Page 30 - 86 human physiology part-2

Nutrition

An energy-yeilding nutrient. Macronutrients are those nutrients that together provide the vast
majority of metabolic energy to an organism. The three main macronutrients are carbohydrates,
proteins, and fat.

Micronutrients
Microminerals or trace elements, are dietary minerals needed by the human body in very small
quantities (generally less than 100mg/day) as opposed to macrominerals which are required in
larger quantities.

Functions

Glucose it is the most easily used by the body. It is a simple carbohydrate that circulates in the
blood and is the main source of energy for the muscles, central nervous system, and is the ONLY
source of energy for the brain.

Carbohydrates are made of organic compounds carbon, hydrogen, and oxygen.

There are three sizes of carbohydrate and they are distinguished by a classification of two that is,
Simple carbohydrates (mono saccharides and disaccharides) and complex carbohydrates
(polysaccharides). Polysaccharides are the most abundant carbohydrate in the body along with
glycogen.

The break down of polysaccharides goes as follows: Polysaccharides are digested into
monosaccchorides including glucose which goes into the intestinal epithelium and into the
bloodstream. The molecules of glucose are taken by glucose transporters and delivered into the cells of
the body. While glucose is in the cells it can be oxidized for energy or provide substrates to other
metabolic reactions or of course into glycogen for storage.

A. Monosaccharides = Single carbohydrate unit, such as, Glucose, Fructose, and Galactose.

B. Disaccharides = Two single carbohydrates bound together these are Sucrose, Maltose, and
Lactose.

C. Polysaccharides = Have many units of monosaccharides joined together such as, Starch and
Fiber.

Proteins

Functions

Protein forms hormones, enzymes, antibodies; it is part of fluid and electrolyte regulation, the
buffering effect for pH, and transporter of nutrients. A good example of a protein is the oxygen
carrying hemoglobin found in red blood cells.

Proteins are made of carbon, hydrogen, oxygen, and nitrogen, an inorganic molecule, the thing
that clearly distinguishes them form the other macronutrients.

A. Amino acids are the building blocks of proteins.

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