CELL PHYSIOLOGY REVIEW QUESTIONS, BIOL 580 Make sure that all your answers have experiments or examples to back them up- some kind of proof that you know what you are talking about.

CYTOSKELETON

NON-MUSCLE CELLS ASSEMBLIES OF ACTIN AND MYOSIN

What proteins stabilize actin filaments or actin monomers?

What is the difference between myosin I and II?

What kinds of actin structures are present as a result of activation of Rho, Rac, or CDC42? What kinds of factors can influence where actin is polymerizing and where it is being fragmented?

What are MAPS? How can MAPS control assembly or disassembly of MT? What is the difference between + and - ends of MT? What kinds of things influence + end, - end? What is the effect of Ca++ on MT, and does that involve calmodulin. What is the difference between control proteins for cilia and flagella and for vesicular transport? Are there cases where MT of tubulin act as skeletal elements or stabilizers as do stress fibers of actin?

What do we mean by motor protein? Which motors move toward the cell center and which to cell edge. Which motors work on MT and which on MF?

Does endocytosis or secretion depend on cytoskeletal events? How is calcium involved in secretion? How is secretion involved with growth in plant and animal cells?

What is the significance of having families of genes for actin, myosin, tubulin present in cells? Could there be domains for control or binding of control proteins specific for different functions?

Is MT motion important in amoeboid movement, and how do you know?

What kinds of factors influence cell motility or cytoplasmic streaming?

How is assembly and disassembly of actin or tubulin important to the cell? What does this have to do with amoeboid movement? How do we get orderly arrays of cytoskeletoal elements as compared to random arrays? Contrast movement utilizing the two systems. How can ATP energy be converted into cell motility? What does sol‑gel interconversion have to do with cell motility?

. How is the cytoskeleton related to the cell membrane?

7. Explain one possible way for a protein to become a part of the cell membrane.

8. Describe one way that membranes are asymmetric and how this can be demonstrated.

13. How do you know that lipid content is important in membrane function?

3. What properties of actin may be involved in protoplasmic streaming as seen in amoeboid movement?

4. What do dynein and myosin have in common?

_____6. demonstrates polarity of actin filaments

_____7. a second messenger formed from PIP2

CELL SIGNAL

How is chemotaxis related to cell movement?

_____2. altered by the state of G‑protein adjacent

4. What is the importance of signal transduction?

9. Discuss adaptation in bacterial chemotaxis.

MULTIPLE CHOICE Enter the letter of the one correct answer on your scantron. 2 points each.

50. In amoeboid movement,

a. there may be very little actin as compared to the amount of myosin

b. there may be very little myosin as compared to the amount of actin

c. the cytoplasm contracts at the rear of the cell and squeezes the rest of the cytoplasm forward

d. sliding of microtubules is involved

e. colchicine prevents it.

51. The peripheral doubletsw of the axoneme:

a. all bend during cilia beating

b. extend further into the tip on the outer side of the bend

c. have spokes which slide up and down other microtubules

d. have dynein arms which contract during beating

e. have attached spokes which bind to the central doublet sheath elements.

56. The difference between phosphatidylcholine and sphingomyelin is that :

a. only PC is a glycerolipid

b. only PC has two acyl chains

c. only PC is a phospholipid

d. only SPH is found in nerve cell membrane

e. none of the above

58. Which of these in the extracellular matrix does the cell membrane bind to?

a. chondroitin sulfate

b. heparin sulfate

c. fibronectin

d. hyaluronic acid

e. none of the above

48. Which of the following does not bind to actin filaments to make a meshwork: a. fascin b. fimbrin c. alpha actinin d. filamin e. profilin

49. When a cell rounds up, it usually means: a. cytoskeleton

is in a complex meshwork b. it has many stress fibers c. it has extensive filopodia d. it has lost its stress fibers and plaques e. none of the above

50. When a cell is elongated, chances are it has: a. many long microtubules helping to keep it long b. adhesive sites to the substratum c. a complex microtrabecular meshwork d. polarity of channels in the membrane e. all of the above

28. Amoeboid movement is associated with: a. microtubules b. sol‑gel transformations c. polymerization‑depolymerization of actin d. all the above e. only b and c above

2. We have discussed several regulatory proteins for the cytoskeleton and the membrane enzymes. What kinds of things regulate the regulatory proteins (allow them to have an effect or turn them off)? Give examples. Do not just describe what regulatory proteins do.

1. Discuss two controlling proteins that can alter the tertiary or quaternary structure of other proteins, using specific examples.

1. Briefly explain how the use of three of the following treatments on a group of cells or bits of information about them could help to determine whether the method of transduction of a stimulus is through Ca++, IP3, cAMP, diglyceride, arachodonate or a mixture of these.

a. The effect is mimiced by A23187, an ionophore.

b. The effect is inhibited by EGTA in the external medium

c. GTP is required

d. treatment with phospholipase mimics the effect

e. ATP is required

f. PI is broken down in the reaction

g. the effect is not inhibited by external EGTA

h. phosphodiesterase inhibitors such as caffeine amplify the reaction

i. pertussis toxin prevents control of the response

j. lithium inhibits the reaction

1. List two ways to control free calcium concentrations in cells, and give an example of how each is used to control cell activities.

What is the polar coordinate model?

What is the shortest intercalation rule? Explain why some experiments produce duplications and some produce intercalations.

3. Describe some aspects of cell polarity at the molecular level, give examples. (This is not membrane polarity.)

How can sorting of components of different sides of epithelium occur? How are docking sites determined?

Polarity in eggs:

Describe the animal‑vegetal axis and how and where it is set?

The axes and planes of symmetry of the frog embryo depend upon interactions between which factors?

What kinds of factors are important in localization of bicoid and oscar or nanos in fly eggs?

What results after treatment with lithium chloride.

Describe events leading to setting axes in the frog or fly embryo (dorsal- ventral, anterior-posterior).

Cite evidence for stored mRNA in eggs.

FERTILIZATION 1. What changes are formed in egg cortex following fertilization?

What determines the location of the grey crescent in amphibians?

Present evidence that cell characteristics of grey crescent cells are different from other embryo cells. How do you think they became different?

What is the difference between cell-cell adhesion and cell -ECM adhesion?

How can cells have different structure and function for different sides?

What is the significance of cytoplasmic movement or shifts after fertilization? Give some examples and how you can prove something significant happened.

SIGNAL RECEPTION, RECEPTOR DISTRIBUTION

Discuss the types of second messengers produced after signal transduction.

What do these second messengers do to cause changes in cell behavior?

Describe Cell control mechanisms including: a) changes in pH b) changes in amount of free calcium c) phosphorylation of proteins to alter the activity or structure d) receptor internalization c) secretion to alter the surface

How can the cell interactions be used as a model to prove how cellular interactions may involve growth factors, gene activation, receptor synthesis, surface reactions including cell adhesion.

What is the difference between having stored information for certain functions and being able to respond to inductions of different sorts?

What is a pleckstrin homology domain? A Sarc (SH2 or SH3) homology domain?

How does phosphorylation control them, and how is it accomplished?

What kinds of things depend upon binding to these domains to become active?

How can proteins change from being in cytosol to being attached to membrane?

RECEPTORS

How can phosphorylation and methylation be used as control mechanisms?

How can different alpha subunits influence G proteins function?

How can beta gamma subunits be controlled and what do they control?

List two ways to control free calcium concentrations in cells, and give an example of how each is used to control cell activities

What is a growth factor and how is the RAS-gene product related to it?

How is G-protein and adenyl cyclase involved?

How does a cell know when to divide- what control mechanisms are there and what kinds of external factors can alter the control mechanisms? What kinds of signal transduction are involved and what happens at the molecular level to initiate, to assemble the machinery, to provide energy for the work which is done, to stop when finished.

CELL ADHESION

1. How can one cell influence another to move or divide or stop dividing?

2. How can the extracellular environment influence a cell to move or divide or stop moving or dividing?

3. What kind of cell membrane components or receptors are involved? Is there an effect on the cytoskeleton?

4. How is cell adhesion related to cell division, cell motility, extracellular matrix? What are some of the molecules involved?

What kinds of enzymes can have the type of domain to attach to growth factor receptors? How can that cause cells to change their behavior? What is GRB, how is it related to ras and why is it important?