Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
</u>
<u />
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:
c
Explanation:
Hubble's brilliant observation was that the red shift of galaxies was directly proportional to the distance of the galaxy from earth. That meant that things farther away from Earth were moving away faster. In other words, the universe must be expanding.
When using High Power Objective Lens, only the Fine Adjustment Knob should be used.
Answer:
Which of the following is FALSE about carbohydrates?
Starch is the storage form of glucose in the body of humans.
Explanation:
Energy is stored by animals as Glycogen and this is achieved through a process called glycolysis
