The two browsers that seem to be the fastest ways of accessing the video clips are Safari on a Mac and Internet Explorer on a Windows-based computer. 

Video Clip: Environmental problems
of raising lots of protein-rich foods

approximately 6 minutes
If the movie isn't showing up on your computer, you may not have the latest version of QuickTime on your computer.  Click here to download the newest version of Quick Time.


(The above Video Clip says there is not a supplier of pasture-raised chickens.  That has changed, which you'll find out about in Lecture 7B next week.)
h.    So what's a person to eat if vegan (no animal food) is not your choice? 

This is a tough question.  The only thing I can think of is to perhaps limit protein-rich food and to select sustainably raised choices when possible.  Perhaps if money is saved by limiting protein-rich food, it   could go toward the higher cost of sustainably raised choices. 
       

B.  Protein Deficiency: Global Hunger (discussed at the start of this lecture)

VI  Digestion of Protein
The two browsers that seem to be the fastest ways of accessing the video clips are Safari on a Mac and Internet Explorer on a Windows-based computer. 

Video Clip: Digestion of Protein- Part 1
approximately 10 minutes
This Video Clip will refer to "Foods & Digestion" on page 66 of your packet.

If the movie isn't showing up on your computer, you may not have the latest version of QuickTime on your computer.  Click here to download the newest version of Quick Time.

Video Clip: Digestion of Protein- Part 2
approximately 8 minutes
You should now be able to complete page 66 in your packet "Foods and Digestion".  If you still have questions about that page, please post them in our FORUM.


VII    Using Amino Acids

Once the digestive system has enzymatically digested a protein in food so that it has been broken down to amino acids,  the amino acids are absorbed into the villi (then the blood), as shown in a previous Video Clip.  

The amino acids then travel in the  blood to cells all over the body.

The next section describes what happens when an amino acid from a protein in food gets to a cell.

A.    If there's NOT enough glucose available to the cell, the amino acid will be stripped of its nitrogen, which is excreted in urine.  The image below is again the amino acid, aspartic acid.

Aspartic Acid
It is the liver that strips the nitrogen off and the kidney which puts it in urine for excretion.(That's why a baby's diaper smells like ammonia, which is NH3.)

Once the NH2 has been stripped off, the rest of it will be rearranged into glucose for use by brain, if needed.  

Glucose    

If actual glucose isn't needed, it will be burned as fuel.

B.    If there IS enough glucose available to the cell, the amino will be used to
  • make a protein the cell needs, like tissue proteins, muscles or enzymes or it will be used   
  • make another amino acid the cell needs     
  • make other small nitrogen-containing compounds such as niacin
If none of those are needed, it would be rearranged and stored as fat.

C.    If Carla has been following a high protein and low carbohydrate diet,
what would be happening is part A.  (above).  In other words, the amino groups in the amino acids of much of the protein she's eating would be split off and the remainder of the amino acid would be changed to glucose for the brain.  

            
D.    If Don has been eating a diet with plenty of foods with carbohydrate & protein,
what would be happening is part B.  (above)  In other words, the protein would be used to supply amino acids to build.    If he is consuming more calories than he needs, the protein would be changed to fat.   

E.    The body can use either liver glycogen or muscle protein to make glucose for the brain.  The body cannot change body fat into glucose for the brain, at least not in enough of an amount to matter.

END OF LECTURE 6A.
Now you're ready for 6B.