Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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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:
<h2>a rift valley is forming</h2>
Explanation:
Ageing is the word that describes all that change as the organism evolve and it also includes growth !
<span>Hiking in the morning, assuming you have not eaten anything prior to the hike, results in your body having to perform work with lowered glucose levels, thus causing the body to feel out of breath.</span>
I believe it would be an observation
Observation in scientific process refers to gathering facts and information. In this particular context, we could see that the microbiologist is simply stating what he/she saw on the mold on the agar plate. The microbiologist simply writing down all the facts without making any explanation or assumption.
