Answer:
The voltage-gated potassium channels associated with an action potential provide an example of what type of membrane transport?
A. Simple diffusion.
B.<u> Facilitated diffusion.
</u>
C. Coupled transport.
D. Active transport.
You are studying the entry of a small molecule into red blood cells. You determine the rate of movement across the membrane under a variety of conditions and make the following observations:
i. The molecules can move across the membrane in either direction.
ii. The molecules always move down their concentration gradient.
iii. No energy source is required for the molecules to move across the membrane.
iv. As the difference in concentration across the membrane increases, the rate of transport reaches a maximum.
The mechanism used to get this molecule across the membrane is most likely:
A. simple diffusion.
<u>B. facilitated diffusion.
</u>
C. active transport.
D. There is not enough information to determine a mechanism.
Carrier proteins - exist in two conformations, altered by high affinity binding of the transported molecule. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLE: GluT1 erythrocyte glucose transporter.
Channel proteins - primarily for ion transport. Form an aqueous pore through the lipid bilayer. May be gated. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLES: Voltage-gated sodium channel, erytrhocyte bicarbonate exchange protein.
This might be helpful... because I don't know anything about facilitated diffusion.
Answer: T T A A G C G G C CA TAA T C T G CTT
Explanation: The A's always pair with T's. The G's always pair with C's.
At first, the population of predators would spike and increase quickly, but then over time, gradually decrease.
(This is because at first there's more food, so the predators population increases. But overtime it begins to level out and the predators' population catches up with the prey, and in result, doesn't continue increasing.)
Explore a wide variety of cells, from bacteria to human neurons, using a compound light microscope. Select a sample to study, then focus on the sample using the coarse and fine focus controls of the microscope. Compare the structures found in different cells, then perform tests to see if the sample is alive.
