Intermediate 2 Biology
Everyone should complete:
2-Visking Tube Experiment
Most people will complete:
The Check Test for 9.6
The Home Practice for 9.6
Some people might start:
Torrance Intermediate 2 Biology textbook
p 240 ‘Applying Your Knowledge’
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!
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’!!!
‘The passage of small food molecules through the wall of the alimentary canal and into vessels that can transport them within the body’
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
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…….
The small intestine is very 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