Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
</u>
<u />
Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
Answer:
To show the flow of energy through ecosystems, food chains are sometimes drawn as energy pyramids. Each step of the pyramid represents a different trophic level, starting with primary producers at the bottom. The width of each step represents the rate of energy flow through each trophic level.
Explanation:
Answer: b dead organisms And waste are recycled throughout the tropic levels.
Explanation:
Geo wild card spot on my a open relationship between the two of you are not up for
Passive membrane processes are those that do not require energy and move substances down a concentration gradient; namely, these are diffusion, facilitated diffusion and osmosis.
