Amino acids - Pharm

• genetic material

DNA

• from nucleic acids

• template for protein synthesis

RNA

• from amino acids

• molecules of the cell that perform work, multitude of functions

Proteins

• carbohydrates

• short term energy storage using glucose

Polysaccharides

• membrane components

• long term energy storage - triacglycerol

Lipids

• building block of proteins

• synthesis of hormones and neurotransmitters - thyroxine, serotonin, adrenalin

• source of energy

• transport/removal ammonia

• glutamate/glutamine - movement of H+

• synthesis of other biomolecules

function of amino acids

• position of the common carbon and other atoms in the side chain of an amino acid indicated by numbers or G reek letters

• isomers derived from alpha carbon - L form usually

structure of amino acids

• Leucine

• Isoleucine

• Valine

branch chain amino acids

• OH converted to Amide

• Asparatate

• Apasagine

• Glutamate

• Glutamine

amino acid with acidic groups

• histidine

• tryosine

• phenatylaine,

• tryphotphan

amino acid with aromatic rings

• histidine

• lysine

• arginine

Amino acids with basic side groups

• Proline

Imino acid

• Cysteine

• Methionine

Amino acids with sulphur

• Threonine

• Serine

• Tyrosine

Amino acids with hydroxyl groups

• Val - Valine

• Leucine - Leu

• Isoleucine - Ile

• Threonine - Thr

• Methionine - Met

• Lysine - Lys

• Phenylalanine - Phe

• Tryptophan - Trp

Essential amino acids

• Arginine - Arg

• Histidine - His

Semi - essential amino acids

• Arginine

• Asparagine

• Aspartate

• Cysteine

• Glutamate

• Glutamine

• Glycine

• Histidine

• Lysine

• Serine

• Threonine

Hydrophilic aa

• Alanine

• Isoleucine

• leucine

• Methionine

• Proline

• Phenylalanine

• Tryptophan

• Tyrosine

• Valine

Hydrophobic aa

• amino acid links with peptide bonds

• cant rotate

• strong covalent bond

• less than 50 aa - peptide

• more than 50 aa - protein

Peptide bond

• alpha helix

• beta pleated sheets

Secondary structure

• irregular geometry

• Point where the polypeptide turns and changes direction

• Hairpin turns where the chain abruptly changes direction

• Connects anti-parallel and parallel strands of a β- sheet

• Contain more Proline and glycine

• alpha helix and beta srands - make it flexiable

• inner protein surface

Beta turns

• forms a native form

• in the blood or membrane of the cell

• interacts with water in body

• domains - repeated patterns in the structure

Teritary structure

• covalent bonds between cystein residues - provide rigidity to teritary structure of proteinsn

• may have inter or inter molecular disulfide bonds

Disulfide bons and teritary structures

• stabilised by disulfide bonds (These are small molecules secreted by white cells to attract more white cells to areas of infection or Injury

chemokines

• association between two or more protein chains (subunits) into a large stable structure

• bind by non-covalent bonds

• same subunits - homopolypeptides

• different subunits - heteropolypeptides

• haemoglobin - 4 subunits

• insulin 6 units - 1 monomoer is active

• Ferritin - 24 subuits - contain iron

quaternary structure

• Some small organic and inorganic ions can be tightly associated with proteins and be essential to function

• Copper (Cu), Iron (Fe) or Zinc (Zn)

• Haem – within haemoglobin or myoglobin

Prosthetic group

• proteins can denature

• protein chaperone - fold the protein for use inside cells helps protein ensure it does its function

• many proteins not stable at body temp or pH

Protein stability

• “tagged” & destroyed

• can accumulate, and as individuals get older, this occurs more frequently

misfolded proteins

• a rare disease that occurs when a protein called amyloid builds up in organs

amyloidoses

• change in haemoglobin

• Single Glutamate becomes a Valine in the b-chain

• Allows the deoxygenated form of haemoglobin to stick to itself forming chains, or a fibre of subunits on top of each other

Sickle cell

• can have single amino acid changes

• Stretchy skin of Ehlers-Danlos syndrome (there are many types) ◦ hyper joint mobility

collagen

• soluble

globular proteins

• insoluble

fibrous proteins

• Support - Structural proteins create a 3D framework

• Movement - Proteins for muscle contraction and cell movement ◦ Transport - Insoluble lipids, respiratory gases, metals & hormones need transport proteins to carry them around

• Storage - containing iron (ferritin) or source of amino acids (Casein)

• Buffering - Prevent pH changes within cells and tissues

• Metabolic regulation - Enzymes accelerate chemical reactions

• Coordination (communication) and control – Hormones and growth factors

• Defence - waterproof proteins of skin & antibodies, clotting proteins

• Chaperone – assist correct folding of other protein

protein function

• L aa and L aa carrier transport

• Final digestion - intestinal lumen, bursh border, cytoplasm

• Na dependent and independent carriers of aa

• separate di/tri peptide carrier system on mucosal cells

• infants - can absorbed antibodies

protein absorbed