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.
Migration i think is the answer
Answer:
D. the dynamic regulation of an organism's internal environment to maintain conditions suitable for survival.
Explanation:
Answer:
If the immune system has a destructive and autoimmune response, it produces specific antibodies, which bind to the receptors of the thyroid cells and destroy them thinking that they are antigens or factors not characteristic of the body.
Explanation:
This happens because the thyroid cells do not present on its surface the histocompatibility complex, which is a surface protein similar to the proper and non-proper "seal", that is, it is the demarcation by which the antibodies and the cells are guided to recognize what foreign to the organism.
The histocompatibility complex is sometimes absent or rather mutated, thus generating that these cells are considered not their own and that the antibody is a receptor in order to generate the autolysis pathway or even the immune defense pathway.
