involves the transport of a specific molecule across a membrane with the aid of a carrier protein, and additional energy input?

active transport

14

The diffusion of an electrolyte across a membrane is affected by:

both the concentration gradient and electrochemical gradient

15

Which statement about membrane permeability is true?

Non polar molecules penetrate faster than polar ones.

16

A cell shrinks when it is placed into a new solution. The new solution is probably:

hypertonic

17

The pump that uses ATP energy to concentrate protons into a lysosome is an example of a:

V-pump.

18

The Na+/K+ ATPase expels out of the cell and pumps into the cell.

Na+/K+.

19

People who are heterozygous for the CFTR protein may be more likely to survive cholera because:

heterozygous individuals have thicker mucus which may help prevent dehydration

20

Why can’t Na+ ions pass through the bacterial KcsA K+ channel?

Na+ ions are too small to replace the shell of hydration formed around the oxygen rings.

21

What part of the bacterial KcsA K+ channel undergoes conformational changes to allow the channel to open and close?

the M2 helices

22

The inner membrane of an axon goes from -80mV to +40mV during a wave of depolarization. What membrane protein is responsible for this depolarization?

voltage-gated Na+ channels

23

During saltatory conduction, depolarization occurs:

at the nodes of Ranvier

24

______ trigger fusion of synaptic vesicles with the synaptic membranes of the pre synaptic cell. These vesicles release ________ into the synapse.

Ca2+ ions, neurotransmitters

25

Which of the following inhibits acetylcholinesterase?

nerve gas

26

What is the affect of curare on a mammal?

It causes muscle paralysis.

27

Electrophoresis can be used to:

determine the number of peptides that make up a protein

28

Put the following in the correct order of appearance of organisms on the planet Earth from first to last: aerobes, anaerobes, cyanobacteria

anaerobes, cyanobacteria, aerobes

29

Which of the following is not evidence that mitochondria evolved from ancient aerobic bacteria?

Bacteria and mitochondria have about the same number of genes.

30

What would you expect to find in the intermembrane space of the mitochondria?

high proton concentration