Answer to Question 1
d
Answer to Question 2
Antioxidant vitamins include vitamin C, vitamin E, and beta-carotene. Antioxidants are compounds that protect other compounds (such as lipids in cell membranes) from attack by oxygen. Oxygen triggers the formation of compounds known as free radicals that can start chain reactions in cell membranes. Vitamin E and beta-carotene protect fat-soluble substances from oxidizing agents; vitamin C protects water-soluble substances the same way. By being oxidized itself, vitamin C regenerates already-oxidized substances such as iron and copper to their original, active form. In the intestines, it protects iron from oxidation and so enhances iron absorption. In the cells and body fluids, it helps to protect other molecules, including the fat-soluble compounds vitamin A, vitamin E, and the polyunsaturated fatty acids.
Like beta-carotene, vitamin E is a fat-soluble antioxidant. It protects other substances from oxidation by being oxidized itself. If there is plenty of vitamin E in the membranes of cells exposed to an oxidant, chances are this vitamin will take the brunt of any oxidative attack, protecting the lipids and other vulnerable components of the membranes. Vitamin E is especially effective in preventing the oxidation of the polyunsaturated fatty acids (PUFA), but it protects all other lipids (for example, vitamin A) as well.
Events of the postabsorptive state.
A plot of trophic diversity across the major groups of organisms shows highest trophic diversity amo
Pacific Silver Fir cone debris from feeding Douglas Squirrels, North Cascades National Park
Cast of Isotelus rex, the largest known trilobite from the middle to upper Ordovician of North Ameri
Acceptable ranges of respiratory rate
The Sleep/Waking Flip-Flop According to Saper et al. (2001), the major sleep-promoting region (the v