Unit 1 biomolecules

Biochemistry Unit I
II semester First year

1. Biomolecules
Mrs. D.M. Kulkarni
Assistant professor
Yash institute of pharmacy,
Aurangabad

2. Definition, types, introduction, biological role
There are 5 categories of macromolecules:
Carbohydrates
Amino acids,
Proteins,
Lipids,
Nucleic acids
CONTENTS

3. Biomoleculesare Chemicals or molecules present in the living
organisms
Cellular pool is sum total of different types of biomolecules,
compounds and ions in a cell
Biomoleculesare compounds of carbon, Hydrogen,
Nitrogen,Oxygen
Hence the chemistry of living organisms is organized around carbon
Carbon is the most versatile and the most predominant element of
life.
All bio-molecules are polymers.
They make up living organisms.

4. Minerals
Gases
Water
Sugars
Aminoacids
nucleotides
Carbohydrates
Lipids
Proteins
Nucleicacids
Micromolecules
Small sized, low mol wt
Between18and800daltons
Foundintheacidsolublepool
Macromolecules
Large sized, high mol wt
Above10000daltons
Foundintheacidinsolublepool
BIOMOLECULES

5. Biomolecule Buildingblock Majorfunctions
PolysaccharideMonosaccharide Storageformofenergy
Protein Aminoacid Basicstructureandfunction ofcell
Lipids Fatty acids&glycerol Storageformofenergyto meet
longtermdemands
MajorComplexBiomoleculesofCell
DNA Deoxyribonucleotide Hereditaryinformation
RNA Ribonucleotide Proteinsynthesis

6. CARBOHYDRATES
Carbohydratesarethemostabundantorganic
moleculesinnature.
Thetermcarbohydrateis derivedfromtheFrench
term
hydratedecarbonei.e.it isahydrateof carbonor
C
n(H
2O)
n
organicsubstanceshavingC,H &O WhereinH
andO are intheratio 2:1as found inH
2O
Carbohydrates aredefinedas Poly hydroxy
aldehydesor ketonesor the substances which
obtain them upon hydrolysis

7. FUNCTIONSOFCARBOHYDRATES
-Mostabundantsourceof energy(4cal/g)
-Precursorsformanyorganiccompounds(fats,amino
acids)
-Presentasglycoproteinsand glycolipidsinthecell
memebraneandfunctions such ascellgrowthand
fertilization
-Presentasstructuralcomponentslike cellulosein
plants, exoskeletonof some insects,cell wallof
microorganisms
-Storageform ofenergy(glycogen)tomeettheenergy
demands ofthebody.

8. CARBOHYDRATES
MONOSACCHARIDES
OLIGOSACCHARIDES
POLYSACCHARIDES
Basicunitsofcarbohydrates
Cannot be hydrolysed into
smallerunits
canbefurther
hydrolysed
Noncrystalline,nonsoluble
in water, tasteless, on
hydrolysis gives mol of
monosaccharides
e.g.starch,cellulosea.Basedontheno.of
C-atoms
a.Basedonthetypeof
functionalgroup
a.Disaccharides
b.Trisachharides
c.Tetrasachharides

9. MONOSACCHARIDES
Basedon the noofC-atoms
-Trioses(C
3H
6O
3)
e.g.Glyceraldehyde,
Dihydroxyacetone
-Tetroses(C
4H
8O
4)
e.g.Erythrose,Threose
-Pentoses(C
5H
10O
5)
e.g. Ribulose, Xylose
Arabinose
(deoxyribose–C
5H
10O
4)
-Hexoses(C
6H
12O
6)
e.g. glucose, fructose
galactose,mannose
-Heptoses(C
7H
14O
7)
e.g.sedoheptulose
glucoheptose
Basedonthe
functionalgroup
-Aldoses:thefunctional
groupis Aldehyde–CHO
e.g.Glyceraldehyde,
glucose
-Ketoses:thefunctional
groupisketone
(C =O)
e.g. Dihydroxyacetone,
fructose

10. DerivativesofMonosaccharides
1.DeoxySugars:
2.AminoSugars:
3.SugarAcid:
Deoxygenation of ribose produces deoxyribose,
whichisa structuralcomponentofDNA
When 1 or more –OH groups of monosaccharides
are replaced by –NH
2(amino group) it forms an
aminosugare.g. Glucosamine, which forms
chitin,fungalcellulose,hyaluronicacid.
Oxidationof–CHOor–OH group formssugar
acids.Ascorbicacidisasugar acid
4.Sugaralcohols: Reductionof aldosesorketoses.
GlycerolandMannitol.

11. OLIGOSACCHARIDES
Theyareformedbycondensationof2-9monosaccharides
Dependinguponthe no. ofmonosachharidemoleculestheyare:
a.Disaccharides(sucrose,lactose)
b.Trisaccharides(raffinose)
c.Tetrasaccharides(stachyose)
The smallestandthecommonestoligosaccharidesareDisaccharides

12. DISACCHARIDES
A disaccharide consists of 2 monosaccharide units (similar or dissimilar)
heldtogetherbyaglycosidicbond
Theyarecrysatalline,watersoluble andsweettotaste.
MALTOSE :-isalsocalledas maltsugar.
-made upof2glucose molecules
LACTOSE:-is also called as milk sugar as it is found naturally in
milk
-made upofglucoseandgalactose
-souringofmilkisdue to conversionoflactoseto
lacticacid
SUCROSE :-isalsocalledas canesugar.Itisthesugarfoundin
sugarcaneandsugarbeet
-mostabundantamongnaturallyoccuringsugars.
-Important sourceof Dietarycarbohydrates
-made upofglucoseandfructose

13. POLYSACCHARIDES
-AlsocalledasGLYCANS
-Madeupofrepeatingunits ofmonsaccharidesheld byglycosidic
bonds
-During its formation a water molecule is released at each
condensation
Thishelpsreducethebulkmaking it almostinsoluble
decreasingitseffectonthewaterpotentialorosmoticpotentialof
thecell
-Unlikesugarstheyarenotsweet.
-They areidealasSTORAGEAND ASSTRUCTURAL COMPONENTS
-Theyare of2typesHomoglycans andHeteroglycans.
HOMOGLYCANS
-Made up of only 1 type of
monosaccharidemonomers
-Foregstarch, glycogen,
cellulose
-Glucan(made upofglucose)
-Fructan(madeupoffructose)
-Galactan(made upofgalactose)
HETEROGLYCANS
-Made up condensation of2 or
moretypes ofmonosaccharides
-ForegHyaluronicacid,agar,
Chitin,peptidoglycansetc

14. Polysaccharides
Starch structure vsGlycogen structure

15. STORAGE
POLYSACCHARIDES
STARCH
1.Carbohydratereserveofplantsandthemostimportantdietarysource
foranimals
2.Highcontentofstarchincereals,roots,tubers,vegetablesetc.
3.HomopolymermadeupofGLUCOSE units.AlsocalledasGLUCAN.
4.Starch=Amylose+Amylopectin(polysaccharidecomponents)
GLYCOGEN
1.Carbohydratereserveinanimals.Hencereferredasanimalstarch
2.HighconcentrationinLiver,musclesandbrain.
3.Alsofoundinplantsthatdonothavechlorophyll(yeastandfungi)
4.GLUCOSE istherepeatingunit.
INULIN
1.Polymerof fructosei.e.fructosan
2.FoundinDahlia,bulbs,garlic,onionetc
3.Easilysolubleinwater
4.Inulinisnotreadilymetabolisedinthe humanbodyandisreadilyfiltered
throughthekidney.Henceusedfortestingkidneyfunction(GFR)

16. STRUCTURAL
POLYSACCHARIDES
CHITIN
1.Secondmostabundantorganicsubstance.
2.ComplexcarbohydrateofHeteropolysaccharide type.
3.Foundinthe exoskeletonsofsomeinvertebrateslikeinsectsand
crustaceans.Providesbothstrengthandelasticity.
4.Becomeshardwhenimpregnatedwithcalciumcarbonate.
CELLULOSE
1.Occursexclusivelyinplantsandisthemostabundantorganic
substanceinplantkingdom.
2.Predominantconstituentofplantcellwall.
3.Itistotallyabsentinanimals.

17. Polysaccharides: Cellulose structure

18. Proteins

19. PROTEINS
Mostabundantorganic moleculesofthelivingsystem.
They formabout 50%ofthedry weightofthecell.
Theyaremost importantforthearchitecture andfunctioning
ofthecell.
Proteinsarepolymersofamino acids
Proteinson completehydrolysisyields AminoAcids
Thereare 20standardaminoacidswhicharerepeatedlyfound
in thestructureof proteins–animal,plantormicrobial.
Collagenis themostabundantanimalproteinandRubisco is
the mostabundantplant protein
ProteinSynthesisiscontrolledby DNA.

20. AMINOACIDS
Amino acids are group of organic compounds
having2 functionalgroups(-NH
2)and(-COOH)
(-NH
2)group isbasicwhereas(-COOH)isacidic
R-canbeHinglycine,CH
3 inalanine,Hydroxymethylinserine
inothersitcan be hydrocarbonchainoracyclicgroup
AllaminoacidscontainC, H, O and Nbutsomeofthemadditionally
containS
Physical and chemical properties of amino acids are due to
amino, carboxylandRfunctionalgroups
Aminoacidsaredifferentiatedinto 7groups

21. No. Nature Aminoacids
1. NEUTRAL : Aminoacidswith1aminoand1
carboxylgroup
Glycine(Gly),Alanine(Ala),
Valine (Val), Leucine (Leu),
Isoleucine(Ile)
2. ACIDIC:1extracarboxylgroup Aspartic acid (Asp),
Asparagine(Asn),Glutamic
acid(Glu),Glutamine(Gln)
3. BASIC:1extraaminogroup Arginine(Arg),Lysine(Lys)
4. S–CONTAINING :Aminoacidshave sulphurCysteine(Cys),Methionine
(Met)
5. ALCOHOLIC : Aminoacidshaving–OHgroup Serine(Ser),Threonine
(Thr),Tyrosine(Tyr)
6. AROMATIC :Aminoacidshavingcyclic
structure
Phenylalanine(Phe),
Tryptophan(try)
7. HETEROCYCLIC :aminoacidshavingN in
ringstructure
Histidine(His),Proline(Pro)

22. Asparticacid(acidic)
Alanine
(neutral)
Lysine(basic)
Serine(alcoholic)
Cysteine(suphur)Phenylalanine(aromatic)

23. PEPTIDE
FORMATION
Aminoacidsarelinkedseriallyby
peptide bonds(-CONH-)formedbetween
the
(-NH2)ofoneaminoacidandthe
(-COOH)ofadjacentaminoacid
Chain having 2 amino acids linked by
a peptidebondiscalledasa
DIPEPTIDE
Thesequenceofaminoacidspresent
inapolypeptideisspecificfora
particularprotein.

24. STRUCTUREOF
PROTEIN
4 basic structural levels are assigned to
proteins –primary,secondary,tertiary
andquaternary
PRIMARY
Theprimary structurereferstothenumber
and linear sequence of amino acids in the
polypeptide chain and the location of the
disulphidebridges
Theprimarystructureisresponsiblefor the
functionof theprotein.
The N-terminal amino acid is written on the
left side whereas the C-terminal amino acid
iswrittenon therightside

25. SECONDARY
The folding of the linear chain into a specific coiled
structureis called as secondarystructure.
3types:α-helix,β-pleatedsheetandcollagen
helix
α-helix β-pleatedsheet Collagenhelix

26. TERTIARY
The helicalpolypeptidemay fold uponitselfandassumeacomplexbut
specificform–spherical,rodlikeorsomethinginbetween.
Thesegeometricalshapesareknownas tertiary(3
0
) structure
QUATERNARY
Proteinsaresaidto be quaternaryinstructure
Ifthey have2 ormorepolypeptidechains
Haemoglobin isan excellentexample

27. PROTEINS
Function
Chemicalnature
andsolubility
Nutritional
importance

28. Functional
classification
Structuralproteinse.g.keratin,collagen
Enzymaticproteinse.g.pepsin
Transportproteinse.g.Haemoglobin
Hormonalproteinse.g.Insulin,Growthhormone
Contractileproteinse.g.Actin,myosin
Storageproteinse.g.Ovalbumin
Geneticproteinse.g.Nucleoproteins
Defenceproteinse.g.Imunoglobulins
Receptorproteinse.g. forhormonesandviruses

29. Classification based on
chemical nature and
solubility
1.Simpleproteins: Theyarecomposedonlyofaminoacid
residues
2.Conjugatedproteins:Alongwithaminoacids ,thereis a
non-proteinprostheticgroup.
3.Derivedproteins: Theyaredenaturedordegradedproducts
oftheabovetwo

30. Proteins
Simple
Conjugated
Derived
Nucleoproteins
Glycoproteins
Mucoproteins
Lipoproteins
Phosphoproteins
Chromoproteins
Metalloproteins
Globular Fibrous
Albumin
Globulin
Histones
Collagen
Elastin
Keratin
Primary Secondary
Metaproteins
Coagulated
proteins
Proteans
Proteoses
protones
Peptides

31. There are at least 7 functions of proteins
Enzyme catalysts –specific for 1 reaction
Defense –antibody proteins, other proteins
Transport-Hgb, Mgb, transferrins, etc
Support –keratin, fibrin, collagen
Motion –actin/myosin, cytoskeletalfibers
Regulation-some hormones, regulatory proteins
on DNA, cell receptors
Storage –Ca and Fe attached to storage proteins

32. Withthe water,Isay,Touchmenot,
Tothetongue,Iamtasteful,
Withinlimits,Iamdutiful,
Inexcess,Iamdangerous
LIPIDS

33. Lipids arethechiefconcentratedstorageformofenergyforming
about3.5%of thecellcontent.
Lipidsareorganic substancesrelatively insolubleinwaterbut
solubleinorganicsolvents(alcohol,ether)
Functions:
1.They aretheconcentratedfuel reserveof thebody.
2.Lipids areconstituentsofmembrane structureandregulatethe
membrane permeability.
3.Theyserveassourceoffatsolublevitamins
4.Lipidsareimportantcellularmetabolicregulators
5.Lipdsprotecttheinternalorgansandserveasinsulatingmaterials

34. LIPIDS
Simple
Complex
Derived
Phospholipids
Glycolipids
Lipoproteins
Fats&Oils Waxes
Steroids
Terpenes

35. SIMPLELIPIDS
They areestersoffattyacidswith alcohol.Theyareof2 types:
1.Neutralortruefats:Estersoffattyacidswithglycerol
2.Waxes: Estersof fattyacidswith alcoholotherthanglycerol.
Neutral/True
fats
True fats are made up of C, H, & O but O is less
Afatmolecule ismadeup of 2components:
a)GLYCEROL
b)FATTYACIDS(1-3mol,of sameordifflongchained)

36. Glycerol
Aglycerolmolhas3 carbonseach bearinga
–OHgroup
Fattyacid
Afattyacidmolis anunbranchedchainofC-
atoms.
Ithasa–COOH group atoneendandaH
bonded to almost alltheC-atoms
Fattyacidsmaybesaturatedorunsaturated

37. WAXES
Lipids which are long chain saturated fatty acids and a long chain
Saturatedalcoholofhighmolwt otherthan glycerol
Example:
1.Beeswax:secretionofabdominal glandsof workerhoney bees
2.Lanolin or wool fat:Secretion of cutaneous glandsandobtained
fromthe woolofsheep
3.Sebum:secretion ofsebaceousglandsof skin
4.Cerumen:soft and brownishwaxysecretionoftheglandsin the
externalauditorycanal.Alsocalledas Earwax
5.Plantwax: Coatingformedontheplantorganstoprevent
transpiration
6.Paraffinwax:Atranslucentwaxysubstanceobtainedfrom
petroleum

38. COMPLEX
LIPIDS
They are derivatives of simple lipids having
additionalgrouplikephosphate,N
2-base,
Proteinetc.They are furtherdividedinto
Phospholipids,Glycolipids, Lipoproteins.
Phospholipid
Theyaremadeup ofamoleculeofglycerol
Orotheralcoholhaving
1.Aphosgroupat1ofits–OHgroups
2.2 fatty acid molecules at other 2 –OH
groups
3.Anitrogencontainingbaseattatchedto
phosgroup
A phospholipid molecule has a
hydrophobictail(fattyacids) anda
hydrophilichead(phosgroup)

39. Glycolipid
They are components of cell
membranes, particularly myelin
sheathandchloroplastmembranes
CEREBROSIDE arethemost
simplest form ofglycolipids

40. Lipoprotein
Theycontainlipidsandproteinsintheirmolecules.
They are mainconstituent ofmembranes.
TheyarefoundinmilkandEggyolk.
Lipidsaretransportedinbloodandlymphaslipoproteins.
5typesof lipoproteins:
1.chylomicrons
2.VLDL
3.LDL
4.HDL
5.Freefattyacidalbumincomplex

41. DERIVED
LIPIDS
They are derivatives obtained on the
hydrolysisofthesimple andcomplexlipids.
e.g. steroids,terpenesandprostaglandins
Steroid
Thesteroidsdonotcontainfattyacids
butareincludedinlipidsastheyhave
fat-likeproperties.
They are made up of 4 fused carbon
rings
Cholesterol, Vit D, testosterone,
adrenocorticalhormones.
Themostcommonsteroids are
STEROLS.
Commonsterolsare Cholesteroland
ergosterol

42. Terpenes
Terpenesareamajorcomponentof essentialoilsproducedby
plants.Theygivefragrance totheplantparts.
Vitamins A, E and K contain a terpenoid called phytol
Carotenoidpigmentis precursorforVitaminA
Lycopene,apigmentpresentintomatoesisaterpenoid
Gibberellins,theplanthormoneis alsoaterpene

43. NUCLEOTIDES

44. SUGAR
N2BASES

46. dr.aarif
DNA

49. m-RNA r-RNA t-RNA

50. References :
1. BiomoleculesRahna.K.RathnanAssistantprofessor
SahrdayaCollegeof engineeringandtechnology
2. PurinCharoensuksai, PhD Department of Biopharmacy,
Faculty of Pharmacy, SilpakornUniversity