Question

Glucose in the lumen of gut is absorbed:

• A. Mainly by active absorption & some by passive absorbtion
• B. Mainly by passive absorption & some by active absorbtion.
• C. Only by active absorption
• D. Only by passive absorption

Answer 1

Answer: (A)

Various mechanisms are involved for the absorption of the nutrients :
A. Simple diffusion: Some amounts of monosaccharides like glucose, some amounts of amino acids and few electrolytes like $C{l}^{-}$ .
B. Facilitated transport: Some amount of glucose and some amino acids.
C. Active transport: Monosaccharides like glucose (most of absorption), most of amino acids and electrolytes like $N{a}^{+}$ . Absorption of water depends upon osmotic gradient. All above nutrients enter the blood stream after being absorbed.
D. Fatty acids and glycerol are water insoluble, so these are not absorbed in blood stream but in lymph vessels (lacteals).