Exam 2 Notes Proteins Part 2 1 Functions of Amino Acids a Synthesis of non essential amino acids b Protein synthesis c Buffer d Neurotransmitter synthesis e Energy 2 Formation of non essential amino acids a Non essential amino acids i We can synthesize them b Essential i Cannot synthesize ii We get them from our diet iii 9 essential and 1 semi essential iv Synthesized by plants and bacteria v PUT TIM HALL 1 Phe Val Thr Ile Met His Arg Leu Lys vi Conditionally essential 1 Cys Tyr 2 Synthesized from essential amino acids a Met Cys b Phe Tyr 3 If a protein requires an essential amino acid and the body doesn t have it the protein synthesis will halt 3 Protein Formation a DNA RNA Proteins b DNA i Blueprint for all cells ii Written in code 1 A T U instead of T in RNA 2 G C 3 Purines pure as gold A G have 2 fused rings 4 Pyrimidines CUT the pie U only in RNA T C one ring 5 Hydrogen bonding iii Genetic code is confined to nucleus 1 Copy is made that leave nucleus transcription copy mRNA iv only 10 DNA is copied for RNA remainder used to regulate transcription 1 2 promoter elements a binding sites for transcription factors b hormone binding sites thyroid glucocorticoid i v exons coding regions introns non coding regions vi vii mRNA is made from exons c RNA i mRNA messenger RNA ii tRNA transfer RNA 1 copy of the blueprint that can leave nucleus reads mRNA and binds to corresponding amino acid 1 2 3 codons 1 amino acids e g 36 nucleotides 36 3 12 amino acids iii rRNA ribosomal RNA 1 protein synthesizing machinery 2 forms ribosome iv DNA RNA 1 Transcription v RNA protein 1 Translation vi Proteins undergo post translational modifications this is not including rearranging amino acids including adding nutrients to become active proteins e g iron in hemoglobin d Primary Sequence e Primary Structure i Amino acids linked by peptide bonds like a necklace ii Determined by DNA i Sequencing of amino acids in polypeptide chain ii Determines final structure 1 R chains affect coiling folding f Secondary Structure i Folding of primary structure mostly hydrogen bonding 1 Alpha helix cylindrical hair muscle 2 Beta pleated sheets silk sheets 3 Alpha helix and beta pleated sheet on same strand g Tertiary Structure i Looping and binding of amino acids located at considerable distance apart on secondary structure Ionic bonds 1 Hydrogen bonds 2 3 Hydrophobic interactions 4 Disulfide bonds Cys Met a Hard to break h Quaternary Structure i 2 or more polypeptide chains 1 E g hemoglobin 4 subunits antibodies i Functional Capacities for Proteins i Enzymes all enzymes are proteins but not all proteins are enzymes ii Hormones from 1 amino acids 1 E g insulin 2 polypeptide chains disulfide bridge made in 1 location and transported in blood stream to location of function iii Structural proteins 1 Contractile proteins muscle actin myosin 2 Fibrous proteins collagen cartilage hair bone iv Cell Membrane Proteins 1 Embedded in membrane 2 Membrane channels transporters a Glucose transporters b Na transporters 3 Receptors a b LDL receptors Insulin receptors v Plasma Proteins 1 Albumin a Synthesized in liver and released in blood b Transports nutrients B6 Zn Ca fatty acids c Maintains oncotic pressure d Fluid is attracted to albumin causing higher pressure within vein i In vein albumin pressure is about 26 e Low levels of albumin in blood fluid retention edema j Mutations i Alterations or changes in the genetic code usually associated with a disease 1 Point mutation error in single DNA base can make no little difference a E g sickle cell b Seen in African Americans to prevent mosquitos the cells can t carry oxygen the same way and they are shaped differently so they re stuck in capillaries survival mechanism 2 Gene arrangements gets swapped 3 Frame shift mutations shift over 4 Gene deletions deleted 5 Duplications ii Mutations can happen spontaneously but usually comes from genes family lines k Some Nutrient Related Mutations Related TopHat Question If our DNA improperly codes for a protein we can consume it to fix the problem FALSE We would just end up digesting the protein Instead we need to change our diet i Cystic Fibrosis 1 Defective gene and its protein product 2 Body produces unusually thick sticky mucus 3 In lungs and pancrease 4 Patients are usually thin ii Wilson s Disease 1 Defective for getting copper outside of body 2 Copper found around eyes iii Acrodermatitis Enteropathica 1 Zinc deficiency doesn t let zinc out of enterocyte 2 Zinc important for skin diaper rash creams skin conditions iv Hemochromatosis Iron overloading 1 2 Treatment donate blood v Vitamin D Resistant Rickets 1 Problem with the protein 2 Genetic mutation in the VDR alter the function of the receptor 3 Vitamin D necessary to absorb calcium maintains Ca2 that goes in and out of bones 4 Signs symptoms soft bones bowed legs rickets children osteomalaygia adults astomelsia 5 Treatment very high vitamin D doses vi Maple Syrup Urine Disease 1 Problem with enzyme 2 Metabolized proteins to become toxic defective build up 3 Urine smells sweet 4 Deficiency of 1 of the 6 proteins that make up the complex BCKD branched chain alpha keto acid dehydrogenase 5 Defective BCKD protein complex breaks down leucine isoleucine valine vii Carbamoyl Phosphate Synthesis 1 Born with this 2 Neonatal hyperammonia viii Phenylketonuria 1 Polymorphisms l Inability to break down phenylalanine and tyrosine i Changes usually not disease related ii Responsible for individual differences 1 Differences in metabolism 2 Differences in response to exercise 4 Functions of Amino Acids a Amino Acid Metabolsim i Affecting one of the groups from the carbon 1 Decarboxylation a Remove carboxyl group 2 Side chain cleavage a Remove side chain 3 Deamination a Remove NH3 group 4 Transaminaton a Move NH3 group ii Decarboxylation 1 Removal of carboxyl group 2 Neurotransmitter synthesis a Affects depression muscle stimulation thought processing etc b Tyrosine dopamine epinephrine norepinephrine c Glutamate GABA gamma amino butyric acid i Via glutamate decarboxylase ii GABA is inhibitory w o it there would be build up d Tryptophan serotonin stimulation seizures iii Side Chain Cleavage i Found in turkey 1 Removal of R chain 2 Not seen a lot 3 Seen in Serine and Glycine a Folate metabolism B9 iv Deamination 1 Amino acid alpha keto acid NH3 ammonia a Ammonia urea cycle liver kidneys b Ammonia urine 2 Take off N group 3 E g glutamate via glutamate dehydrogenase alpha ketoglutarate NH4 v Transamination 4
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