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>.
I dont know how old Eli is but here are some
ride a bike instead of driving a car
plant trees
slow down on use of water/electricity
Its that food dropped on the ground is safe to eat and will not be covered in germs as long as its picked up within 5 seconds after its dropped.
The answer to this question would be: parasympathetic division
Parasympathetic nervous is part of the autonomous nervous system. In the autonomous nervous system, the sympathetic system is used when you enter the "fight or flight" mode. In this case, the body will be prepared to be able to take a decision as quickly as possible in a strenuous state. The nervous also cause an increase in the heart and breathing rate to increase body capability.
Parasympathetic is the opposite of it which was activated to calm the body so it can maintain the normal body function.
There are two main theories for the lack of organic material in desert soils. Firstly, the organic life in most deserts is so sparse that it cannot produce much organic matter. Secondly when things do die and decompose in the desert the heat and sunlight often bleach nutrients out of the matter before it is decomposes enough to be absorbed into soil
