Bio344-Exam#2 (Q's & A's) Flashcards

1
Q

What enzyme does cAMP activate?

A

protein kinase A

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2
Q

How can glucose transporters be inserted rapidly into the cell membrane after the cell detects insulin?

A

Glucose transporters are present in recycling endosomes which can fuse with the plasma membrane rapidly.

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3
Q

How do enzymes end up in the late endosome?

A

from the ER they go to the Golgi then the late endosome

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4
Q

How does a protein get directed to a specific cellular address?

A

The correct target has a receptor that binds the signal sequence of the protein.

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5
Q

Where is the signal recognition particle receptor located in the cell?

A

the ER membrane

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6
Q

What signal can activate a Jak-Stat pathway?

A

Interferon

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7
Q

What is autocrine signaling?

A

Occurs when a cell releases a signal and expresses a receptor for that signal at the same time.

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8
Q

Which of the following is true of the mitochondrial signal sequence?

A

it forms an alpha helix with one charged side while the other side is non-polar.

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9
Q

How do proteins get transported from the cytosol to the endoplasmic reticulum?

A

Transmembrane transport

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10
Q

What is a difference between an early endosome and a late endosome?

A

Endocytosed receptors are recycled from the early endosome and not the late endosome.

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11
Q

How can a mutation in dynamin lead to paralysis in fruit flies?

A

New synaptic vesicles can no longer be made because phospholipids are not recycled from the cell membrane

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12
Q

The Jak-STAT pathway is an example of…

A

enzyme linked receptor signaling pathway

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13
Q

Which is a difference between the cis and trans face of the Golgi apparatus?

A

Enzymatic reactions that occur in the cis face are different from those present in the trans face.

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14
Q

What does a kinase do?

A

it adds phosphate groups to proteins

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15
Q

Why are the Golgi in goblet cells in the small intestine not homogeneously distributed throughout the cell?

A

These cells release mucus which is only released from one end of the cell.

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16
Q

What are start and stop transfer sequences?

A

They are membrane spanning regions that determine how a protein is inserted into the ER membrane.

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17
Q

What happens to cargo after it has arrived at an early endosome?

A

it is sent to the late endosome

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18
Q

Where does the signaling molecule nitric oxide come from?

A

It is generated from arginine by an enzyme

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19
Q

Where are sugars first added to proteins?

A

Endoplasmic reticulum.

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20
Q

What is a difference between the early endosome and the late endosome?

A

The late endosome has proton transporters in its membrane while the early endosome does not

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21
Q

What is a function of a protein coat in vesicular transport?

A

It aids in bending the membrane and forming the transport vesicle.

22
Q

Why does invagination happen in multivesicular bodies that form between early and late endosomes?

A

So that membrane proteins can be degraded completely.

23
Q

What does a G-protein linked receptor do when it binds a signal?

A

It replaces the GDP of a G protein with GTP.

24
Q

What molecule provides the energy to actively transport proteins from the cytosol into the nucleus?

A

Ran-GTP

25
Q

Which receptor binds antibodies?

A

the Fc receptor

26
Q

What enzyme makes cAMP?

A

adenylyl cyclase

27
Q

Why is a phospholipid exchange protein needed to transfer phospholipids to the mitochondria?

A

Because there is no vesicular traffic to mitochondria to deliver phospholipids.

28
Q

What is the content of secretory vesicles that wait near the plasma membranes of beta cells in the pancreas?

A

insulin

29
Q

What kind of protein coat is present on vesicles transporting cargo from the cell membrane to an early endosome?

A

Clathrin

30
Q

What is a low density lipoprotein particle?

A

It is a protein that delivers cholesteryl esters to cells

31
Q

What is likely to happen to a receptor, such as the LDL receptor, once it has delivered its cargo?

A

It is recycled back to the cell membrane.

32
Q

What kind of N-linked oligosaccharides are generated in the Golgi apparatus?

A

complex oligosaccharides

33
Q

What is a function of the Golgi Apparatus?

A

This is where the original oligosaccharide precursor is modified

34
Q

How do cells take up the correct substrates in endocytosis?

A

A receptor, specific for the substrate, will concentrate it into endocytic vesicles.

35
Q

What type of filament is used to move multivesicular tubular clusters?

A

microtubules

36
Q

What is a domain present on a nuclear receptor that binds steroid hormones?

A

A DNA binding domain

37
Q

Where is there a reservoir of calcium inside the cell?

A

Endoplasmic Reticulum

38
Q

Which below is an important class of cell surface receptors?

A

G-protein linked receptors

39
Q

What is a difference between a G-protein linked receptor and an enzyme linked receptor?

A

The enzyme linked receptor phosphorylates itself and can phosphorylate other proteins; the G protein linked receptor cannot.

40
Q

What would be the consequence of a mutant low-density lipoprotein particle receptor that does not bind to adaptin?

A

More LDL particles in the blood stream.

41
Q

Where are phospholipids made in the cell?

A

In the cytosolic layer of the smooth ER membrane.

42
Q

How are proteins often activated in signaling pathways?

A

they are phosphorylated.

43
Q

How do cargo vesicles fuse with the membrane of the target compartment?

A

SNARE proteins bring the membranes of the vesicle and target compartment close together so they can fuse.

44
Q

What does a mast cell do?

A

It releases histamines

45
Q

What kind of protein coat is present on vesicles transporting proteins from the ER to the Golgi?

A

COP II

46
Q

What signal tag is required to send a protein to the lysosome?

A

Mannose 6 phosphate

47
Q

Which organelle is responsible for carbohydrate synthesis?

A

Golgi apparatus

48
Q

Where are G-proteins located inside the cell?

A

on the cytoplasmic face of the plasma membrane

49
Q

What is the form of intercellular signaling that involves hormones called?

A

endocrine signaling

50
Q

Insulin binds to:

A

an enzyme linked receptor