Lecture Notes for Weds Dec 3, 2003

Enzymes: Purpose? Active site? Substrate?

http://www.sirinet.net/~jgjohnso/enzymes.html

Vitamins:

Most vitamins are not produced by the body and must be obtained from the diet. Only small amounts are needed.

Function: Serve as co-enzymes.

Classification: Water Soluble or Fat Soluble

Water soluble can be excreted in the urine. If an individual takes a surplus of water soluble vitamins it can be eliminated from the body.

Water-soluble vitamins consist of: members of the vitamin B complex and vitamin C. They are generally found together in the same foods with the exception of B₁₂ which is present only in meat and dairy foods. The others are found in whole grain cereals, legumes, leafy green vegetables, and fruits. The water-soluble vitamins generally function to assist the activity of important enzymes such as those involved in the production of energy from carbohydrates and fats. They are often referred to as "cofactors".

Fat Soluble Vitamins

Fat Soluble Vitamins cannot be excreted in the urine and toxicity can occur if there is excess of fat soluble vitamins taken, since fat soluble vitamins would be stored in fat cells.

Fat Soluble Vitamins consist of: Vitamin A, D, E and K.

Fat soluble vitamins are found in: meats, liver, dairy, egg yolks, vegetable seed oils, and leafy green vegetables. Some foods such as milk and margarine are artificially fortified with vitamins A and D.

Health Protectors:

Antioxidants – chemicals that disarm cell damaging molecules called free radicals. Antioxidants donate their electron to the outershell of the free radical.

Free radicals – unstable, highly reactive byproducts of cell respiration that can damage cell proteins and nucleic acids. They are reactive chemicals with unpaired electrons that scramble the structure of polymers.

Sources: Vitamins A, C, Beta carotene and E.

Minerals:

Macrominerals (more than 100 mg/day needed)

Include: Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chloride, Magnesium

MicroMinerals (less than 20 mg/day needed)

Zinc, Iron, Copper, Iodine, Selenium, Manganese

Water

Contributes to 60-70% of body weight.

Solvent in which chemicals dissolve, transport chemicals through the body, provides a medium in which chemical reactions takes place, important in temperature regulation.

Need 2-3 liters a day.

Eating Disorders:

Please check the website out for additional information regarding eating disorders. The most serious health problem associated with individuals that suffer from Anorexia Nervosa is a heart attack.

Ulcers:

Over 95% of the ulcers are due to Helicobacter pylori (H. pylori) bacteria. Causes a ulcer (sore) in the stomach lining or the lining found in the first part of the small intestine.

Hepatitis A:

A viral liver disease, which causes your liver to swell and keeps it from functioning properly.
It is caused by fecal – oral contamination. It can make you feel like you have the flu. Some people have dark yellow urine, light colored stools and yellowish skin and eyes.

Most people will recover in a few weeks.

Foodborne Illnesses:
The Centers for Disease Control and Prevention (CDC) estimates that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year.

Foodborne Illness

Staphylococcal – Most common food poisoning, releases several enterotoxins. Severe reaction occurs within 1-6 hrs of ingesting food containing toxin. Nausea, vomiting, and diarrhea.

Source: custards, poultry, meat, puddings, salad dressings, egg and meat salad. Outdoor summer picnics.

Salmonellosis – Symptoms arise after the pathogen has grown in the intestine for several days.

Headache, chills, vomiting and diarrhea. Followed by a fever that lasts for a few days.

Source: meat and meat products, poultry, egg and milk products.

Echerichia coli

E.coli 0157:H7
Causes at least 20,000 cases a year and 250 deaths.

Bloody diarrhea

Source: uncooked or under cooked meat.

Five pathogens account for over 90% of the estimated food related deaths:

Salmonella 31%

Listeria 28%

Toxoplasma 21%

Norwalk- like virus 7%

Campylobacter 5%

E. coli 0157:H7 3%

Diarrhea

World wide, over half of child deaths (<4 yrs) are due dehydration caused by diarrhea.
Colon becomes irritated, peristalsis increases and chime moves rapidly through the colon, preventing adequate absorption. Results in liquid feces.

Loose valuable ions which can cause dehydration.

Traveler’s Diarrhea

Caused by ingesting unfamiliar bacteria. May cause diarrhea until these new bacteria become established as part of your normal flora.