Absorption Process

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Slide 1

Absorption Process

Intermediate 2 Biology

Slide 2

Learning Intentions

15th Jan

Everyone should complete:

1-Absorption Model

2-Visking Tube Experiment

3-Small Intestine

Most people will complete:

The Check Test for 9.6

The Home Practice for 9.6

Some people might start:

Problem solving

Torrance Intermediate 2 Biology textbook

p 240 ‘Applying Your Knowledge’

Slide 3

Absorption

The alimentary canal (or gut) is a long tube inside the body

Any food in the alimentary canal is still outside the cells of the body

To get inside the molecules of the food have to be able to pass through the wall of the alimentary canal

Now try the ‘Model Absorption’ kit!

Slide 4

Think…

What does the piece of tube in the model represent?

Why can the food molecules inside the tube still be regarded as ‘outside’ the body?

Which food molecules in the model were able to pass through the wall of the tube most easily? Why was this?

Why were the protein molecules in the model unable to pass through the wall of the tube?

Now complete the ‘Notes’!!!

Slide 5

Absorption

‘The passage of small food molecules through the wall of the alimentary canal and into vessels that can transport them within the body’

Slide 6

Visking Tubing Experiment

a diagram of the experiment when set up

what the visking tubing was being used to represent

how you tested for starch and glucose and a table of your results

an explanation of the results in terms of size of the food molecules involved

Slide 7

Small Intestine

Small, soluble food molecules are absorbed through the wall of the small intestine

To absorb food molecules efficiently the small intestine has three main adaptations…….

Slide 8

A Large Surface Area

The small intestine is very long

-6m long

The inner surface on the intestine is folded

-covered with many finger-like projections called villi

-greatly increase the surface area in contact with digested food

Slide 9

Slide 10

Villi