11. What are the main negative ions found in living beings?
The main anions found in living beings are the chlorine anion (Cl-), the phosphate anion (PO4--), the bicarbonate anion (HCO3-), the nitrate anion (NO3-) and the sulfate anion (SO4-).
12. How do mineral salts participate in osmotic regulation?
Osmotic pressure depends on the number of particles dissolved in a solution and not on the nature of such particles. Mineral salts, glucose, proteins and urea are the main regulating particles for the osmolarity of the organism. These molecules along with other particles inside and outside the cell generate the larger or smaller osmotic gradient between the intracellular and the extracellular space.
13. What is the role of mineral salts in the creation of electric tension (voltage) at the cellular level?
The electric activity of the cell, for example, in neurons, depends on the different concentrations of positive and negative ions between the inner and the outer surfaces of the cell membrane. Mineral salts are responsible for that voltage.
The cell membrane of non-excited cell has commonly a negative inner side and a positive outer side. This electrical situation is maintained by ion transport across the membrane.
14. Why is pH regulation important for living beings? How do mineral salts participate in this regulation?
The potential of hydrogen (pH) is a measure of the amount of hydrogen ions (H-) in a solution. The regulation of the pH according to the necessities of each organ or tissue is extremely important for the organism since enzymes act only under some pH ranges and many proteins are only active under some pH ranges. Therefore biochemical reactions depend on correct levels of pH to occur.
Neutral pH is one of the water properties.
15. How do mineral salts participate in enzymatic activity?
Many mineral salts are cofactors of enzymes, i.e., they are substances without which enzymes do not work.
16. What are the main biological processes in which calcium participates?
Calcium is present in almost all cells and has several functions.
Calcium has an important role in muscular contraction, in the blood coagulation process, in the structure of bone tissue, in teeth, in the motility of the sperm cell flagellum and in the nervous transmission.
17. What is hemoglobin? What is the inorganic element that is fundamental in the composition of hemoglobin?
Hemoglobin is the protein present in the blood responsible for the transport of oxygen from the lungs to the tissues and cells.
The hemoglobin molecule is composed of four protein chains, each with a heme group containing an iron atom. The iron is responsible for the binding of oxygen in the lungs and also for the red color of hemoglobin and thus of the blood.18. What is the importance of magnesium for plants? What are the other main biological functions of magnesium?
Magnesium is fundamentally important for plants because it is part of the chlorophyll molecule (and chlorophyll is essential for photosynthesis).
Magnesium also acts as a cofactor of several enzymes and it is important the muscle relaxation and for the nervous transmission.
19. What is phosphorylation? What are some biological processes in which phosphorylation plays a critical role?
Phosphorylation is the name given to processes of the addition of phosphates to some molecules thus making these molecules more energized. Phosphorylation has an important role, for example, in photosynthesis (the photophosphorylation of the light phase) and in aerobic respiration (oxidative phosphorylation of the respiratory chain). In general the phosphate used in phosphorylation comes from ATP molecules.
20. Why is iodine important for human beings?
Iodine is a fundamental chemical element for the proper functioning of the thyroid since it is part of the hormones produced by this gland. Iodine deficiency creates a kind of hypothyroidism, a disease known as endemic goiter.
21. What are the main biological functions in which chlorine ions participate?
Like sodium cations, chlorine anions actively participate in the regulation of the osmolarity of tissues and cells by crossing the cellular membrane and avoiding entrance of water into the cell or excessive loss of water from the cell. Chlorine anions have an important role for the acid-base balance of the organism since they participate, along with bicarbonate anions, in the pH buffer system of the body. Another function of chlorine is in the digestive physiology: inside the gastric lumen, hydrochloric acid secreted by stomach cells ionizes itself into hydrogen and chlorine ions lowering the pH of the gastric juice and then permitting the enzymatic digestion to take place.
Compiled by My Preparation of Maharashtra Public Service Commission (MPSC) Examination for the blog http://maharashtrapublicserviceexams.blogspot.com
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