exam 1 review

Question 1

what is the difference between +/- feedback? examples of both.

Answer 1

positive feedback causes an increase in the rxns and will not stop until a force is acted upon it( delivering a baby), negative feedback tries to get the rxn to stop (high BP dilates blood vessels to lower BP)

Question 2

Plasma membrane

Answer 2

has lipid bilayer which divides intracellular and extracellular space

Question 3

proteins in the plasma membrane 2.5 types

Answer 3

Integral (transmembrane) and peripheral

Question 4

fxns of membrane proteins 7

Answer 4

1. Receptors 2. second msngr systems 3. enzymes 4. channel proteins 5, carriers 6. cell identity markers (glycocalyx) 7. cell-adhesion markers

Question 5

how do channel proteins differ

Answer 5

some are always open while others are gates

Question 6

types of gated channel proteins?

Answer 6

ligand gated, voltage gated and mechanical gated.

Question 7

Tonicity means

Answer 7

the affect a solution has on fluid volume and pressure of cell

Question 8

examples of tonicity are

Answer 8

Hypotonic, Isotonic and Hypertonic

Question 9

blood plasma has an osmolarity of .45%, 0.9% or 2.0% how would RBC’s react

Answer 9

1. cell will burst/lyse (hypertonic) 2. cell will remain isotonic 3. cell will shrivel/crenate (hypotonic)