Flashcards in Protein Deck (12):
What is a protein?
Amino acids joined by peptide bonds
how many amino acids are there?
what is an essential amino acid?
One that must be eaten preformed in the diet
Name the essential amino acids
Give some examples of functional roles and products that amino acids are used for
Energy transduction - ATP
What are the inflows and outflows of the amino acid pool?
Inflow - dietro intake, de novo synthesis and protein degradation
Outflow - protein synthesis, oxidation, other metabolic pathways
How much protein do we need and how did the WHO come up with this number (in 1973)
They calculated the loss of nitrogen in an energy balanced, protein free diet. Nitrogen was lost in urine, skin, faeces and misc. This added up to 0.34g.kg protein per day, this was the average so they added on 2 standard deviations.
This has the limitation that it assumes 100% efficiency in metabolising dietary proteins
What process might result in protein deficient states?
Increased demand e.g. infection or stress
Increase in losses e.g. burns, diarrhoea, haemorrhage
Failure of conservation systems e.g. impairment or urea salvage within the colon
What is the R-group?
The side chain to amino acids, which is the group that varies between amino acids
What are the groupings of amino acids based on the nature of their R groups?
1. Glycine - has a H atom as its side chain
2. Those with aliphatic (hydrocarbon) side chains
3. Those with hydroxyl aliphatic side chains - i.e containing an OH side chain
4, Those with aromatic side chains
5. Basic side chains
6. Carboxyl groups in the side chains
7. Those with sulphur containing side chains
8. Those with amide groups in their side chains
What is the general structure of a protein?
May be comprised of hundreds of amino acids linked together
Each protein will have a free amino group at one end (the N-terminal) and a free carboxyl group at the opposite end (the C-terminal)