Monday, April 30, 2012

Essential Nutrients

Nutrients are chemicals that an organism needs to carry out its life processes.

Out of all the nutrients, many of them need be obtained from our diet. This may be because our bodies do not synthesize enough of these nutrients, or because our bodies do not synthesize thems at all. We call these nutrients essential nutrients, and categorize them into the following: carbohydrates, fats, proteins, minerals, vitamins, and water.

Carbohydrates are made up of carbon, oxygen and hydrogen. They provide a quick source of energy.
Several Types:
  • Monosaccharides: simple sugars (e.g., fructose, galactose, glucose)
  • Disaccharides: sugars made with the condensation reaction between two monosaccharides (e.g, maltose, sucrose, lactose)
  • Polysaccharides: long chains of carbon monomers (e.g., starch, glycogen, cellulose)

  • Make up phopholipid bilayers of cell membranes
  • Surround and protect vital organs and joints
  • insulate bodies
  • Structure: tryglycerides
Saturated vs. Unsaturated Fats: Saturated fats are those where the number of hydrogen atoms are maximized, and unsaturated fats are those that have one or more double bonds between the carbon atoms. Saturated fats are solid at room temperature, and unsaturated fats are liquid at room temperature.

Cholesterol is a soft, waxy lipid in body cells, arteries, veins, and cell membranes. It produces vitamin D, bile acids, and hormones. It can be obtained from meat, shellfish, and egg yolks.

However, too much cholesterol (low density lipoprotein) can be bad, because it can stick to artery walls and cause heart attacks.

  • Has both proteins and lipids
  • Transports fats (triglycerides) and cholesterol in water-based bloodstream

  • Proteins provide structures within the body, and are made up of C, O, N and H
  • Built from a set of 20 amino acids.
  • A complete protein is one that contains all eight essential amino acids (the ones that our body cannot produce)
  • When proteins are taken in, they are broken down into dipeptides and amino acids with the help of digestive enzymes

  • Inorganic molecules that do not contain carbon.
  • They help in chemical reactions, help build bones, cartilages, and hormones
  • Examples
    • Ca- bone formation, nervous signals
    • P-bone formation, build cell membrane, nucleic acids, ATP
    • K- nerve impulse
    • Na- nerve impulse, osmotic balance
    • Fe- hemoglobin synthesis (red blood cells)
    • I- thyroid hormone
    • Cl - water balance,
    • Zn- enzyme synthesis, growth,
    • Se – tissue elasticity, Cu-hemoglobin synthesis

Vitamins are organic molecules that the body need in very small amounts. They serve as coenzymes, assist in tissue growth, and may defend against diseases.

Vitamins can be fat soluble or water soluble:
  • Fat soluble: D, K, E, A
  • Water soluble: B, C (antioxidant)