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>.
The plates will move and the underwater island will start to move and shift. It's possible it will also weather
Photosynthesis and cellular respiration are opposites
In DNA, there is a code for the sequence
of three bases for the placement of certain amino acid in a protein chain.<span> The amino acid chain that can be produced by
the DNA base sequence of C-A-A-G-T-T-A-A-A-T-T-A-T-T-G-T-G-A would be based on
the DNA code CAA is valine, GTT is glutamine, AAA is phenylalanine, TTA is asparagine,
TTG is asparagine and TGA is threonine. </span>
