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>.
Having the occasional alcoholic drink is unlikely to affect your fertility. But heavy drinking and smoking can reduce sperm quality, lower testosterone production, and make it harder to achieve an erection. It can also lead to liver damage, which affects both your general and reproductive health
A. Alleles lineup independently of the other alleles
Answer:
Why does the amount or dose entering the body matter? ... A point would be reached where beneficial effects would disappear and harmful effects would start to be noticed. ... harmful is directly related to the amount of it taken into the body at one time. ... Chemicals with high toxicity only need small doses to cause poisoning.
Explanation:
