Amino Acids Amino Acids Essential amino acids, also called indispensable amino acids, must be supplied by the foods people consume.
Essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenyalanine, threonine, tryptophan, and valine.Nonessential amino acids, also called dispensable amino acids, are ones the body can create.
Quaternary structure two or more polypeptides The Coiling and Folding of a Protein Molecule Protein shape and function
Proteins Protein Functions Some carry and store materials- hemoglobin Some provide strength- muscle fibers Some require minerals for activation (example: hemoglobin and the mineral iron).
Protein denaturation is the disruption of the stability of the protein The protein uncoils, it loses its shape, and loses its ability to function.Proteins can be denatured by heat and acid (stomach acid) After a certain point, denaturation cannot be reversed- cooked egg Proteins- Review Amino Acid Chains
Dipeptide polypeptide Amino acid sequences
Specific for each protein Protein shapes Polypeptide chains twist depending on their amino acid sequence Protein functions-unique shape allows them to perform their function Protein denaturization-heat, acid disturb their stability and cause them to denature; they uncoil and lose their shape and function Protein Digestion in the GI Tract
Protein Digestion Protein Synthesis Human body contains an estimated 30,000 different kinds of proteins.
Each protein is determined based on their amino acid sequence which is determined by genes.The instructions for making every protein in the body are transmitted by the DNA in the nucleus of every cell Protein Synthesis Delivering the Instructions Protein Synthesis Lining Up the Amino Acids Protein Synthesis Sequence Errors Protein Syntheses Nutrients and Gene Expression -
Cells regulate gene expression to make the type of protein needed for that cell, in the amounts and rates it needs them Nearly all body cells have the genes to make all proteins Each cell makes only the protein it needs
Proteins in the Body Roles of Proteins Building Materials for Growth and Maintenance Building blocks for most body structures, id, collagen Replaces tissues including the skin, hair, nails, and GI tract lining, muscles, organs Hormones
Messenger molecules and some hormones are proteins Regulate body processes.An example is insulin.Enzymes
Proteins that facilitate the building of substance Proteins that break down substances
Roles of Proteins Enzymes
Roles of Proteins
Regulators of Fluid Balance In critical illness or malnutrition, proteins leak out of the blood vessel and into the tissues Fluid accumulates and causes swelling, or edema Proteins in the Body Roles of Proteins Acid-Base Regulators Proteins have a negative charge; they attract positive
hydrogen ions By accepting and releasing hydrogen, they control acid-base balance Proteins in the Body Roles of Proteins Transporters
Carry lipids, vitamins, minerals and oxygen in the body Act as pumps in cell membranes, transferring compounds from one side of the cell membrane to the other Transport Proteins Roles of against disease Fight bacteria and viruses, that invade the body Provide immunity to fight an antigen more quickly the second time exposure occurs
Proteins in the Body Roles of Proteins Source of energy and glucose if needed Will be sacrificed in times of starvation
Other Roles Blood of Proteins Hormones Antibodies Fluid Acid-base
balance Proteins regulate body processes.
(Some hormones are made of protein.) Proteins inactivate foreign invaders and protect the body against diseases
.Proteins help maintain the volume and composition of body fluids Proteins help maintain the acid-base balance of body fluids by acting as buffers.Roles of Proteins Transportation Energy
Proteins transport substances such as lipids, vitamins, minerals and oxygen, around the body s energy needs.Protein Metabolism Protein Turnover:
Proteins are continually made and broken down.amino acid pooland blood Remade into new protein.Constant process Protein Metabolism Nitrogen Balance: Intake from food (amino acids) balances with nitrogen excretion in feces, urine and sweat Nitrogen in = Nitrogen out.
nitrogen out =Positive nitrogen balance Growing infants, children, pregnant women They are retaining protein in new tissue as they add blood, bone, muscle Nitrogen out Nitrogen in= Negative nitrogen balance Starvation, burns, infections, fever Protein Metabolism
Using Amino Acids to Make Proteins or Nonessential Amino Acids
Cells can assemble amino acids into the protein needed Can use essential amino acids to
make non-essential amino acids Using Amino Acids to Make Other are made from the amino acid tyrosine.Tyrosine can be made into the melanin pigment or thyroxin.
Tryptophan makes niacin and serotonin.
Protein Metabolism Using Amino Ac
But thats not the case.All of the amino acids are important in one way or another and ignoring can be a big mistake.
Lets take alanine for example.Most feel that alanine, a non-essential amino acid, has no place in an amino acid formulation.
But theyre wrong.
2 the liver first to be converted to glucose whic3,4ne is deaminated, and decarboxylated to form ubstrate for gluconeogenesis pyruvate is carboxylated by pyruvate carboxylase to oxAlanine the Essential, Non-Essential Amino Acid Dr.Mauro Di Pasquale MD glutamine and alanine.5that stimulation of K+ inflow plays a major role in the mechanism of alanine-induced 6
e levels in many foods including beef, lamb, milk products, is no appreciable alanine in many foods including chicken, fish, eggs and bacon.
Even non-competing bodybuilders may run into order to decrease saturated fat intake.This usually means decreased consumption of
quality protein and/or alanine supplementation a necessity.
essential is to cannibalize cellular structur catabolize body proteins in an effort to sthe use of exogenous alanine exercise induced proteolysis and increase the avai e has effects on both insulin and glucagon 7glucose recovery from hypoglycemia.8 As well it has been shown that alanine decreases proteolysis9secondary to the provision of an energy source10 or an increase in cellular hydration (see below).The uptake of alanine increases the intracellular content11
The use of exogenous alanine would decrease the need for catabolism of muscle, and intracellular pool of free amino acids by decreasing the use of other amino acids for
2007 Dr.Mauro Di Pasquale the Essential, Non-Essential Amino Acid Dr.
Mauro Di Pasquale MD ine would provide extra energy for anaerobic intracellular glucose availability.
A diet low in alanine should be supplemente source of alanine and other amino acids.These supplements are not merely useful convenient alternative food choices, but
Because of its anabolic and anticatabolic effects, a case could be made for alanine supplementation for all athletes wishing to regardless of dietary alanine intake.
As such, alanine is included in
excessive exercise and
Mauro Di Pasquale the Essential, Non-Essential Amino Acid Dr.Mauro Di Pasquale MD 1lism in exercising man.J Clin Invest.2 Korach-Andre M, Burelle Y, Peronnet F, Ma[15N]alanine ingested during prolonged exerci3AA.Post-exercise ketosis in post-prandial exercise: effect of glucose and alanine inges4 Koeslag, JH, Noakes TD, Sloan AW.
The effects of alanine, glucose and starch ingestion on the ketosis produced by exercise and by starvation.J Physiol 1982;325:363-376.5 Parry-Billings M, Bevan SJ, Opara E, Newsholme EA.
Effects of changes in cell volume Biochemical Journal 1991;276(Pt 2):559-61.
6 Rivas T, Urcelay E, Gonzalez-Manchon C, Parrilla R, Ayuso MS.Role of amino acid-induced changes in ion fluxes in the regulat7 Wiethop BV, Cryer PE.Glycemic actions of Care 1993;16(8):1124-30.
8 Wiethop BV, Cryer PE.Alanine and terbutali9 Venerando R, Miotto G, Kadowaki M, Siliprandi10 Seglen PO, Solheim AE.Effects of aminooxyacetate, alanine and other amino acids on protein synthesis in isolated rat hepatocytes.Biochimica et Biophysica Acta 11 Rivas T, Urcelay E, Gonzalez-Manchon C, Parrilla R, Ayuso MS.
Role of amino acid-induced changes in ion fluxes in the regulat J Cell Physiol 1995;163(2):277-84.