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>.
According to science writer Clare Smith for SeattlePi, the cell membrane<span> is kept from</span>collapsing<span> by its phospholipid bilayer, maintenance of the correct temperature, a cytoskeleton and </span>cell<span> junctions. These are necessary because the </span>cell membrane<span> is one of the most crucial components of a </span>cell<span>. Hope it helped!</span>
Because water is so good at storing heat energy, it is harder for organisms to experience a change in body temperature in harsher climates.
Efek amfetamin dosisis tinggi bagi pengguana adalah meant to be letter C.melemabkan kerja otak dan cpt bosan.
