(Detailed with complete Questions and Answers)
VERIFIED
Negative Feedback - CORRECT ANSWER - Promotes stability; cancels out the
original response. Ex: High FSBS, increased insulin by the pancreas
Positive Feedback - CORRECT ANSWER - Promotes a change in one
direction; instability, DISEASE. Ex: Blood clotting, platelet cascade
Proteins - CORRECT ANSWER - Provide selectivity to a membrane
Integral proteins - CORRECT ANSWER - channels, pores, carriers, enzymes,
receptors, second messengers
Peripheral proteins - CORRECT ANSWER - Enzymes, intracellular, signal
mediatiors
ATP - CORRECT ANSWER - Converted to ADP to produce energy; chemical
bonds between 2nd and 3rd phosphate groups have abundant energy
Simple/passive diffusion - CORRECT ANSWER - Occurs down a concentration
gradient; from HIGH to LOW concentration
Simple/passive diffusion - CORRECT ANSWER - Diffuse from high to lower
pressure; diffusion will not occur if the membrane is non permeable to the
molecule
Factors that affect the net rate of diffusion - CORRECT ANSWER - 1.
Concentration difference (high to low)
2. Electrical Potential (EMF)- charge difference on each side of the membrane
matters TOO!
3. Pressure difference (higher pressure results in increased energy)
Osmosis - CORRECT ANSWER - Passive transport of fluid across a membrane;
from an area of low solute concentration to high solute concentration (high
FLUID to low FLUID)
Primary Active Transport - CORRECT ANSWER - Molecules are "pumped"
against ("uphill") a concentration; DIRECT USE OF ENERGY
, Secondary Active Transport - CORRECT ANSWER - Trasport is driven by the
energy STORED in the concentration gradient of another molecule (Na+);
INDIRECT USE OF ENERGY
Na+- K+ ATPase - CORRECT ANSWER - Carrier protein located on the plasma
membrane of alll cells; enzyme that converts ATP to ADP to release energy
-Important role in regulating osmotic balance
-Requires one to two thirds of cells energy
Ca2+ ATPase - CORRECT ANSWER - Maintains a low cystosolic Ca2+
concentration
H+ ATPase - CORRECT ANSWER - - Found in parietal cells of gastric glands
(HCl secretion) and intercalated cells of renal tubules (controls blood pH)
- Concentrates H+ ions up to 1 million-fold
Remember: Sodium Potassium Pump - CORRECT ANSWER - sodium is
pumped out of the cell; potassium is pumped in...
Secondary Active Transport; Co-transport - CORRECT ANSWER - Co-
transport: Substance is transported in the same direction as the "driver" ion
(Na+)
Counter transport - CORRECT ANSWER - Substance is transported in the
opposite direction as the driver ion Na+
How do cardiac glycosides increase cardiac contractility? - CORRECT
ANSWER - Increase intracellular Ca2+
ungated Ion Channels - CORRECT ANSWER - determined by size, shape,
distribution of charge
Gated Ion Channels - CORRECT ANSWER - -volgate (e.g.) Voltage dependent
Na+ channels)
-Chemically (e.g. Nicotinic AcH receptor channels)
Ion Channels - CORRECT ANSWER - Conductance depends on probability
that channel is open.
Equilibrium Potential - CORRECT ANSWER - the diffusion potential that
exactly balances or opposes the tendency for diffusion down the concentration
difference.
If a membrane were permeable to only K+ then... - CORRECT ANSWER - K+
would diffuse down its concentration gradient until the electrical potential
across the membrane countered diffusion. (moving from inside the cell down its
concentration gradient to the outside of the cell).