|The sources of protein |
(a and b animal)
(c and d plant)
There are 20 types of amino acids that are classified into two part, essential amino acid an non-essential amino acid and non-essential amino acid.
- Essential amino acid is very necessary and not synthesis by body. It is only synthesized by plant, such as lysine, tryptophane, phenylalanine, leusine, isoleusine, treonin, metionin, valine, arginine, and hystidene.
- Non-Essential amino acid is the amino acid that can be synthesized by body, such as alanine, aspargine, aspartic acid, glutamic acid, glysine, glutamine, proline, serine, systein, cystine, and tyrosine.
Protein has many advantages for body because it has several function as follows.
- As a body builder substance. Including growth, maintenance, and reparation of body structure (cell, tissue, and organ).
- Synthesizing essential substances, i.e. hormone, enzyme, and antibody.
- Maintaining the balance of body liquid, alkalinity and acidity of solution, pressure in the constriction of body cavity, and becoming an effective buffer system.
- Providing energy source (1 gram protein produces 4.1 calorie).
- Detoxificating foreign materials that enter the body.
We can obtain protein from animal (animal protein) or plant (vegetable protein). Sources of animal protein are fish, meat, milk, and egg, while sources of plant protein are grains, nuts, and vegetable.
The average standard of protein sufficient in a day is 45 grams. Deficiency of protein causes kwashiorkor. The requirement level of protein is influenced by body weigh and size, age, sex, disease, denomination of nutrition, body, condition, protein characteristic that we eat, pregnancy (breastfeeding) period, and emotional status.
source biology 2004