Answer:
"As a molecule moves through the plasma membrane it passes through <em>a hydrophilic layer of phospholipid heads then a hydrophobic layer of phospholipid tails and then another hydrophilic layer of phospholipid heads".</em>
Explanation:
Biological membranes are formed by two lipidic layers, proteins, and glucans.
Lipids characterize for being amphipathic molecules, which means that they have both a hydrophilic portion and a hydrophobic portion at the same time. These molecules have a lipidic head that corresponds to a negatively charged phosphate group, which is the polar and hydrophilic portion. They also have two lipidic tails that correspond to the hydrocarbon chains -the apolar and hydrophobic portion- of the fatty acids that esterify glycerol.
Membrane lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other, which happens because of concentration differences. When this occurs, molecules must pass through the hydrophilic layer of phospholipid heads then through the hydrophobic layer of phospholipid tails and then again through another hydrophilic layer of phospholipid heads.
Answer:
Renal cortex
Explanation:
The renal medulla of a kidney is surrounded by renal cortex. The renal cortex is the granulated layer. It is the renal cortex in which the renal corpuscle (glomerulus and Bowman's capsule) are present. The renal cortex is reddish brown in color. This is due to the fact that most of the renal arteries deliver the blood to the cortex.
Answer:
When an organism excretes or dies, nitrogen is in the form of organic nitrogen in its tissues (e.g. amino acids, DNA). During the ammonification process, many fungi and prokaryotes then break the tissue down and release inorganic Nitrogen into the atmosphere as ammonia.
Explanation:
Plants use their roots for nitrogen compounds. When they consume the seeds, animals acquire certain chemicals. When plants and livestock die, or animals excrete waste, the organic nitrogen compounds return to the soil, where microorganisms known as decomposers break down their compounds.
