Proteins

• tons of substances in the body are made up of these and consists of 17% of your body weight and are crucial in body function

• hormones, enzymes, fluid balance,

• valued at 4kcal/G as an energy source

• Albumin is most osmotically active protein in serum – this is why osmotic activity decreases when there are liver problems

• We can create them too

20 AA

• Carbon bound to an amino group.

• 11 are non-essential (dispensable – body can make them)

• 9 essential amino acids (indispensable – must get them from the diet)

• Semiessential (conditionally dispensable) tyrosine and cystine. These are made from essential amino acid counterparts unless they are consumed.

• Essential and non-essential amino acids are present in foods

Transamination

• Metabolic process of synthesizing non-essential Amino Acids (co-enzyme vit B-6 needed)

Deamination

• removal of the amino group from the amino acid

• Amino group is converted to ammonia (by liver) and then to urea (by the liver and the kidney). Urea is excreted by the kidney.

• Bacteria in the environment  urease is the enzyme that breaks down urea to ammonia

• BUN  Blood urea nitrogen, this is a test to see if the kidneys are functioning correctly. If your BUN is high then you are having problems with your kidneys. Not eating protein will lower the BUN, however you will not have everything you need from proteins

The only portal of exit for creatine is the kidneys

Category: Biochemistry Notes