Slides in this set

Slide 1

Preview of page 1

Gut…read more

Slide 2

Preview of page 2

Exchange In The Gut
Digestion in the gut results in our food being
broken down into simple, small soluble
molecules which can be absorbed mainly by
diffusion into our blood. The carbohydrates that
we have consumed will have been broken down
into simple sugars such as glucose.…read more

Slide 3

Preview of page 3

Proteins in our food will have been broken
down into amino acids and lipids will be
broken into fatty acids and glycerol. All of
these molecules are vital for many of our life
processes and so must be moved from the
small intestine into the bloodstream.
· Diffusion is the main process involved in the
movement as there tends to be a steep
concentration gradient between the two
systems. When there is a lack of gradient,
active transport will be used.…read more

Slide 4

Preview of page 4

The small intestine is specially adapted to
promote the rapid movement of food
molecules. The inner lining is folded into
many finger-like projections called villi. Their
surfaces can be further folded and these mini-
projections are called the microvilli.
· All of this vastly increases the surface area for
absorption. Scientists estimate that this can
be up to 2000m2 in humans.…read more

Slide 5

Preview of page 5

To maintain a concentration gradient, the
small intestine has an excellent blood supply
which ensures rapid transport to other parts
of the body.
· Amino acids and glucose diffuse into the
bloodstream but fatty acids diffuse into the
lacteals which are branches of the lymphatic
system. The lining of the small intestine is also
extremely thin and this enables efficient
movement of molecules.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »