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>.
Digestive enzymes<span> speed up reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive </span>enzymes<span>, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they </span>need<span> to </span><span>survive</span>
the difference in altitude represented by the space between two contour lines on a map. At least i think youre looking for the definition. And if you are hope this helps :)
Fruit flies produce offspring relatively fast and have specific traits, such as eye color and body color/shape. They are easy to observe and their traits are easily traced throughout the next generations.
<span>The correct answer is B) choose the correct lane. It is always important when driving to ensure you are in the correct lane, but in roundabouts, it is essential to the traffic flow. Choice A is not correct because roundabouts are designed to slow down traffic and you need to be paying attention to what is going on and slowing down before you enter. Choice C is not correct because you do not have the right-of-way; the traffic already in the roundabout does and you would need to yield to them. Choice D is not correct because choices A and C are not correct.</span>
