Biochemical Functions of Proteins

Biochemical functions of protein - structural Protein" A-Fibrous proteins water insoluble, resistance to most Collagen Bone teeth tendons... heat or pl ...Cartilage ligament. 2-Elastin & liver lungs. blood vessels. Q 3_a-keratin skin. hair nails «Disulfide bond-S-S- B-Globular Protein water soluble sensitive to heat or PH " 1-Albumin & transport Ca", drugs, bilirubin 2_hemoglobins Oz transport 3-Trans ferrins tron transport. 4-Trans Cobalamines vit. B12 transport 5_Ceruloplasmins Copper transport 6-Enzymsa Catalysis 7. Some hormones& insulin 8-Actin, myosin, antibodies "Igm. IgG" Clotting factors fibrinogen *amino acids 8- *300 amino acids in nature only 20 are humen Proteogenic G all amino acids have the same basic structure. * all Coded by gene DNA" GCAT ONA nucleolus Transcription [CGAUCCGACUAG] «Genetic Code >>> mRNA Ribosome Translation a.al a.a amino acid peptide band a.a Lamino acid "poly peptide chains or protein - properties of amino acid 1- water soluble ionized... L D 2_called a-amino acid 3-melting Point 200C 4_ act as base and acid Amphoteric or ampholytes 5_ Zwitter ion net charge is zero Bipolar Cathode Electric field tev anode *Zwitter ion dosent migrate in electric field * amino acid structures H x-amine HNC00 a-carboxyl + acids "base" R.) distinctive side Chain physiological PH-IEP 7.3-7.4 6-Isoelectric point is the pH that make the aming IEP PI acide in Zwitter form. 7-Chiral Carbone attach 4 different groups. Asymmetrical *_all amino acids contain chirl carbon except glycin -act as neurotransmitter symmetrical HW-C-coo H- not -H 8-optical activity ability of chiral Carbone to rotate plane polarized light to right Dextro rotatory to left levorotatory Led polarized kened light Dextrorotatory polar metter D- amino acid plant led ← E-Jeverotatory levorotatory L-amino acid لا human Enantiomers 14 2 mirror images Compounds + 3HN-С-Соб --Соб CH3 L-Alanine human H OOC-C-NH PECH₃ D-Alanine plants, Qbacterial cell wall,or some antibiotics 9_dll amino acidt have the same basic structure except proline Cyclicaliphatic) amino acids Classification nutritional metabolic Chemical A_nutritionals 1- non essential ara «Dispersible» • produced by human Oells & De novo synthsis >> 2-semiessential aa «Arginine histidine)) • Required during pregnancy, growth of children, recovery from illness» 3_essential aa EAA indispensible) * not produced by human Gells * must be obtained from diet PUTTIM HALL 1-phenylalanine "ring" 2-valine melatonin sleep 3-Tryptophan serotonin happiness. 4-Threonine 5-Isoleucine branches 6_methionine sulfur found init 7 leucine 8-lysine note no rings or branches produced by human Gells animal proteins complete.. high biological value Contain all EAAS -Eq & Casein, poultry, meat, fish and egg albumin. *-plant protein « incomplete» low biological value Deficient in one or more GAA Beans methionine, wheatlysine, (maise Corn Tryptophan *Do Dietary complementing metabolic classifications of amino acids During starvationa 18 hours after meal » The amino acids are Converted to glucose and kotome bodies for energy 1_Glucoger a a amino acid liver 14 a.a Kidney →glucose 2. ketogenic a a amino acid liver Leucine →ketone bodies Acetoacetaite Lysine «Acidic alternative fuel pd sonbay 250cl brain energy» 3-mixed glucogenic and ketogenic amino acid. →glucose gluc «PITT →ketone bodies 1. phenylalanine 2 Isoleucine the 3 Tyrasine Tryptophano) Chemical classification According to polarity of side Choir 1549 1-Neutral wrcharged nonpolar & hydrophobic ring r hydro Carbon polarahydrophilic» 3-8-OH hydroxyl 요 2-C-NH2 amide 1--SH thiol 20.9. 2-acidic polar HN-C-Co Rev 1-Glutamate 2. Aspartate Note * non polar oily" not parficipate in hydrogen bonds or ionic bond. *-polar: form H. bonds or ionic bond Electrostatic bond salt bridge 3-Basic polar Ritve 1-Histidine 2-Arginine 3_lysine Chemical classification According to polarity of side Choir R 1504 1-Neutral wicharged SHN-C-Coo 2010. 2-acidic polar H H HW-C-Co Rev 3-Basic polar H Ritue nonpolar & hydrophobic I-Glutamate 1- Histidine ring 2. Aspartate 2-Arginine 3_lysine hydro Carbon polarahydrophilic» 3--OH hydroxyl 요 2-4-NH2 amide 1--SH thiol Note * non polar oily" not participate in Mydrogen bonds or ionic bond. *-polar: Porm H. bonds or ionic bond Electrostatic bond salt bridge neutral, nonpolar, "oily" 1- Glycine simplest & smallest QNo Chiral, no optical activity 2-L-Alanine «A» Q most glucogenic Glycine and alanine are ambivalelats Q nonpolar & Polar 3-L-phenylalanine F. Highly hydrophobic EAA H AN-C-COO H Hー HN-C-COO CH₃ aromatic ring NH3 -CH-C-H 4- L-Tryptophan u indole ring NH 3 • Bulky hetrocyclic ring W CHC-H Coo a . Indole ring highly hydrophopic» Tryptophan. vit-Bó cofactoris serotonin Carboxyl CO2 De Carboxylase الانزري Tryptophan Vit.B6 cofactos Niacin «Vit. B3 1 mg "60mg" 5. L-methionine « sulfur, EAA NH3 1 «highly hydrophobie CH-S-CH2-CH2-C-H Coo 6-L-proline "Cyclic aliphation only - found issi inside or outside proteins CH CHI NH2 1 - secondry amino acid "Imino acid" CH2-C-H - Contian Imino group Proline Vitchydroxyproline a modifid avan H • collagen Collagen strength B. Amide Containing a.a& 1. L-Glutamine «Gln" NH3 2HN-C-CH-CH-C-H amide group Coo NH 2-L-Asparagine «Asn» N HN-C-CH-C-H amide group both are nonessential C-sulfhydryl «Thiola.a8- L-Cysteine "Cys" NH Thiol HS-CH-C-H "Reduction" 1 Coo Formation of L. Cystine «modification a.a Disulfid bond cys-Scovalent S-Cys Disulfid bond is found in insulin, a-keratin, Immunoglobulins BME & B-mercapto ethanol, hydrolyze disulfide bond Location of a.as in protein Exterior P-Ho 600 Interior sugar Ho basica a Ionic acidicava bond sugar.....NH- aia "Glycoprotein» "Globular protein, " in aqueous solution The essintial amino acids can produce nonessential ara in human body? Phenylalanine essential 애 human →Tyrosine nonessential methionine essential human Cysteine nonessential «sulfur Acidic amino acids Negatively charge at physiological PH NH + 1-L-Glutamate «E» -C-CH-CH-C-H ४-carbx yl Coo Glutamate de carboxylase-aminobutyric acid Vit.B6«coenzyme inhibitory neurotransmittery relaxation sher U GALA 2-L-Aspartate «D» NH -CH-C-H + carboxyl Aspartate Coz →B-alanine decarboxylase HN-CH-CH-COO • Derived amino acid, Pound in vitamin Bs pantothenic acid. Basic amino acids "positively charged at physiological pH, 1- L-lysine «k» PAC Epsilon amine Co 2- L-Arginine «R» 1 Guanido HN--CH2-CH-CH-C-H 3_L-histidine («H». imp Imidazole ring Imidazole H₂-- found in hemoglobin & myoglobin +HN- - NH store Oz inmuscleb weak basic abuffer" * Amphotric properties of a.a -Amino acid can act as acids or bases At acidic ph, amino accept proton and act as I basel t地。 -At basic Ph, a a donate Proton and acts aslacid/-ve -At IEP, iso electric "point" the a a is IZwitter ionl IEP-Pki+Pk2 = 2.3+98 = 5.7 2 2 * new amino acids • 21 seleno Cysteine «Contain the antioxidant selenium >> • Produced from serine • Pound in enzymes like. "glycine reductase, selenoproteins. selenium protect RBC membrane from a oxidation. H2O2 REC selenium hemolysis!! •22 pyrrolysine «cyclic • produce from stop codon UAG methionine serine stop AUG UCA UAG Codon MRNA Codon *Derived nonstandard amino acids 1-4-Hydroxy proline, 5 hydroxy lysine are found. in Collagen OH-pro 189-6th olf collagen strength 2-L-Cystine «Cys-S-S-Cys "x-keratin 3-ornithine, Citrulline are found in Urea cycle -B-alanine is found in Vit. B5Q pantothenic acid CO2 5-Cysteine →Taurine & Bile salts" "Por lipid absorption" 6-Desmosine [lysys] is Pond in elastin 7 Glutamate vit.k lutamat →X-Carboxy glutamate Carboxyl <