Phrx 308 Exam 1 2011 (P1) Outline 1

Front 1

Describe the general composition of the cell membrane.

Back 1

Phospholipid bilayer. Hydrophobic lipid tails project inward. Hydrophilic polar phospho- heads project on the outside surface.

Front 2

What are the major functions of membrane proteins?

Back 2

Transport (channels or carriers, enzymes, or receptors.

Front 3

What is the origin of prostoglandins, thromboxanes, and leukotrienes?

Back 3

An enzyme can break phospholipid bonds releasing fatty acids which are converted into those bioactive molecules.

Front 4

What do prostoglandins, thromboxanes, and leukotrienes cause and how are they affected by aspirin and ibuprofen?

Back 4

Prostoglandins- Inflammation
Thromboxanes- blood clotting
Leukotrienes- inflammation in airways.
Aspirin and Ibuprofen decrease their production.

Front 5

Name 4 mechanisms by which solutes can enter cells.

Back 5

Passage through the lipid bilayer, carriers (transport proteins), Leak channel, and gated channel.

Front 6

Describe the passage through the bilayer.

Back 6

No energy is needed and charged particles can not pass.

Front 7

Describe the carrier (transport protein) method.

Back 7

substance or one side of the membrane binds and causes conformational change to open to the other side; moves SOLUTES; may or may not require ATP.

Front 8

Describe passage through a leak channel.

Back 8

Usually stays open; permits continuous movement of water or ions. No energy needed.

Front 9

Describe passage through a gated channel.

Back 9

Closes and opens to regulate the movement of ions.

Front 10

What are the different types of epithelial cells?

Back 10

Exchange, transporting, ciliated, protective, and secretory.

Front 11

Describe exchange epithelial cells.

Back 11

One cell layer; pores between cells permit easy passage of molecules; found in blood vessels

Front 12

Describe transporting epithelial cells.

Back 12

One cell layer; tight junctions prevent movement b/t cells; surface area increased by folding of cell membrane into villi (fingers); found in the kidney and GI

Front 13

Describe ciliated epithelial cells.

Back 13

One cell layer; one side covered with cilia to move fluid across the surface; found in airways, nasal passages, female reproductive tract.

Front 14

Describe protective epithelial cells.

Back 14

Many cell layers; cells tightly connected by many desmosomes; found in the skin

Front 15

Describe secretory epithelial cells.

Back 15

one to many cell layers; protein secreting cells filled w/ membrane- bound secretory granules and extensive RER (protein synthesis) steroid secreting cells contain lipid droplets and extensive SER (lipid synthesis); found in endocrine glands (pancreas) and exocrine glands (sweat glands).

Front 16

Name the different types of connective tissue.

Back 16

Loose CT, Dense-Irregular CT, Dense-regular CT, adipose, blood, cartilage, and bone.

Front 17

Describe Loose connective tissue.

Back 17

fiber types: collagen, elastic, reticular.
arrangement: random
main cell types: fibroblasts
found: around organs

Front 18

Describe dense- irregular connective tissue.

Back 18

fiber types: mostly collagen
arrangement: random
main cell types: fibroblasts
found: in sheaths around muscles

Front 19

Describe dense- regular connective tissue.

Back 19

fiber types: collagen
arrangement: parallel
main cell types: fibroblasts
found: tendons and ligaments

Front 20

Describe adipose tissue.

Back 20

fiber types: none
arrangement: none
main cell types: brown and white fat

Front 21

Describe blood tissue.

Back 21

fiber types: none
arrangement: none
main cell types: blood cells

Front 22

Describe cartilage tissue.

Back 22

fiber types: collagen
main cell types: chondroblasts

Front 23

Describe bone tissue.

Back 23

fiber types: collagen
main cell types: osteoblasts and osteoclasts

Front 24

Name the 3 types of stem cells.

Back 24

Totipotent, pleuripotent, and multipotent.

Front 25

Define totipotent stem cells.

Back 25

the zygote and the first 4 cells produced by its cleavage can differentiate into ANY type of specialized cell found in the adult body and extra-embryonic membranes.

Front 26

Define pleuripotent stem cells.

Back 26

can differentiate into MOST cell types in the body and are isolated from embryonic and fetal tissue.

Front 27

Define multipotent stem cells.

Back 27

remain after birth and can differentiate into a limited number of cell types. Ex: bone marrow can give rise to all blood cells but not other types.

Front 28

Define homeostasis.

Back 28

the ability of the body to maintain a relatively constant internal environment.

Front 29

Define equilibrium.

Back 29

a state of rest or balance due to the equal action of opposing forces.

Front 30

In health we exist in a state of __, __, __, and __.

Back 30

homeostasis, chemical disequilibrium, electrical disequilibrium, osmotic equilibrium.

Front 31

Why are we in a state of chemical disequilibrium?

Back 31

solute concentrations differing in the different compartments.

Front 32

Why are we in a state of electrical disequilibrium?

Back 32

electrical charge differing in the different compartments.

Front 33

What are the extracellular concentrations of (assume superscript of charges) Na+, K+, Ca++, and Cl- ? State whether they are at greater concentrations in the extracellular or intracellular compartments.

Back 33

Na+= 145 mmol/ L; Extra
K+= 5 mmol/ L; Intra
Ca++= 2.4 mmol/ L; Extra
Cl-= 103 mmol/ L; Extra

Front 34

What are some factors the affect diffusion?

Back 34

Surface area, concentration gradient, membrane permeability, membrane thickness

Front 35

How do the diffusion factors affect topical drug absorption?

Back 35

to increase the amount of drug diffused across the skin; spread over a larger area, put more on, or put on an area of thinner skin.

Front 36

Gated channels are usually closed. what are the different types of channel gating?

Back 36

Chemical (ligand gated), Electrical (voltage gated), Mechanical signals.

Front 37

Describe a chemically gated channel.

Back 37

Gates open because of a ligand binding the correct receptor.

Front 38

Describe an electrically gated channel.

Back 38

changes of voltage on the membrane open or close the gate.

Front 39

Describe a mechanically gated channel.

Back 39

physical stretching or a response by a touch receptor on the skin opens the gate.

Front 40

What are the characteristics of carrier mediated transport?

Back 40

1. carriers are specific
2. carriers display saturability due to limited availability
3. some carriers can be regulated
4. can be energy independent (facilitated diffusion) or dependent (active transport)

Front 41

Differentiate between uniporters, symporters, and antiporters.

Back 41

uniporters- transport only ONE kind of substrate.
symporters- move two or more substrates in the same direction across the membrane.
antiporters- move substrates in opposite directions.

Front 42

What is the difference in passive and active transport?

Back 42

Passive: allows mov't of molecules down the conc. gradient. No energy. (Ex. simple diffusion, channels, and carriers)
Active: allows mov't up the gradient. requires energy directly or indirectly from ATP. (Ex. Na+/ K+ pump)

Front 43

What is the difference between primary and secondary active transport?

Back 43

Primary active transport: uses ATP hydrolysis directly for energy to move molecules up the gradient. (Ex. ATPase pump)
Secondary active transport: uses potential energy stored in a concentration gradient of one molecule to move another molecule up the gradient. (Ex. Na+/ glucose co-transporter)

Front 44

Name types of substances transported into the cell by receptor mediated endocytosis.

Back 44

Protein hormones, growth factors, and cholesterol.

Front 45

How are transporting epithelial cells polarized?

Back 45

They are different on either side of the cell.

Front 46

What is the difference in absorption and secretion?

Back 46

Absorption: route by which substances enter (exterior --> interior)
Secretion: process of releasing substances from the cell (interior --> exterior)

Front 47

Why are sodium and glucose present in fluids used to rehydrate people that have experienced major dehydration from profuse diarrhea?

Back 47

The glucose helps get the transporter to take in Na+

Front 48

How would you calculate a solutions' osmolarity when given its molarity?

Back 48

(Molarity)(# of particles)/ molecules = osmolarity

Front 49

What is the difference in osmolarity and tonicity?

Back 49

Osmolarity: reflects the number of particles in a solution
Tonicity: measure of the osmotic pressure gradient of two solutions seperated by a semi-permeable membrane and depends on non-penetrating solutes. (describes how a solution affects cell volume)

Front 50

How is cell volume effected by a solutes molarity?

Back 50

1. if the cell has a high conc. of non-penetrating solutes water will move into the cell (hypotonic solution) (cell will swell)
2. if the cell has a lower conc. of non-penetrating solutes water will move out of the cell (hypertonic solution) (cell will shrink)
3. If the cell and solution have an equal number of non- penetrating solutes no movement of water will occur. (isotonic solution)

Front 51

Know how to calculate an ion's equilibrium potential when given the Nerst equation and its intracellular and extracellular concentrations.

Back 51

Pg. 17+18 in notes

Front 52

What does the equilibrium potential represent?

Back 52

if we know the concentration of an ion on the inside and outside of the cell membrane we can calculate the exact electrical potential that will balance the chemical drive for that ion to move.

Front 53

Be able to determine the direction an ion will move (intracellularly or extracellularly) if a channel for that ion is open.

Back 53

Pg. 18 in the notes

Front 54

What are the different mechanisms of cellular communication?

Back 54

electrical of chemical signals. 1.gap junctions
2.direct contact signaling.
3.secreted chemicals that interact with cell receptors. (NT, hormonal, paracrine, autocrine, neuroendocrine)

Front 55

What are different ways chemical signals can be transduced into cellular responses?

Back 55

1. channel regulation
2. alters protein kinase activity or influences a signaling that produces 2nd messenger.

Front 56

What are the categories of membrane receptors?

Back 56

1. ligand gated channel (ligand binding opens and closes channel)
2. receptor- enzyme (ligand binding receptor activates an intracellular enzyme)
3. G protein coupled receptor (ligand binding a G protein coupled receptor opens an ion channel or alters enzyme activity)
4. Integrin receptor (ligand binding to integrin receptor alters the cytoskeleton)

Front 57

Describe steroid hormone receptors.

Back 57

Intracellular receptors which initiate signal transduction for steroid hormones.

Front 58

Steroid hormones include ___ and ___.

Back 58

estrogen, cortisol

Front 59

Steroid hormones effect gene ___ and therefore effect ___ expression.

Back 59

transcription, protein

Front 60

Can one signaling molecule have separate effects in different tissues? if so, why?

Back 60

Yes. Depends on the receptor. There can be multiple receptors for one molecule, resulting in multiple effects.

Front 61

What is the difference in a receptor agonist and antagonist?

Back 61

Agonist: if a ligand binds the receptor it results in a response. (activates receptor)
Antagonist: if a ligand binds the receptor a response is prevented. (blocks receptor activity)

Front 62

Describe receptor up and down regulation.

Back 62

Up regulation: an increase in the # of receptors on the surface of target cells, making the cell more sensitive to a hormone or another agent.
Down regulation: decrease in the # of receptors on a cell surface; reduces the cell's sensitivity to the molecule.

Front 63

Name mechanisms by which a chemical signal can be terminated.

Back 63

1. closing the gate
2. sequestor ion in intracellular stores
3. breakdown signaling molecule
4. remove signaling molecule- reuptake
5. endocytose receptor ligand complex
6. alter receptor to turn it off

Front 64

What are 3 major factors that determine resting membrane potential (RMP)?

Back 64

1. K+ conductance through a leak channel.
2. Na+/K+ ATPase activity (makes inside more negative)
3. Small conductance of Na+ thru leak channel (makes RMP less negative)

Front 65

What are mechanisms by which changes in membrane potential occurs?

Back 65

1. Changes in membrane permeability
2. opening or closing specific membrane channels (gated channels)

Front 66

What is the difference in graded potentials and action potentials?

Back 66

Graded potentials: temporary local change in resting caused by a stimulus; loses strength through the cytoplasm.
Action potential: an electrical impulse produced by a graded potential that propogates along the surface of an axon to the synapse; affects the entire excitable cell membrane.

Front 67

List the events that occur at each stage of the action potential and the changes in membrane potential.

Back 67

1. RMP (-70mV)
2. Depolar. of threshold (-55mV)
3. Na+ in (0mV)
4. Na+ closing, K+ opening (+30mV)
5. K+ out (0mV)
6. hyperpolarization (-90mV)
7. leak channel activity (gates channels closed) (-70mV)

Front 68

What are the differences in Absolute and Relative refractory periods?

Back 68

Absolute: coincides w/ nearly the entire duration of the AP; interval during which a second action potential absolutely CAN NOT be initiated.
Relative: immediately follows the absolute; interval during which initiation of a second action potential is INHIBITED but NOT IMPOSSIBLE.

Front 69

What is Saltatory conduction?

Back 69

The propagation of APs along myelinated axons from one node of Ranvier to the next node.

Front 70

Why does saltatory conduction increase the conduction velocity of APs?

Back 70

1. Myelin sheath provides insulation that prevents ion flow
2. Myelin sheath interrupted by nodes of Ranvier.
3. AP generated only at nodes of Ranvier.

Front 71

What are the effects of hypokalemia and hyperkalemia on RMP?

Back 71

Hypokalemia: Low K+ in blood; membrane becomes hyperpolarized and harder to stimulate (muscle weakness)
Hyperkalemia: High K+ in blood; membrane becomes depolarized; (heart arrhythmia, muscle weakness)

Front 72

What happens at the synapse when AP reaches the axon terminal?

Back 72

1. AP depolarizes the nerve terminal
2. Ca++ channels open (voltage gated)
3.vesicle empties NT into synapse
4. NT binds the receptor on post synaptic cell.
5.Response

Front 73

What is the difference in Isonotropic and metabotropic receptors?

Back 73

Isonotropic: A chemically gated ion channel allows ions through; rapid, short synaptic potential.
Metabotropic: receptor which binds a chemical that generates a response; long, slow synaptic potentials.

Front 74

Describe events that occur at the NMJ

Back 74

1. Reuptake of NT (neurocrine)
2. Enzyme breakdown of NT
3. Diffuses away