3. What is Zwitter ion?
What is Amphoteric molecule?
What is Isoelectric pH?
4.
5. Peptide bondsPeptide bonds
Different types of amino acidsDifferent types of amino acids
undergo polymerization byundergo polymerization by
peptide bond formationpeptide bond formation
Peptide bonds are importantPeptide bonds are important
part of protein structure.part of protein structure.
If they are broken orIf they are broken or
hydrolyzed it degradehydrolyzed it degrade
proteinprotein
Amino acids
Dipeptide
Tripeptides
Peptides
Polypeptides
(Proteins)
7. PeptidesPeptides
Composed of small number of amino acidsComposed of small number of amino acids
Linkage is peptide bondsLinkage is peptide bonds
Synthesized in bodySynthesized in body
Have specific functionHave specific function
Digestion of protein also leadsDigestion of protein also leads
10. Biologically IMP peptidesBiologically IMP peptides
TripeptideTripeptide : Glutamic acid, Cysteine and Glycine: Glutamic acid, Cysteine and Glycine
Reduced form asReduced form as GSHGSH
Oxidised form asOxidised form as GS-SGGS-SG
Characterised by Gama peptide bonds,Characterised by Gama peptide bonds,
not digestednot digested by peptidaseby peptidase
Found in all cell except nerve cellFound in all cell except nerve cell
Biological antioxidant, Amino acid absorptionBiological antioxidant, Amino acid absorption
GlutathioneGlutathione
11. Biologically IMP peptidesBiologically IMP peptides
FunctionsFunctions::
1.1. CoenzymeCoenzyme in oxidation reduction reactionin oxidation reduction reaction
2. Maintains Red Cell2. Maintains Red Cell Membrane integrityMembrane integrity
3.3. Protects HBProtects HB against Oxidationagainst Oxidation
4. Free radical and peroxide4. Free radical and peroxide scavangingscavanging
5.5. DetoxicationDetoxication
GlutathioneGlutathione
Hemolytic anemia due to G6PD deficiency
13. AngiotensinAngiotensin
Angiotensinogen synthesized by liverAngiotensinogen synthesized by liver
Angiotensinogen to angiotensin I by Renin (10 AAs)Angiotensinogen to angiotensin I by Renin (10 AAs)
Angiotensin I to II by ACEAngiotensin I to II by ACE (Angiotensin converting enzyme)(Angiotensin converting enzyme)
Angiotensin II active form Have 8 AAsAngiotensin II active form Have 8 AAs
Vaso-constructor increase arterial pressureVaso-constructor increase arterial pressure
Increase synthesis of Aldosteron -Na+ retentionIncrease synthesis of Aldosteron -Na+ retention
ACE inhibitors used as antihypertensive & CCFACE inhibitors used as antihypertensive & CCF
14. OxytocinOxytocin
Hormone of posterior pituitaryHormone of posterior pituitary
ContainsContains 99 amino acidsamino acids
Stimulates contraction of uterusStimulates contraction of uterus
Hormone secreted by posterior pituitary
Contains 9 amino acids
Decreases GFR and retains body water
Increases Blood pressure
Vasopressin (ADH)Vasopressin (ADH)
15. CorticotropinCorticotropin
Hormone of Anterior pituitaryHormone of Anterior pituitary
ContainsContains 3939 amino acidsamino acids
Stimulates adrenal cortex for secretion of steroidStimulates adrenal cortex for secretion of steroid
hormoneshormones
TRHTRH
Hypothalamic hormoneHypothalamic hormone
ContainsContains 33 amino acidsamino acids
Stimulates release of thyrotropin from anteriorStimulates release of thyrotropin from anterior
pituitarypituitary
16. GastrinGastrin
Local hormone from StomachLocal hormone from Stomach
Stimulates production of gastric juiceStimulates production of gastric juice
SecretinSecretin
G I PeptideG I Peptide
Stimulates secretion of pancreatic juiceStimulates secretion of pancreatic juice
17. BradykininBradykinin
Contains 9 amino acidsContains 9 amino acids
Formed in bloodFormed in blood
Power full vasodilatorPower full vasodilator
Causes contraction of smooth musclesCauses contraction of smooth muscles
Stimulates pain receptorsStimulates pain receptors
EnkephalinsEnkephalins
Peptide formed in CNSPeptide formed in CNS
Binds to certain receptors in brain andBinds to certain receptors in brain and
induces analgesia (Killing pain sensation)induces analgesia (Killing pain sensation)
18. KallidinKallidin
Contains 10 amino acidsContains 10 amino acids
Power full vasodilatorPower full vasodilator
AspartameAspartame
Di-peptide,Di-peptide,
Neutra sweet, artificial sweetenerNeutra sweet, artificial sweetener
L aspartyl phenylalanyl methyl esterL aspartyl phenylalanyl methyl ester
Not suitable for phenylketourics.Not suitable for phenylketourics.
20. DeaminationDeamination
Removal of amino groupRemoval of amino group from amino acid byfrom amino acid by
enzyme to forms keto acidenzyme to forms keto acid
Deamination:1.Deamination:1. OxidativeOxidative deaminationdeamination
2.2. Non oxidativeNon oxidative deaminationdeamination
Glutamate α keto glutarate
NH2
Amino acid deaminase
21. TransaminationTransamination
Transfer of amino group of one amino acid to aTransfer of amino group of one amino acid to a
keto acidketo acid
Result in formation of new amino acid and a ketoResult in formation of new amino acid and a keto
acidacid
Enzymes : Transaminase orEnzymes : Transaminase or
Amino transferaseAmino transferase
Coenzymes : Pyridoxal phosphateCoenzymes : Pyridoxal phosphate
Advantage: Non essential amino acid synthesisAdvantage: Non essential amino acid synthesis
Interconversion of amino acidsInterconversion of amino acids
23. Reaction with ammoniaReaction with ammonia
Acidic amino acids reacts with NHAcidic amino acids reacts with NH33 to formto form
amide.amide.
They are part of protein structureThey are part of protein structure
Serve as source of NitrogenServe as source of Nitrogen
L- Glutamate
L- Glutamine
α keto glutarate
NH3NH3
Enzyme - Glutaminase
24. DesulphurationDesulphuration
Sulphur containing amino acid during theirSulphur containing amino acid during their
catabolism oxidises sulph-hydryl group to formcatabolism oxidises sulph-hydryl group to form
keto acid.keto acid.
C
COOH
CH2
SH
NH2H
SH2
COOH
CH3
NHC
COOH
CH2
NH2C
COOH
CH3
C O
Cysteine
Desulphurase
Imino acid
Keto acid
25. DecarboxylationDecarboxylation
Removal of coo group to form aminesRemoval of coo group to form amines
EnzymesEnzymes : Amino acid decarboxylase: Amino acid decarboxylase
CoenzymeCoenzyme : Pyridoxal phosphate: Pyridoxal phosphate
GlutamateGlutamate GABAGABA
NeurotransmitterNeurotransmitter
HistidineHistidine HistamineHistamine
Effect on BP, Allergic condEffect on BP, Allergic cond
TyrosineTyrosine TyramineTyramine
Contracts uterusContracts uterus
TryptophanTryptophan TryptamineTryptamine
Serotonin, NTSerotonin, NT
Decarboxylas
e
PLP
CO2
26. Colour reactions of amino acidsColour reactions of amino acids
Biuret reactionBiuret reaction Peptide bondsPeptide bonds
Ninhydrine reactionNinhydrine reaction Free amino groupsFree amino groups
Xanthoproteic reactionXanthoproteic reaction Aromatic amino acidsAromatic amino acids
Millon’s reactionMillon’s reaction TyrosineTyrosine
Hopkins – cole reactionHopkins – cole reaction Tryptophan – indole ringTryptophan – indole ring
Sakaguchi’s reactionSakaguchi’s reaction Arginine – guanidino groupArginine – guanidino group
Nitroprusside reactionNitroprusside reaction Free SH groupFree SH group
Pauly’s reactionPauly’s reaction Histidine – imidazole groupHistidine – imidazole group
Lead acetate reactionLead acetate reaction SH groupSH group
27. Biologically important compounds fromBiologically important compounds from
amino acidsamino acids
GlycineGlycine Heme, Purine base, Bile salt,Heme, Purine base, Bile salt,
GlutathioneGlutathione
Aspartic andAspartic and
Glutamic acidGlutamic acid
Purine, pyrimidine basesPurine, pyrimidine bases
TyrosineTyrosine Thyroxine, Adrenaline, Melaniine,Thyroxine, Adrenaline, Melaniine,
TryptamineTryptamine
TryptophaneTryptophane Niacin, SerotoninNiacin, Serotonin
Arginine,Arginine,
Methionine, GlycineMethionine, Glycine
CreatineCreatine
28. Last edited Nov 2018
1. Describe biomedical significance of five biologically active
peptides.
2. List two examples of dipeptide and their biomedical
importance.
3. List amino acids present in glutathione . Write its
significance.
4. What is ADH? Write its function.
5. Define Zwiter ion and write its significance.
6. Explain amphoteric nature of amino acid.
7. List Branched chain and Aromatic amino acids.
8. Describe classification of amino acids.