2. Chemical Digestion Basics
• Dehydration Synthesis vs. Hydrolysis
• Anabolic – Dehydration Synthesis
– Require the removal of water to form bonds
• Catabolic – Hydrolytic Reactions
– Require the addition of water to break bonds
• Carbohydrates – mono and disaccharides
• Lipids (triglycerides) – glycerol + fatty acids
• Proteins – amino acids
7. Factoids:
Enzymes:
• Turnover numbers are very high
• Examples:
– 1 molecule of acetylcholinesterase ->
25,000 molecules of acetylcholine in 1
second
– 1 molecule of catalase breaks down 40
million molecules of hydrogen
peroxide in 1 second
9. Factoids:
Enzymes:
• Sometimes require a
nonprotein factor =
cofactor (metallic ion)
or coenzyme (vitamin)
– Examples:
• Iron, zinc, copper,
sodium, potassium,
vitamin B
10. Factoids:
Enzymes:
• are usually named
after the substrate on
which they act
• have names ending in
–ase ( with a few
exceptions)
Examples:
• Cellulase
• Sucrase
• Lipase
• Lactase
• Acetylcholinesterase
21. Questions Concerning Dietary
Enzyme Supplements
• Are there people who do not produce
enough of certain enzymes?
• Could an increase in digestive enzymes
increase the digestion of food?
• Can you increase the amount of digestive
enzymes by taking oral dietary
supplements?
Editor's Notes
Acids and Bases: Enzyme activity is also controlled by pH. As the pH is decreased or increased, the nature of the various acid and amine groups on side chains is altered with resulting changes in the overall shape structure of the enzyme.
Specific Inhibitors:
Specific Inhibitors exert their effects upon a single enzyme. Most poisons work by specific inhibition of enzymes. Many drugs also work by inhibiting enzymes in bacteria, viruses, or cancerous cells.
Competitive Inhibitors:
A competitive inhibitor is any compound which closely resembles the chemical structure and molecular geometry of the substrate. The inhibitor competes for the same active site as the substrate molecule. The inhibitor may interact with the enzyme at the active site, but no reaction takes place. The inhibitor is "stuck" on the enzyme and prevents any substrate molecules from reacting with the enzyme. However, a competitive inhibition is usually reversible if sufficient substrate molecules are available to ultimately displace the inhibitor. Therefore, the amount of enzyme inhibition depends upon the inhibitor concentration, substrate concentration, and the relative affinities of the inhibitor and substrate for the active site.
Gelatin is made from a protein called collagen which comes from the joints of animals. Gelatin may be dissolved in hot water. As the dissolved gelatin mixture cools, the collagen forms into a matrix that traps the water; as a result, the mixture turns into the jiggling semi-solid mass that is so recognizable as Jell-O™.
Pineapple belongs to a group of plants called Bromeliads. Kiwi, papaya, and figs are other types of Bromeliads. Pineapple contains an enzyme (bromelain) that breakdowns the of collagen. Fresh pineapple cannot be used in making Jell-O…it does not gel because the collagen is destroyed.
The process of canning pineapple denatures the bromelain, rendering it incapable of catalyzing the break down of gelatin. So if you are making jello with pineapple, you have to use canned pineapple.
CLAIM:
Enzymes are the spark of life! They are energized protein molecules made by all plant and animal cells. They catalyze, which means they make chemical reactions go faster, and regulate most biochemical reactions that occur within the human body.
FACT:
Enzymes are proteins but are not "energized." The enzymes that help regulate biochemical reactions in body cells are made by the body and cannot be supplied by plant enzyme pills. Nu-Zymes contains the enzymes that your body may no longer be producing and that you may not be getting from the food you eat. Few if any people stop producing enzymes. Regardless, the enzyme content of foods has no significance because such enzymes are digested and do not function within the body.
CLAIM:
Poor dietary habits, fast food, and excessive intake of fat and sugar, all require excessive amounts of enzymes. Stress damages and even kills cells, resulting in our enzyme-making machinery having to work overtime to help rebuild and replace them. Environmental pollution causes continuous cellular damage requiring ongoing assistance from enzymes to maintain a healthy immune system.
FACT:
Every one of these statements is absurd.
CLAIM:
The modern diet consists predominately of enzyme-deficient cooked foods. Most Americans eat too few raw fruits and vegetables which are excellent sources of enzymes. However, enzymes are destroyed when food is processed, canned or cooked. Supplementation of enzymes can replace some of those lost in cooking and enhance enzymes found in raw foods.
FACT:
The amount of enzymes in food has no health significance because plant enzymes, when eaten, are digested just like other proteins.
CLAIM:
Deficiencies of certain enzymes in certain body types can result in the following health problems: hypoglycemia or diabetes; mood swings; depression; allergies; PMS; acne; fatigue; cold hands/feet; low blood pressure/high blood pressure; neck and shoulder pain; arthritis; muscle spasms; difficulty losing weight . . . high cholesterol/heart disease; toxic buildup/leaky gut syndrome; joint inflammation; sexual dysfunction; osteoporosis; insomnia; weakened immune system; sinus infections.
FACT:
This list is complete nonsense. Most of the conditions have nothing whatsoever to do with any type of enzyme deficiency. A few of the listed conditions may be associated with uncommon metabolic disorders in which lack of an enzyme occurs. No condition on the list can be alleviated by enzyme pills.
