Cell Biology Lectures 19-20 (Part 2)

1.

1 point

The synaptic signaling has an high speed, a __________ concentration, and low affinity.

2.

1 point

The α subunit of the inactive G protein has:

GTP bound

GDP bound

ATP bound

ADP bound

3.

1 point

Which of the following is false abut combinatorial Signaling

Cells would survive if they contain at least one signal

Cells would survive and growth if they contain a few signals

Cells would survive even if they don't contain any signal

Cells would survive and differentiate if they contain a few signals

4.

1 point

In the fly, what is one process that Notch signaling regulates?

Nerve Development

Combinatorial Signal

Combinatorial Development

All of the above

5.

1 point

The most common molecular switch uses

Surface receptors

Small intracellular messenger molecules

Protein Phosphorylation

Enzyme-coupled receptors

6.

1 point

Which of the following is false according to cortisol activates a nuclear receptor protein?

Cortisol is produced by the adrenal glands in response to stress

Cortisol diffuses across plasma membrane and binds to a nuclear receptor in the cytosol

Receptor is then translocate into the nucleus where it activates specific target genes

None of the above

7.

1 point

Contact-dependent

released signal by cells into extracellular fluid. Act locally.

secrete hormones that travel in the blood throughout the body.

can extend for a long distance to deliver message to target cells.

cell surface-bound signal molecule binds to receptor on adjacent cell

8.

1 point

Which of the following is true about contact-dependent signaling controls nerve development in the fly

The fly nervous system originates in the embryo from a sheet of epithelial cells.

Cells destined to be nerve cells express higher levels of Delta than surrounding cells.

Delta binds to Notch receptors on target cells and inhibits them from becoming neurons.

All of the above

9.

1 point

Gap junctions allow neighboring cells to share some signaling information by all of the following except:

Channels that directly connect cells, such as adjacent epithelial cells or neurons

Does not allows direct cell-cell communication

Does not allow exchange of macromolecules such as proteins

Allow exchange of small water soluble molecules such as Ca2+, cAMP

10.

1 point

Paracrine

can extend for a long distance to deliver message to target cells.

secrete hormones that travel in the blood throughout the body.

cell surface-bound signal molecule binds to receptor on adjacent cell

released signal by cells into extracellular fluid. Act locally.

11.

1 point

Which of the following is false about the principles of signal transduction?

Signal conversion process called “signal transduction”

Most cells can only send signals but not receive

Receptor proteins in target cells respond to signaling molecules.

Extracellular signals are converted into intracellular signals.

None of the above

12.

1 point

GTP-binding proteins as a molecular switch because

Switch between active and inactive state depends on whether they have GTP or GDP bound

Once activated, an intrinsic GTPase activity causes them to shut themselves off

One class of these proteins are the G proteins that relay messages from G-protein-coupled receptors (GPCRs)

All of the above

13.

1 point

Cell surface receptors can relay messages inside the cell

True

False

14.

1 point

GPCRs are the largest family of cell-surface receptors.

True

False

15.

1 point

A Cortisol binds to membrane-bound receptors.

True

False

16.

1 point

How do paracrine signals remain local

The Signaling molecule is short-lived

Can be degraded rapidly by extracellular enzymes

Can be taken up rapidly by neighboring target cells

All of the above

17.

1 point

Which of the following is true about G-protein coupled receptors?

Rapid synaptic signaling between nerve cells

Neurotransmitters transiently open or close ion channels by binding to them

Indirectly regulates activity of separate plasma and membrane-bound target protein

None of the above

18.

1 point

Most signaling molecules are small and hydrophobic

True

False

19.

1 point

The sense of sight, smell and taste are all controlled by GPCRs

True

False

20.

1 point

Neuronal

secrete hormones that travel in the blood throughout the body.

cell surface-bound signal molecule binds to receptor on adjacent cell

can extend for a long distance to deliver message to target cells.

released signal by cells into extracellular fluid. Act locally.

21.

1 point

Which of the following is not a type of signaling molecules?

Proteins

Small peptides

Steroids

Fatty acid derivatives

Dissolved gases

None of the above

22.

1 point

GTP-Binding Protein as a molecular switch

Depends on balance of kinases and phosphatases

The second largest class of molecular switch proteins use this mechanism

The largest class of molecular switch proteins use this mechanism

All of the above

23.

1 point

Which one is not a type releasing of signal molecules

Most released by the signaling cell via endocytosis

Most released by the signaling cell via exocytosis

Some released by diffusion through plasma membrane

Others are displayed on cell surface

24.

1 point

Which of the following is not true about Long-range signaling: Synaptic Signaling

Action potentials created by voltage-gated sodium or calcium channels

Once released, neurotransmitters travel very far

Neurotransmitters are concentrated and receptors have low affinity for signaling molecule

None of the above

25.

1 point

Cells with no signals from other cells will die.

True

False

26.

1 point

Nitric oxide can diffuse across cell membranes.

True

False

27.

1 point

Acetylcholine generates the same response in all cell types.

True

False

28.

1 point

How many times do GPCRs pass through the cell membrane?

5 Pass the Transmembrane

6 Pass the Transmembrane

7 Pass the Transmembrane

8 Pass the Transmembrane

29.

1 point

Which of the following is not true about signaling in multicellular organisms?

During evolution to multicellular animals, signaling has become more elaborate and cells must work together for the good of the organism

Signaling mechanisms conserved through evolution in multicellular organisms

Flies, worms and have conserved signaling pathways with mammals

Genes involved in signaling can be grouped into families

None of the above

30.

1 point

Acetylcholine signaling stimulates the creation of nitric oxide in endothelial cells.

True

False

31.

1 point

What can amplify messages?

Small intracellular messenger molecules

Enzyme-coupled receptors

Surface receptors

Protein Phosphorylation

32.

1 point

Which of the following is true about Long-range signaling: Endocrine Signaling?

Relies on diffusion and blood flow and works over long distances

Slow process and hormones act at low concentrations

Receptors bind hormones with high affinity

All of the above

33.

1 point

The endocrine signaling has an slow speed, a __________ concentration, and high affinity.

34.

1 point

Nitric oxide causes smooth muscles to relax.

True

False

35.

1 point

Which one is not true about protein phosphorylation as a molecular switch

Depends on balance of kinases and phosphatases

The second largest class of molecular switch proteins use this mechanism

The largest class of molecular switch proteins use this mechanism

All of the above

36.

1 point

A fast signaling response is the result of new protein synthesis.

True

False

37.

1 point

Both activated parts of the G protein (α and βγ) can bind to and activate target proteins depending on the particular target.

True

False

38.

1 point

Which of the following is not true abut budding yeast cells respond to a mating factor

Haploid yeast that are ready to mate secrete mating factor

Yeast of opposite mating type stop proliferating and prepare to mate.

Protrusion extended towards the source of the mating factor

Budding yeast are normally rectangular

None of the above

39.

1 point

Which of the following is not true about Ion-Channel coupled receptors?

Rapid synaptic signaling between nerve cells

Neurotransmitters transiently open or close ion channels by binding to them

Indirectly regulates activity of separate plasma and membrane-bound target protein

None of the above

40.

1 point

Which of the following is false about dissolved gases cross the plasma membrane and directly activate enzymes

Stimulates NO to stop production of arginine

Causes smooth muscle cell relaxation

Acetylcholine released by nerve terminal in blood vessel wall and binds receptor on endothelial cell

NO diffuses into smooth muscle cells and binds NO receptor

41.

1 point

Estradiol binds to intracellular receptors.

True

False

42.

1 point

G proteins are

Monomers

Dimers

Trimers

None of the Above

43.

1 point

Identify which of the following is not correct according to the length of the signaling molecules

Contact-dependent are short

Paracrine cells are short

Neuronal cells are long

Endocrine are short

44.

1 point

Unicellular organisms can communicate with each other

True

False

45.

1 point

A treatment for angina is:

Injection of enzyme in the blood

Insulin

Nitroglecerin

None of the Above

46.

1 point

Which of the following is true about Enzyme-coupled receptors?

Rapid synaptic signaling between nerve cells

Function directly as enzymes or associate with enzymes

Indirectly regulates activity of separate plasma and membrane-bound target protein

None of the above

47.

1 point

Some signals can integrate together.

True

False

48.

1 point

Endocrine

released signal by cells into extracellular fluid. Act locally.

can extend for a long distance to deliver message to target cells.

secrete hormones that travel in the blood throughout the body.

cell surface-bound signal molecule binds to receptor on adjacent cell

49.

1 point

Yeast can respond to the release of mating factor.

True

False

50.

1 point

Gap junctions allow neighboring cells to share some signaling information by:

Channels that directly connect cells, such as adjacent epithelial cells or neurons

Allow exchange of small water soluble molecules such as Ca2+, cAMP

Does not allow exchange of macromolecules such as proteins, but allows direct cell-cell communication

All of the above