Bacterial 'battle for survival' leads to new antibiotic -- Holds promise for treating stomach ulcers. A press release from MIT, Feb 2008, on a new approach for discovering new antibiotics. Briefly, they force bacteria not known to make antibiotics to compete with other bacteria. One possible response is for them to develop the ability to make antibiotics. This should be considered interesting lab work at this point. The potential of the new antibiotics is unknown. web.mit.edu/newsoffice/2008/a...tics-0226.html.

1. What is the relationship between vitamin D and sunlight?

2. What disease is caused by vitamin D deficiency? Which tissue does it affect?

3. What is the function of vitamin E? In which foods can it be found?

4. Why are some types of hemorrhagic diseases caused by a genetic or acquired inability to metabolize vitamin K?

5. What are the functions of biotin and pantothenic acid in the body? How are these vitamins obtained?

6. What are the main mineral salts responsible for cellular osmotic regulation?

7. What are the main cellular functions of potassium?

8. What are some examples of mineral salts from the diet that act as coenzymes?

9. What disease is caused by dietary iodine deficiency?

10. What is the importance of iron in the diet? What disease is caused by iron deficiency?

Answer:

1 Vitamin D, or calciferol, is synthesized in the skin through the actions of the ultraviolet range of sunlight on precursor molecules. Later, it is transformed into its active form in the liver and the kidneys.

2 The lack of vitamin D causes the disease known as rickets (rachitis), which is characterized by the decalcification of bones and bone deformities. Vitamin D is fundamental for the absorption of calcium and, as a result, it is related to bone tissue health. 

3 Vitamin E, or tocopherol, is a fat-soluble vitamin that is involved in the respiratory chain as coenzyme, during final stage of aerobic cellular respiration. Its deficiency may cause sterility, spontaneous abortions and muscle dystrophy.
Vitamin E is mainly found in corn oil and peanut oil, wheat germ, milk, eggs and leafy vegetables.

4 Vitamin K deficiency predisposes people to hemorrhages since this vitamin is necessary for the formation of prothrombin during the blood clotting process.

5 Biotin (also known as vitamin B8) is a vitamin that is involved in the metabolism of amino acids and other acids. Pantothenic acid (also known as vitamin B5) is important for aerobic cellular respiration, since it is involved in the transport of acetyl and acyl radicals.
Biotin is made by bacteria that live in the human digestive tract (in a interspecific harmonious ecological interaction) and this supply in general is enough for the body. Biotin and pantothenic acid are found in vegetables, grains, eggs, fish, milk and lean meat.

6 The main ions that are involved in the regulation of the osmotic pressure in cells and tissues are the chlorine anion, the sodium cation and the potassium cation.

7 Besides being important for osmotic regulation and for the acid-base equilibrium (pH), potassium is necessary for the excitatory mechanisms of nerves and in muscle contraction.

8 Magnesium, zinc and copper are examples of biological coenzymes.

9 Iodine deficiency causes hypothyroidism, an abnormally low production of thyroid hormones, which need iodine to be synthesized.

10 Iron is a component of the hemoglobin molecule and of enzymes involved in digestion and energy metabolism. Dietary iron deficiency causes iron deficiency anemia, an abnormally low hemoglobin concentration in the blood due to the lack of iron. (In pregnancy, the fetus consumes a large amount of iron and this can lead to anemia.)