Enzymes differ from chemical catalysts in that each of them affects quite certain substance or a chemical bond of strictly certain type, for example, sucrose catalyzes only sucrose, lactase — lactose etc.
— Optimum temperature for their development is temperature of 40 — 60 °C. At low temperatures enzymes do not collapse, but their action is sharply slowed down, at high (70 — 80 °C and — they are denatured and lose the activity. For enzymes of the person and animals an optimum of action of 37 — 38 °C, i.e. body temperature.
Vitamin A and carotene well remain at thermal treatment of products (5 — 10% collapse). Carotene well remains in fermented and salty vegetables. Losses of vitamin A and carotene in the frozen products are insignificant. Under the influence of light and oxygen of air vitamin A easily collapses.
Vitamin D (calciferol) contains in fat of a liver of fishes, an egg yolk, butter, cheese. Comes to a human body mainly in the form of the ergosterol containing in many foodstuff. At the person is under skin and under the influence of ultraviolet rays turns into vitamin D.
Vitamin E (tocopherol) contains in vegetable oil, germs of cereals (wheat, oats,, salad, peas pods. The shortcoming it in an organism causes frustration of nervous system, malfunction of reproduction in animals.
Vitamin A (Retinolum) contains in fats of sea fishes, beef liver, a yolk of eggs, butter (summer). Vegetable products contain pro-vitamin A — carotene (under the influence of karotinaza enzyme in a human body turns into vitamin. With it carrots, apricots, spinach, green onions, tomatoes are rich.
Except temperature and size Wednesdays influence activity of enzymes various substances which can make active (ions of the various threw or to slow down (for example, hydrocianic acids effect of enzymes.
— Many enzymes are active at neutral reaction of the environment, i.e. at values Wednesdays, close to the physiological. In the sour or alkaline environment they lose the activity, except for some which act in the sour and alkaline environment.
B12 vitamin () contains in a liver, kidneys, dairy products, an egg yolk, etc. Participates in process of synthesis of proteins, promotes formation of red blood little bodies in marrow. Absence it in an organism causes malignant anemia. Daily need for vitamin — 0,002 — 0,005 mg.
The sour environment of a product, starch, table salt detain vitamin C oxidation, promoting its preservation. Rather well vitamin B the fermented vegetables frozen and products preserved in tight container remains.
B6 vitamin (, ) is found in a liver, meat, fish, yeast, haricot, peas, wheat and other foodstuff. Absence it in food breaks processes of transformation of amino acids and causes inflammatory damage of skin. Daily need for vitamin – 2 — 3 mg.
B2 vitamin (Riboflavinum) contains in a liver, beef, an egg yolk, milk. At a shortcoming it in an organism process of oxidation of organic substances therefore the nervous system is weakened is broken, growth stops, there are ulcers in corners of a mouth and a skin peeling, there are a photophobia and lachrymation.