BC1502 Introduction to Cell and Molecular Biology

Macromolecules

Nutrition & biochemistryLecture 5b

James A Martiney, Ph.D.

Enzymatic Digestion of Nutrients

Figure 47-9 p1053

Absorption and digestion of disaccharides and small peptides

Figure 47-14 p1057

Polysaccharides and disaccharides

DisaccharidasesBrush-border cells of

intestinal mucosa Amino acidsMonosaccharides

To extracellular fluid and blood

Small peptides

Lumenof small

intestine

Aminopeptidases

Figure 47-15 p1058

Brush-border cells of

intestinal mucosa

Lumenof small

intestine

Interstitialfluid

Endoplasmicreticulum Monoglycerides

Triglycerides

Chylomicrons

Chylomicrons exit the cell byexocytosis and enter lymph vessels.

Chylomicron

Fatty acids

Micelles

Bile salts

Monoglycerides Fatty acids

Absorption of fat-soluble products of digestionby intestinal mucosa cells

Lipoproteincoat

Aggregatedtriglycerides Aggregate and coated

with lipoprotein