Answer:
E) Improve membrane fluidity
Explanation:
Cholesterol constitutes the basic structural element of the skeleton of cell membranes. Without their reinforcement, the membranes would become extremely fluid and lose their consistency. Cholesterol is found in the esterified membranes in its hydroxyl group (OH): with fatty acids, mainly oleic and linoleic, or as cholesterol sulfate. The cholesterol-sulfate polar group is disposed on one of the faces of the membrane that interacts with other polar groups in that area, while its bulky hydrophobic portion is embedded between the apolar parts of the lipids that form the membrane skeleton and They fulfill many other functions, among which the reduction in the permeability of protons and sodium ions, and their participation in signal transmission. Cholesterol is also essential in phagocytosis processes carried out by cells to capture many nutrients and, in general, for the function of cleaning up organic waste produced by macrophages.
The membranes must have a fluid structure so that the integrated proteins can move "horizontally" to interact with their ligands and with other proteins. The fluidity is given by unsaturated fat. With the excess of saturated fat, the membranes become rigid, but only with the necessary unsaturated fat the membranes are extremely fluid and very sensitive to temperature changes. Cholesterol stabilizes the structure of the membranes; In order for them to have the correct structure, they must have the correct proportions of saturated, unsaturated fats and cholesterol. The membranes produced in the laboratory without cholesterol are unstable to temperature changes, drastically modifying their fluidity against the small temperature changes that occur in the physiological range.
In addition to its functions in cell membranes, cholesterol is an important product that metabolism uses as a raw material to make other compounds:
*Bile salts
*Sex hormones
*Hormones of the adrenal cortex (corticosteroids)
*Vitamin D (Calciferol)
<span>John can use Cladistic
Analysis as an approach to trace the classifications of the lion and cat
because he can trace a common ancestor for them due to the cat and the lion
having the same characteristics and traits. They are considered to be closely
related because they share a common ancestor which means that they are closely
connected. The earliest discovery of using this method was by Peter Chalmers
Mitchell in 1901 as he was studying how different types of birds belong to the
same ancestry.</span>
photosystem 2, photosystem 1, pumping hydrogen..., and making NADPH
The cytoplasmic streaming can be defined as the movement of the cytoplasm inside the cell. This movement of the cytoplasm helps in the delivery of the metabolites, organelles, and nutrients to all the parts of a cell. The cytoplasmic streaming, which is also known as cyclosis, occurs at the same rate throughout the cell and moves in the direction of the light.
Hence, the answer is 'moves at same rate and towards light'.
