How a molecule of digested food from the gut enters the blood stream

[Anandi]

Molecule of digested food e.g. glucose which is broken down from carbon hydrates in the mouth and duoderum pass along the gut by peristalsis until it reach the lum. The surface of the ilum is line with finger like shapes called villus which increases the surface area for absorbing the digested food. The glucose Molecule passes across the thin wall of the villus by diffusion to reach the blood capillaries surrounding the villus.

[Anandi]

Large molecules must be broken down into molecules small enough to permeate living membranes

Insoluble substances must be changed into substances that can be carried in solution around the body
Complex molecules must be converted into molecules simple enough to be used by the cells in assimilation.