D. regulates which materials enter and leave the cell
Clean Air Act (CAA), US Federal law, passed in 1970 and later amended, to prevent air pollution and thereby protect the ozone layer and and promote public health. The clean air act gave the federal environmental protection agency the power it needed to take effective action to fight environmental pollution. Hope this helps シ
Answer:
Intercalary meristem is a type of meristematic tissue associated with the growth in length in the middle position, thus the name. In particular, it is made up of meristematic cells that divide mitotically in the stem at the base of nodes and leaf blades. The growth at this point is referred to as intercalary growth.
Explanation:
hopw this helps :)
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.
