Lecture 03-04 Flashcards
Six classes of nutrients:
Carbohydrates Lipids Proteins Minerals Vitamins Water
Nutrients three jobs?
- Provide energy
- Form new body components
- Assist in various physiological functions/processes
Metabolism:
all chemical reactions that occur in the body
Anabolism:
combining smaller molecules into larger ones.
Catabolism:
breaking large molecules into smaller ones with release of energy.
Enzymes:
proteins that act as catalyss to sdpeed up chemical reactions.
Sugars, primary one used by body is
glucose
polysaccarides)
Stored in body as long chains called glycogen in liver and muscle cells.
Monosaccarides (short)
Monosaccarides (short) – from fruits and sugar cane.
Polysaccarides
from grains and vegetables
LIPIDS
many hydrogen bonds, so lots of stored energy
Triglycerides
storage
Phospholipids
cell membranes, myelin sheaths
Steroids
(e.g. cholesterol) – modified to become hormones and bile secretions (from liver). Excess stored in adipose tissue.
PROTEINS
Many functions: structural, transport, cell movement, enzymes, specialized functions such as hemoglobin)
Made up of amino acids (20 types)
During digestion, broken down to individual amino acids
Can be later rebuilt.
Liver can convert excess amino acids to triglycerides.
Large excess of amino acids lost in urine.
MINERALS
Inorganic nutrients required in small amounts
About 4% of total body weight (mostly in skeleton).
Macrominerals (needed at levels of over 100 milligrams a day): Calcium, Phosphorus, Sulfer, Sodium, Potassium, Chlorine, Magnesium
Microminerals (needed in only trace amounts): Iron,l Iodine, Copper, Zinc, Floourine, Manganese, Cobalt, Chromium, Selenium
VITAMINS
Do not provide energy or building materials, but act as co-enzymes (necessary for enzyme functions) Fat Soluble (absorbed with lipids in small intestine; can be stored in cells): A, D, E, K Water Soluble (absorbed with water in large intestine; excess excreted in urine, not stored): B, C, Pantothenic acid, Folic acid, Biotin
Fat Soluble
(absorbed with lipids in small intestine; can be stored in cells): A, D, E, K
Water Soluble
absorbed with water in large intestine; excess excreted in urine, not stored): B, C, Pantothenic acid, Folic acid, Biotin
METABOLISM
sum role of all cellular activities that maintain the body.
DIGESTION:
mechanical and chemical processes involved in breaking larger food particles down into smaller ones.
ABSORPTION:
process by which these (resulting) molecules pass from the gut tube to the bloodstream and lymphatic circulation.
MOUTH, Mechanical Digestion:
chewing (teeth), manipulation of food by muscles of mastication (V3), buccinator (VII), and tongue (XII)
MOUTH,Chemical Digestion:
salivary amaylase (initial carbohydrate breakdown) – starch breakdown