NUTR 1010 Lecture Notes - Vitamin, Nitric Oxide, Avocado

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Published on 14 Apr 2013
School
University of Guelph
Department
Nutrition
Course
NUTR 1010
Professor
Week 8 Antioxidants
October 24th, 2012
What Are Antioxidants?
- Chemicals that prevent oxidation
Oxidation:
- Molecules are a physical unit of an element; they consist of atoms; all atoms are unique; all atoms have a nucleus
(positively charged) and it is surrounded by electrons (negatively charged); the opposite attractions keep them together.
- During metabolism (the process by which our bodies break down and build up molecules), atoms may lose electrons; this
loss is called oxidation because it is usually fueled by oxygen; atoms can also gain electrons during this (called reduction);
the loss and exchange of electrons usually results in an equal exchange (exchange reaction)
- It happens because we use hydrogen and oxygen to generate energy (ATP)
*Results in the formation of free radicals
Free Radicals
Superoxide (02-) Hydroxyl Radicals (OH) Nitric oxide (NO)
- Can be caused from environmental exposure:
o Exposure to toxic substances: tobacco, asbestos, pollution
o Sun exposure
o Radiation exposure
- They are dangerous because they are “luring” paired electrons away from their stable atoms; creating more free radicals.
- They form within the lipid layer of the cell membrane; when the lipid molecules are destroyed, they do not repel water and
they cannot regulate fluids in ad out of the cell
- Can also damage LDL’s, proteins and DNA.
Can cause: cancer, heart disease, diabetes, arthritis, cataracts, kidney disease, Alzheimer’s, Parkinson’s
Antioxidants: chemicals that decrease the adverse effects of free radicals by:
- Donate their electrons without creating more free radicals.
- Have complex enzyme systems that convert free radicals into less harmful substances.
Major Antioxidants
Vitamin E Vitamin C Vitamin A Selenium
Vitamin Review
- minerals that are essential for us to eat (our bodies can’t make them)
- Can be fat or water soluble.
VITAMIN E
AKA alpha-tocopherol
- fat saleable vitamin (non polar); absorb it better when you eat it raw
- absorbed in the intestines with fat in micelles
- transport in the blood via lipoproteins
- your body stores vitamin e in the adipose tissue (body fat)
- an antioxidant
- works in lipid environments; donates free radicals
Some fatty acids are oxidated more easily than others; poly unsaturated fats.
This is why: saturated fat/trans have a longer shelf life; old fish smells bad, frying in oil with high heat can smell bad.
PUFA
The more pufa you eat the more vitamin e you need to eat; lucky foods that contain pufa also contain vitamin E; oils, avocado, nuts,
seeds, soy products.
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Document Summary

Molecules are a physical unit of an element; they consist of atoms; all atoms are unique; all atoms have a nucleus (positively charged) and it is surrounded by electrons (negatively charged); the opposite attractions keep them together. It happens because we use hydrogen and oxygen to generate energy (atp) Can be caused from environmental exposure: exposure to toxic substances: tobacco, asbestos, pollution, radiation exposure. They are dangerous because they are luring paired electrons away from their stable atoms; creating more free radicals. They form within the lipid layer of the cell membrane; when the lipid molecules are destroyed, they do not repel water and they cannot regulate fluids in ad out of the cell. Can cause: cancer, heart disease, diabetes, arthritis, cataracts, kidney disease, alzheimer"s, parkinson"s. Antioxidants: chemicals that decrease the adverse effects of free radicals by: Donate their electrons without creating more free radicals. Have complex enzyme systems that convert free radicals into less harmful substances.

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