When you take in food those bonds that connect those

When you take in food, those bonds that connect those individual amino acids are
broken apart and the individual amino acids as raw materials are distributed in the
body (hydrolysis in the body)
- They will reform to a different protein or some other kind of protein like enzymes
- The bonds that hold the carbon-oxygen double bond to the nitrogen are called amide
bonds or peptide bonds (peptide bond is a short protein strand)
- Proteins are burned at the rate of 4 calories per gram
- Protein helps with growth, tissue maintenance and enzymatic processes
- When you denature a protein you are disrupting the structure of the protein
Protein Folding
- The amino acids are what make the protein fold together
- Protein folds differently, every fold represents a different capacity to do something in
the body
o Protein folding is at the stage where it is now possible to predict the shape that
a protein is likely to have and therefore to enable scientists to get at what their
function might be
Tryptophan
- The tryptophan amino acid is one of the more complex amino acid
- People use tryptophan to medicate themselves
- Tryptophan is the precursor for serotonin which is an important neurotransmitter
o Serotonin is the molecule that is produced when one eats a considerable amount
of a protein material
o One feature of serotonin is that it induces sleep
- In 1991 tryptophan was banned (in the US) because:
o A contaminated sample linked to eosinophilia myalgia syndrome
 People died
o It increases serotonin levels

o They loosened the restrictions when they discovered that the preparations were
improved to the point where to there was little to no chance of getting this
impurity leading to death
o So you can buy it now as well as pretty much any other amino acid in a health
food store but is it necessary?
Protein Formation
- During protein formation amino acids link together and water is released (the OH
atoms link together – you need two H and one O)
Essential amino acids
- Methionine (semi-essential; required in children)
- Arginine (semi-essential; required in children)
- Tryptophan
- Threonine
- Valine
- Isoleucine
- Leucine
- Proline
- Histidine
- Lysine
- We need to take the right proportions of these in order to make the appropriate body
protein
- Not all food have these amino acids in them – some but now always in the right
proportion
- Amino acids cannot be synthesised by the body in sufficient amounts
Complete and incomplete proteins
- Meat, Fish, Eggs Milk, Soy [tofu is a soy based product]
o These four foods tend to have in almost every instance the balance of the amino
acids that we require

- Wheat, Corn, Rice
o Some amino acids are not present in sufficient proportions
o They are deficient in some of the amino acids – especially in lysine, vegetarians
need to have lysine rich foods to make up the lysine lost from not having meat
- Soy
o 220 m tons world-wide
o 15 million eaten
o 144 million fed to animals
o 54 kg soy protein would only produce about 3 kg of beef resulting from feeding
that soy to cattle