UNIT 1 – VITAMIN
I. CLOZE TESTS
1.1. Fill each gap with one of the words given in the box.
A. acid, B. amounts, C. called, D. catalysts, E. clotting,
F. decades, G. involved, H. ingested, I. intake, J. stored
What are Vitamins?
Vitamins are nutrients required in very small _________(1) for essential metabolic reactions in the body. Vitamins are biomolecules that act both as _________(2) and substrates in chemical reactions. When acting as a catalyst, vitamins are bound to enzymes and are _________(3) cofactors, for example vitamin K forms part of the proteases _________(4) in blood _________(5) .
Vitamins also act as coenzymes to carry chemical groups between enzymes, for example folic _________(6) carries various forms of carbon groups (methyl, formyl or methylene) in the cell.
Until the 1900s, vitamins were obtained solely through food _________(7). Many food sources contain different ratios of vitamins. Therefore, if the only source of vitamins is food, changes in diet will alter the types and amounts of vitamins _________(8). However, as many vitamins can be _________(9) by the body, short-term deficiencies do not usually cause disease.
Vitamins have been produced as commodity chemicals and made widely-available as inexpensive pills for several _________(10), allowing supplementation of the dietary intake.
biomolecule
phân tử sinh học
protease
enzym tiêu protein
catalyst
chất xúc tác
ratio
tỷ lệ
clotting
sự đông (máu)
substrate
chất nền / chất phản ứng
cofactor
đồng yếu tố
supplementation
bổ sung
1.2. Fill each gap with one of the words given in the box.
A. accepted B. caused C. eating D. feeding E. healing
F. known G. maintaining H...
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