未被消化的蛋白质.ppt

未被消化的蛋白质
A. The physiological &
nutritious function of
proteins
nitrogen balance &
protein requirement
1. nitrogen balance
a. concept
b. experiment
c. 3 conditions
nitrogen equilibrium
negative nitrogen balance
positive nitrogen balance
2. minimal requirements of
protein
3.essential amino acids and
their biological value
an indicator to valuate the
nutritional value of the proteins
biological value
4. Complementary function
of proteins
B. Digestion ,absorption,&
putrefaction of proteins
未被消化的蛋白质,未被吸收的氨基酸，肽
large intestine
bacterias
Decarboxylation
deamination
有毒； amine ,H2S indole
hydroxybenzene、ammonia（NH3)、
other：CO2,CH4
Nutriment
Fatty acid、vit
Absorption in intestine
excrete
blood
liver
• decarboxylation
• reductive & deamination