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:
In the natural world, limiting factors like the availability of food, water, shelter and space can change the population of any living organism. Other limiting factors include:competition for resources, predation and disease can also impact populations.
Explanation:
Answer:
living organisms need water to survive. all oxygen-dependent organisms need water to aid in the respiration process; some organisms, such as fish, cannot breathe outside its presence, while other organisms need water to help break down food molecules or generate energy during the respiration process.
Explanation:
water is good
