CELL PHYSIOLOGY review

REVIEW QUESTIONS, BIOL 580 CYTOSKELETON What kinds of factors influence cell motility or cytoplasmic streaming? Sort out which affect cilia, which affect amoeboid movement, which muscle contraction. What is the difference in their targets? Separate these agents into groups with related functions: .nf actinin desmin keratin profilin gelsolin fimbrin fascin tropomyosin kinesin dynein actin myosin tubulin nexin MAPS meromyosin calmodulin protein kinase EGTA and EDTA troponin vinblastine colchicine cytochalasin calcium magnesium ATP GTP creatine kinase

Compare and contrast control of striated vs cardiac vs smooth muscle contraction and relaxation. 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 do the different solubility properties of cytoskeletal proteins allow for their purification? What is the difference between doublet microtubules in the axoneme and cytoplasmic microtubules? What is the evidence either for or against microtubules or microfilament activity in cytoplasmic streaming and amoeboid movement? What is the basis for the sliding filament model for muscle contraction and the sliding tubule model for ciliary movement? Are there different functions for cytoskeletal elements, so that they may change between dynamic and static? What are stress fibers and neurofilaments? How is chemotaxis related to cell movement? Why do you think cells can't live for long without cytoskeleton? How can molecules change due to binding of ions or ATP? How can you get proteins to come off of ion exgange resins, once they bind? Is this related to the previous question? How can phosphorylation and methylation be such important control mechanisms? ated to the previous question? How can phosphorylation and methylation be such important control mechanisms?

Receptors 6. CONTRAST STEROID AND PEPTIDE HORMONE RECEPTOR ACTIVATION AND MODULATION 7. HOW CAN cAMP PRODUCED BY THE SAME HORMONE-RECEPTOR INTERACTIONS ELICIT DIFFERENT RESPONSES IN DIFFERENT CELLS? 8. HOW CAN CELLS INFLUENCE MOTILITY OR DIVISION RATE OF OTHER CELLS? 9. WHAT KINDS OF CONTROL MECHANISMS COULD BE DISRUPTED IN CANCER CELLS, SO THEY DIVIDE MORE RAPIDLY AND ARE NOT INFLUENCED BY OTHER CELLS? 3. HOW CAN SECRETION AFFECT A) THE CELL DOING THE SECRETION, B) OTHER CELLS. 8. WHY IS CALCIUM CALLED A SECOND MESSENGER?

Nervous System 11. WHAT EVENTS OCCUR AT THE SYNAPSE OF THE POSTSYNAPTIC CELL AT TRANSMISSION? 12. WHAT EVENTS OCCUR AT THE SYNAPSE OF THE PRESYNAPTIC CELL AT TRANSMISSION? 5. IF THE RESTING POTENTIAL IS +20 mV WHAT WOULD BE YOUR GUESS ABOUT THE PERMEABILITIES OF NA AND K THROUGH THE CELL MEMBRANE? 1. WHAT ARE THE COMPONENTS OF A VOLTAGE CLAMP EXPERIMENT, AND HOW HAS THIS TYPE OF EXPERIMENT BEEN USEFUL IN ELUCIDATING CELL MEMBRANE FUNCTION? 2. WHAT IS ONE HYPOTHESIS TO EXPLAIN THE DIFFERENCE OF NA AND K CONCENTRATION INSIDE THE CELL AS COMPARED TO OUTSIDE THE CELL? 3. WHAT KINDS OF FACTORS ARE IMPORTANT IN REGULATING THE ELECTROCHEMICAL POTENTIAL OF THE CELL? 4. WHAT ARE THE DIFFERENCES BETWEEN A RESTING CELL MEMBRANE AND A STIMULATED CELL MEMBRANE AND A RECOVERING CELL MEMBRANE?

Vision 2. WHAT IS THE PHYSIOLOGICAL BASIS FOR ONE IMPORTANT DIFFERENCE BETWEEN THE RESTING STATE IN RODS AND CONES AS COMPARED TO NERVE CELLS? 3. WHAT IS A COMMON THEME FOR PROTEINS INVOLVED IN CHANGES OF STATE SUCH AS IN VISION OR CONTRACTION OR CILIARY MOTION?

Cell Membrane 6. 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. 9. HOW CAN COATED PITS HELP LARGE MOLECULES TO PASS INTO THE CELL? 10. PRESENT SOME EVIDENCE THAT THE CELL MEMBRANE IS NOT A HOMOGENEOUS MATERIAL ON THE CELL SURFACE. 13. HOW DO YOU KNOW THAT LIPID CONTENT IS IMPORTANT IN MEMBRANE FUNCTION? 11. LIST THREE FUNCTIONS OF THE CELL MEMBRANE (SURFACE) AND BRIEFLY IDENTIFY EXPERIMENTS USED TO DEMONSTRATE THIS. 1. LIST TWO WAYS TO CONTROL FREE CALCIUM CONCENTRATIONS IN CELLS, AND GIVE AN EXAMPLE OF HOW EACH IS USED TO CONTROL CELL ACTIVITIES.

Cell Division 2. CHROMOSOMES CAN MOVE ON AN ISOLATED HALF SPINDLE. WHAT DOES THAT TELL US ABOUT THAT MOVEMENT? 4. DISCUSS SPINDLE FORMATION. .UL CELL PHYSIOLOGY review Receptors 6. CONTRAST STEROID AND PEPTIDE HORMONE RECEPTOR ACTIVATION AND MODULATION 7. HOW CAN cAMP PRODUCED BY THE SAME HORMONE-RECEPTOR INTERACTIONS ELICIT DIFFERENT RESPONSES IN DIFFERENT CELLS? 8. HOW CAN CELLS INFLUENCE MOTILITY OR DIVISION RATE OF OTHER CELLS? 9. WHAT KINDS OF CONTROL MECHANISMS COULD BE DISRUPTED IN CANCER CELLS, SO THEY DIVIDE MORE RAPIDLY AND ARE NOT INFLUENCED BY OTHER CELLS? 3. HOW CAN SECRETION AFFECT A) THE CELL DOING THE SECRETION, B) OTHER CELLS. 8. WHY IS CALCIUM CALLED A SECOND MESSENGER? Nervous System 11. WHAT EVENTS OCCUR AT THE SYNAPSE OF THE POSTSYNAPTIC CELL AT TRANSMISSION? 12. WHAT EVENTS OCCUR AT THE SYNAPSE OF THE PRESYNAPTIC CELL AT TRANSMISSION? 5. IF THE RESTING POTENTIAL IS +20 mV WHAT WOULD BE YOUR GUESS ABOUT THE PERMEABILITIES OF NA AND K THROUGH THE CELL MEMBRANE? 1. WHAT ARE THE COMPONENTS OF A VOLTAGE CLAMP EXPERIMENT, AND HOW HAS THIS TYPE OF EXPERIMENT BEEN USEFUL IN ELUCIDATING CELL MEMBRANE FUNCTION? 2. WHAT IS ONE HYPOTHESIS TO EXPLAIN THE DIFFERENCE OF NA AND K CONCENTRATION INSIDE THE CELL AS COMPARED TO OUTSIDE THE CELL? 3. WHAT KINDS OF FACTORS ARE IMPORTANT IN REGULATING THE ELECTROCHEMICAL POTENTIAL OF THE CELL? 4. WHAT ARE THE DIFFERENCES BETWEEN A RESTING CELL MEMBRANE AND A STIMULATED CELL MEMBRANE AND A RECOVERING CELL MEMBRANE? Vision 2. WHAT IS THE PHYSIOLOGICAL BASIS FOR ONE IMPORTANT DIFFERENCE BETWEEN THE RESTING STATE IN RODS AND CONES AS COMPARED TO NERVE CELLS? 3. WHAT IS A COMMON THEME FOR PROTEINS INVOLVED IN CHANGES OF STATE SUCH AS IN VISION OR CONTRACTION OR CILIARY MOTION? Cell Membrane 6. 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. 9. HOW CAN COATED PITS HELP LARGE MOLECULES TO PASS INTO THE CELL? 10. PRESENT SOME EVIDENCE THAT THE CELL MEMBRANE IS NOT A HOMOGENEOUS MATERIAL ON THE CELL SURFACE. 13. HOW DO YOU KNOW THAT LIPID CONTENT IS IMPORTANT IN MEMBRANE FUNCTION? 11. LIST THREE FUNCTIONS OF THE CELL MEMBRANE (SURFACE) AND BRIEFLY IDENTIFY EXPERIMENTS USED TO DEMONSTRATE THIS. 1. LIST TWO WAYS TO CONTROL FREE CALCIUM CONCENTRATIONS IN CELLS, AND GIVE AN EXAMPLE OF HOW EACH IS USED TO CONTROL CELL ACTIVITIES. Cell Division 2. CHROMOSOMES CAN MOVE ON AN ISOLATED HALF SPINDLE. WHAT DOES THAT TELL US ABOUT THAT MOVEMENT? 4. DISCUSS SPINDLE FORMATION.

REVIEW LAST THIRD BIOL 480

NERVE IMPULSE

1. What is a voltage clamp? How can it be used to separate the effects of Na+ entry and K+ escape? What is the difference between Na+ and K+ leak channels and their voltage regulation. How are voltage regulated channels different from ligand gated channels?

2. What kinds of ion flows are responsible for the various parts of the action potential? What is the basis for the nerve resting potential. How can different kinds of cells have different resting potentials- they are all bathed in similar fluid in the body?

3. Why is Na+K+ATPase important in cell physiology and homeostasis?

4. Which poisons inhibit ion flow? Which drugs prevent nerve transmission? Which drugs mimic neurotransmitters? What does a stimulant do (think back to the movie of slime molds as well)?

5. How is it that acetylcholine can stimulate skeletal muscle but inhibit some smooth muscle and heart muscle? What does nitric oxide have to do with it? How is it formed?

What is the difference between events at the pre- and post-synaptic cells at nerve transmission?

What is an inhibitory neuron doing to a presynaptic cell? What is the effect on the postsynaptic cell?

How does myelin sheath aid nerve conduction?

Myesthenia gravis is an autoimmune disease due to antibodies to actylcholine receptors. What would be the mechanism of the paralysis, do you suppose?

VISION:

What is the physiological basis for one important difference between the resting state in rods and cones as compared to nerve cells? What about the difference at stimulation?

If the resting potential is +20 mv, what would be your guess as to the permeabilities of various cations through the membrane from inside and out?

What is a phosphodiesterase for cGMP doing in vision?

IMMUNE SYSTEM:

Which cells of the immune system have receptors for antigens on their surface and how does the response of receptor-antigen complex get transduced to cell action?

What is the clonal selection theory and how does it explain the immune response to foreign antigens?

What is a mitogen and how is the RAS-gene product related to it? How is G-protein and adenyl cyclase involved?

What is the difference between T- and B-cells? Where are they found, how do they function in the immune system, and how can they interact?

What are antigen-presenting cells, and why are they important?

What is the basis for the myriad of different kinds of antibodies able to be made by the immune system? What is recombinase?

How can cells influence the motility or cell division rates of other cells?

What is the MHC and how is it important in distinguishing self and foreign antigens? What kinds of MHC receptors are there and where are they found?

How can secretion of interleukins affect others cells and the cells doing the secreting? What is the function of a helper cell?

How do killer cells work?

Cancer:

What is an oncogene? What kinds are there? Why are there certain more frequently found types of oncogenes, as compared to others, do you think? What kinds of things are most frequently out of control in cancer cells?

Why do people with AIDS most frequently die of cancer or infection?

What kinds of control mechanisms could be disrupted in cancer cells so they divide more rapidly and are not influenced by other cells?

REVIEW FOR LAST DAY

What have been our main objectives in the course?

To understand how cells do their functions: division, motility, response to stimuli, communication, maintain homeostasis.

To learn what control mechanisms there are for allowing cells to change between different states of the above functions.

This includes membrane cycling, assembly and disassembly of cytoskeleton, synthesis of new material to be incorporated into old. We emphasized those control mechanisms initiated by external factors rather than nuclear control from within as in maintainance and repair.

To recognize the functions of the cell membrane components, cytoskeleton components, cell motor components.

To understand how all of these things are thought to occur at the molecular level by changing which things are bound or released: ions such as H+,Ca+,Mg+, Na+, K+, Cl-; high energy molecules such as ATP, GTP, cAMP, cGMP; extracellulaqr factors such as hormones, growth factors, neurotransmitters, extracellular matrix, antigens or antibodies; level of phosphorylation resulting from cAMP, cGMP, DAG, IP3 production and activation of protein kinases or phosphatases.

So in looking back over this list ask yourself on each part of the sentence How does it work, what controls it, how is important for normal cell function? For example for division in the very first sentence above. How does the cell divide- what machinery is 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 wwhat happens at the molecular level to initiate, to assemble the machinery, to provide energy for the work which is done, to stop when finished.

You should ask these same questions of all topics in the syllabus and ask yourself how they are interrelated. For example how is the membrane involved in each of the topics? Are there receptors involved, ion channels, membrane potentials, G-proteins, lipid breakdown, membrane cycling? How is the cytoskeleton involved in each of the topics? What second messengers and molecular controls are used for each topic?

You see, now we are trying to relate all the topics we have learned about rather than keeping them as isolated compartments of knowledge and that is what the final exam will test, your ability to do that.

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?

5. What do we mean by recognition molecules and how is that related to cell differentiation and how is it related to the immune system?

After you answer these questions try to think of other possible answers. Always have experimental proof of your statements, or examples.