08 Proteins & Amino Acids Flashcards
What elements are amino acids made up of?
Carbon
Hydrogen
Oxygen
Nitrogen
What 3 sections to amino acids contain and how many known amino acids are there in nature?
Amine group at one end - NH2
Carboxylic group at other end - COOH
Unique side group which is different in each amino acid - denoted by R.
Approx 1,000 in nature.
How many amino acids are used in the synthesis of protein and how many of those are essential.
What are non-essential and conditionally essential AA’s?
20 build protein.
9 ar essential as the body cannot make them and needs to be obtained from diet.
Non-essential can be made by the body, conditionally essential need certain conditions and elements like vits, mins etc.
What are the 9 essential AA’s?
Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine
What are some conditionally AA’s?
Arginine Carntine Cysteine Glutamine Glycine Ornithine Proline Serine Taurine Tyrosine
What can denature a protein?
Heat, acids/alkalis, high speed mechanical mixing that disturb their structure and unravels the structure.
What are the 8 functions of proteins?
As Building materials - muscle, skin, blood, bone
As Enzymes - break/build/transform substances
As Hormones - made from cholesterol, AA’s & polypeptides
As Immunoproteins - Immunoglobulins & antibodies.
As Transport proteins
As acid base regulators
As fluid balance regulators
As conjugated proteins - joined to non-protein components.
Name some examples of proteins/AA’s that are made into hormones.
Tyrosine + Iodine = Thyroid Hormones
Tyrosine used to make dopamine, adrenaline
Tryptophan used to make melatonin
Name some immunoglobulins and where are they found and how are they used?
IgG, IgM, IgA, IgE, IgD.
Found in blood and bodily fluids.
Used to identify foreign objects.
Name some transport proteins and what do they carry?
Albumin - Ca, Zn, B6
Haemproteins - O2
Transferrin - Fe
Transthyretin+Retinol - Vit A
How do proteins work as acid base regulators?
Proteins have neg charge on surface which attract Hydrogen (+) atoms.
By accepting and release H atoms, they can maintain acid/base balance in body fluids.
How are proteins fluid regulators?
If proteins leak from capillary walls fast than they can be re-absorbed this causes swelling, oedema.
Give an example of a conjugated protein?
Glycoproteins - bound to carbs like glucose, galactose, fructose etc
What’s the difference between exogenous and endogenous proteins and what do they both need in addition for synthesis?
Exogenous - from outside dietary sources (foods)
Endogenous - from internal sources - breaking down of of body cells into amino acids for re-use.
Need nitrogen for synthesis.
What is transamination (and what B vitamin is needed in this) and deamination (and what substance results which is then converted into what)?
Transamination - Transferring/making of a non-essential amino acid into another. B6 needed.
Deamination - stripping down of proteins and nitrogen for re-use. Results in ammonia, then converted in urea by the kidneys and passed out through urine.
Explain how average protein requirements are calculated from nitrogen balance, and from this, what is the estimated average intake calculated to be?
Nitrogen needs to be balanced in the body. Measuring the amount of protein intake with nitrogen in the urine, faeces and sweat, gives an indication of the body’s balance of nitrogen.
Calculated at average of 0.83g per Kg of body weight and 1g for vegans.
What two things influence protein quality?
Amino acid content - making proteins requires all the amino acids necessary to build it.
Source of the protein.
What is recommended for vegetarians and vegans with regard to protein?
Few veg/vegan sources do not contain complete range or protein, so it’s recommended to combine two sources of protein at the same meal to complete the set of required - i.e.. rice and legumes.
What are some of the effects on health of excess protein (5)?
Heart disease - protein from animal sources usually contain high saturated fat and raises cholesterol.
Cancer - animal protein has been shown to have an effect on certain cancers.
Osteoporosis - calcium excretion is high when protein intake is high.
Weight gain - animal protein foods are often high in fat and thus higher calories, although protein is satiating, so can be useful in short term high protein diets.
Kidney disease - high protein increases kidney work (deamination-ammonia-urea)
What are some of the effects on health of inadequate protein and what groups of people can suffer depletion?
Growth retardation in children.
Low energy.
Teens - junk food
Elderly - malabsorption, lack of appetite
Anorexia nervosa
Homeless
What is the most abundant amino acid in the body, is it essential, cond-ess or non-ess, and what are it’s roles?
What neurotransmitter in the brain is it involved in?
Glutamine. Conditionally essential.
Fuels enterocytes, lymphocytes & microphages.
Combines with alanine to transport N in the blood.
Regulates acid/base balance.
Precursor of nucleic acids, amino sugars and glutamate.
Glutamine-glutamate-GABA.
High levels of what, depletes glutamine stores and the generation of what immune cells are reliant on glutamine.
High levels of cortisol depletes glutamine stores.
Ability of lymphocytes to proliferate and generate killer cells is reliant on glutamine.
What vegetable is high in glutamine and it’s juice is useful in what clinical application?
Cabbage and its juice has been shown useful in treating peptic ulcers.
How can glutamine assist those the HIV?
HIV meds and damage intestine walls and lead to mal-absorption. Glutamine can correct this and improve intestinal permeability and absorption using approx 8g per day.
