Chem Investigatory

Chemistry Investigatory project Analysis on Presence of Proteins in Different Food Items SUBMITTD T! Mrs# DI$"A %"!TI &A(!T'A

SUBMITTD B" D$&D'A "ADA$ C)ASS *+ A

Chemistry Investigatory Investigatory Project

CERTI FI CATE

This is to certify that D$&D'A "ADA$ a st,dent of class -II has s,ccessf,lly comp co mple lete ted d th the e re rese sear arch ch an analy alysis sis pr proj ojec ectt on the topic “Analysis of Food Stuff for the presence of Proteins” ,nder the g,idance of Mrs# DI$"A %"!TI &A(!T'A .S,/ject teacher0# This project is a/sol,tely gen,ine and does not ind,lge in plagiarism of any 1ind# The references ta1en in ma1ing this project has /een declared in /i/liography# .S,/ject Teacher0 Mrs.DIVYA JYOI !A$O%A

.Principal0 Mrs.!""#AM MA#VIYA

Chemistry Investigatory Investigatory Project

ACKNOWL EDGEMENT

2S,ccess is the progressive reali3ation of a 4orthy goal56 says o,r respected Principal5 I 4ish my deep gratit,de to my Principal Mrs# &)AM MA)$I"A 7 respected teachers Mrs# DI$"A %"!TI &A(!T'A5 4hose elo8,ent g,idance and val,a/le s,ggestions have /een indispensa/le in /ringing o,t this assigned project s,ccessf,lly# It is thro,gh there practical 1no4ledge5 there s,ggestion and help offered /y them from time to time that /ro,ght great confidence in ta1ing ,p this 4or1 and synchroni3ing my efforts in accomplishment of the project 4or1# I also e9press my gratit,de to the )a/oratory Assistant Mr#'amnarayan Sir5 4ho has greatly helped me in completion of e9periments and this project#

Chemistry Investigatory Project

I!D"& '() *hat are Proteins+ ,() *hat are A-ino Acids+ () Structures of Proteins. .'()Pri-ary Structure. .,() Secondary Structure. .() ertiary Structure. ./() 0uaternary Structure.

/()ypes of A-ino Acids. /.'()"ssential A-ino Acids /.,()Se-i "ssential A-ino Acids /.()!on "ssential A-ino Acids Chemistry Investigatory Project

1(2 Diseases caused 3y deficiency of Proteins. 1.'() Maras-us 1.,() 45ashior6or 1.() Deficiencies of Protein 7 and Protein S 1./() 7ache8ia

9() ests for Proteins. :()Sources of Proteins. :.'()Seafood :.,()*hite)Meat Poultry :.()Mil6; 7heese < Yo=urt :./()"== :.1()>eans :.9()Por6 enderloin Chemistry Investigatory Project

PROTEI NS

')*hat are protiens+ Proteins large /iomolec,les5 or macromolec,les5 consisting

of one or more long chains of amino acidresid,es# Proteins perform a vast array of f,nctions 4ithin organisms5 incl,ding catalysing

meta/olic

replication5 responding

to

reactions5 D&A

stim,li5

and transporting

molec,les from one location to another# Proteins differ from one another primarily in their se8,ence of amino acids5 4hich is dictated /y the n,cleotide se8,ence of their genes5

and

4hich

,s,ally

res,lts

in protein

folding into a specific three:dimensional str,ct,re that determines its activity#

A linear chain of amino acid resid,es is called a polypeptide# A protein contains at least one long polypeptide# Short polypeptides5 containing less than +;< Chemistry Investigatory Project

=; resid,es5 are rarely considered to /e proteins and are commonly called peptides5 or sometimes oligopeptides# The individ,al amino acid resid,es are /onded together /y peptide /onds and adjacent amino acid resid,es# The se8,ence of amino acid resid,es in a protein is defined /y the se8,ence of a gene5 4hich is encoded in the genetic code# In general5 the genetic code specifies +; standard amino acids> ho4ever5 in certain organisms the genetic

code

can

incl,de selenocysteine and?in

certain archaea?pyrrolysine# Shortly after or even d,ring synthesis5 the resid,es in a protein are often chemically modified /y post:translational modification5 4hich alters the physical and chemical properties5 folding5 sta/ility5 activity5 and ,ltimately5 the f,nction of the proteins# Sometimes proteins have non:peptide gro,ps attached5 4hich

can

/e

called prosthetic

gro,ps or cofactors#

Proteins can also 4or1 together to achieve a partic,lar


f,nction5 and they often associate to form sta/le protein comple9es#

!nce formed5 proteins only e9ist for a certain period of time and are then degraded and recycled /y the cell@s machinery thro,gh the process of protein t,rnover# A protein@s lifespan is meas,red in terms of its half:life and covers a 4ide range# They can e9ist for min,tes or years 4ith an average lifespan of *<+ days in mammalian cells# A/normal and or misfolded proteins are degraded more rapidly either d,e to /eing targeted for destr,ction or d,e to /eing ,nsta/le# )i1e

other

/iological

macromolec,les

s,ch

as polysaccharides and n,cleic acids5 proteins are essential parts of organisms and participate in virt,ally every process

4ithin cells#

Many

proteins

are en3ymes that catalyse /iochemical reactions and are


vital to meta/olism# Proteins also have str,ct,ral or mechanical f,nctions5 s,ch as actin and myosin in m,scle and the proteins in the cytos1eleton5 4hich form a system of scaffolding that maintains cell shape# !ther proteins are important in cell signaling5 imm,ne responses5 cell adhesion5 and the cell cycle# In animals5 proteins are needed

in

the diet to

provide

the essential

amino

acids that cannot /e synthesi3ed# Digestion /rea1s the proteins do4n for ,se in the meta/olism#

, )*hat are a-ino a-ino acids+ A-ino acids are /iologically important organic compo,nds containing amine .:&+0 and car/o9yl .: C!!0 f,nctional gro,ps5 along 4ith a side:chain .' gro,p0 specific to each amino acid#  The 1ey elements of an amino acid are car/on5 hydrogen5 o9ygen5 and nitrogen5 tho,gh other elements are fo,nd in the side:chains of certain amino acids# A/o,t ;; amino acids are 1no4n .tho,gh only +; appear in the genetic code0 and can /e classified in many 4ays# They can /e classified according to the core str,ct,ral f,nctional gro,ps@ locations as alpha: .:05 Chemistry Investigatory Project

/eta: .E:05 gamma: .:0 or delta: .G:0 amino acids> other categories relate to polarity5 p level5 and side:chain gro,p type .aliphatic5 acyclic5 aromatic5 containing hydro9yl or s,lf,r5 etc#0# In the form of proteins5 amino acids comprise the second:largest component .4ater is the largest0 of h,man m,scles5 cells and other tiss,es# !,tside proteins5 amino acids perform critical roles in processes s,ch as ne,rotransmitter transport and /iosynthesis#  2 S%?7?%" OF P%OI"!S

Most proteins fold into ,ni8,e =:dimensional str,ct,res# The shape into 4hich a protein nat,rally folds is 1no4n as its native conformation# Altho,gh many proteins can fold ,nassisted5 simply thro,gh the chemical properties of their amino acids5 others re8,ire the aid of molec,lar chaperones to fold into their native states# Biochemists often refer to fo,r distinct aspects of a protein@s str,ct,reH .'()Pri-ary structure () The amino acid se8,ence# A protein is a polyamide# .,() Secondary structure () 'eg,larly repeating local str,ct,res sta/ili3ed /y hydrogen /onds# The most common e9amples are the :heli95 E:sheet and t,rns# Beca,se secondary str,ct,res are local5 many regions of


different secondary str,ct,re can /e present in the same protein molec,le# .() ertiary structure () The overall shape of a single protein molec,le> the spatial relationship of the secondary str,ct,res to one another# Tertiary str,ct,re is generally sta/ili3ed /y nonlocal interactions5 most commonly the formation of a hydropho/ic core5 /,t also thro,gh salt /ridges5 hydrogen /onds5 dis,lfide /onds5 and even posttranslational modifications# The term tertiary str,ct,re is often ,sed as synonymo,s 4ith the term fold # The tertiary str,ct,re is 4hat controls the /asic f,nction of the protein# ./() 0uaternary structure () The str,ct,re formed /y several protein molec,les .polypeptide chains05 ,s,ally called protein s,/,nits in this conte9t5 4hich f,nction as a single protein comple9#

Proteins are not entirely rigid molec,les# In addition to these levels of str,ct,re5 proteins may shift /et4een several related str,ct,res 4hile they perform their f,nctions# In the conte9t of these f,nctional rearrangements5 these tertiary or 8,aternary str,ct,res are ,s,ally referred to as conformations5 and transitions /et4een them are called conformational changes# S,ch changes are often ind,ced /y the /inding of Chemistry Investigatory Project

a s,/strate molec,le to an en3yme@s active site5 or the physical region of the protein that participates in chemical catalysis# In sol,tion proteins also ,ndergo variation in str,ct,re thro,gh thermal vi/ration and the collision 4ith other molec,les# Proteins can /e informally divided into three main classes5 4hich correlate 4ith typical tertiary str,ct,resH glo/,lar proteins5 fi/ro,s proteins5 and mem/rane proteins# Almost all glo/,lar proteins are sol,/le and many are en3ymes# Fi/ro,s proteins are often str,ct,ral5 s,ch as collagen5 the major component of connective tiss,e5 or 1eratin5 the protein component of hair and nails# Mem/rane proteins often serve as receptors or provide channels for polar or charged molec,les to pass thro,gh the cell mem/rane# A special case of intramolec,lar hydrogen /onds 4ithin proteins5 poorly shielded from 4ater attac1 and hence promoting their o4n dehydration5 are called dehydrons#


/ 2 ypes of a-ino acids Amino acids are organic compo,nds 4hich contain at least one amino gro,p .:&+0 and a car/o9y .:C!!0 gro,p# In the h,man genome5 +; amino acids are created to /,ild proteins and therefore termed proteinogen# Besides this5


there are appro9imately +; amino acids 4hich do not form proteins# These are ,sed to form s,gar for e9ample# The +; proteinogen amino acids are also called standard amino acids5 4hich can /e divided into three gro,psH essential5 semi:essential and non:essential# /.'() "SS"!IA# AMI!O A7IDS() ight amino acids are essential for h,mans5 as the /ody cannot prod,ce them /y themselves5 and they have to /e s,pplied e9ternally# These are( isoleucine; leucine; lysine; methionine; phenylalanine; threonine; tryptophan and @aline. /.,() S"MI "SS"!IA# AMI!O A7IDS() Arginine and histidine form the gro,p of so:called semi:essential amino acids# They have to /e cons,med in the diet ,nder certain circ,mstances# /.() !O! "SS"!IA# AMI!O A7IDS() The ten non:essential amino acids are a/le to /e prod,ced in the /ody# The follo4ing amino acids fall into this categoryH alanine; aspara=ine; aspartic acid; cysteine; gl,tamine; =luta-ic acid; =lycine; proline; serin and tyrosine. It sho,ld /e noted that the gro,ping JessentialK and Jnon: essentialK does not mean that one gro,p more important is that the other# This is /eca,se the division of the t4o does not assess 4hether the /ody has s,fficient s,pply of Chemistry Investigatory Project

the amino acids in 8,estion at its disposal# The protein re8,irement can differ greatly from person to person# The amo,nt of semi:essential and non:essential amino acids prod,ced /y the /ody itself depends on many different factors5 s,ch as age5 mental andLor physical stress or distress sit,ations# These determine the vario,s amino acid levels re8,ired to stay fit and healthy# 1 2 Diseases caused 3y deficiency of proteins 1.'() Maras-us

Marasm,s is a disease ca,sed /y a severe deficiency of protein and calories that affect infants and very yo,ng children5 often res,lting in 4eight loss and dehydration# Marasm,s can develop into starvation and ca,se fatality ca,sed /y a lac1 of essential n,trients# People 4ith marasm,s appear /ony 4ith little m,scle tiss,e5 according to FoodAfrica# 1.,() 45ashior6or

N4ashior1or is a disease ca,sed /y a severe deficiency of protein in diets that contain calories mostly from car/ohydrates s,ch as yams5 rice and /ananas# It ,s,ally affects older children# People 4ith 14ashior1or appear p,ffy in the a/domen area from retention of fl,id5 according to the University of Maryland Medical Center# Common symptoms of /oth marasm,s and 14ashior1or Chemistry Investigatory Project

incl,de fatig,e5 irrita/ility5 diarrhea5 st,nted gro4th and impairment of cognition and mental health# 1.() Deficiencies of Protein 7 and Protein S

Deficiencies of protein C and protein S are inherited conditions that ca,se a/normal /lood clotting5 according to Medline Pl,s# Deficiency of protein C occ,rs in a/o,t * o,t of =;; people# Deficiency of protein S affects * in +;5;;; people# Symptoms for these deficiencies incl,de redness5 pain5 tenderness or s4elling in the affected area# People 4ith these protein deficiencies need to /e caref,l a/o,t activities that increase ris1 of /lood clots5 s,ch as prolonged sitting5 /ed rest5 and long:time travel in cars and airplanes# 'esearch /y A# ooda p,/lished in the Annals of Indian Academy of &e,rology in +;;O discovered that protein S deficiency ca,ses ischemic stro1e# 1./() 7ache8ia

Cache9ia is a condition that involves protein deficiency5 depletion of s1eletal m,scle and an increased rate of protein degradation5 according to research /y D#P# Notler p,/lished in the Annals of Internal Medicine in +;;;# Cache9ia ca,ses 4eight loss and mortality and is associated 4ith cancer5 AIDS5 chronic 1idney fail,re5 heat disease5 chronic o/str,ctive p,lmonary disease and Chemistry Investigatory Project

rhe,matoid arthritis5 according to %## Morley in the American %o,rnal of Clinical &,trition# Patients 4ith malignant cancer of the stomach5 colon5 liver5 /illiary tract and pancreas e9perience ,nder n,trition from red,ced inta1e of protein5 calories and micron,trients5 and have fatig,e and a negative nitrogen /alance as a res,lt of loss of m,scle mass from cache9ia5 according to %# !c1enga in Alimentary Pharmacology and Therape,tics in +;;# 9()ests for Proteins in food ite-s (

The presence of Proteins in food st,ffs can /e detected /y performing follo4ing tests H - -anthoprotein test - Bi,ret test - MillionKs test - &inhydrin test :()Sources of Proteins.

#*H:Seafood Seafood is an e9cellent so,rce of protein /eca,se it@s ,s,ally lo4 in fat# Fish s,ch as salmon is a little higher in fat5 /,t it is the heart:healthy 1indH it has omega:= fatty acids#


#+H:Qhite:Meat Po,ltry Stic1 to the 4hite meat of po,ltry for e9cellent5 lean protein# Dar1 meat is a little higher in fat# The s1in is loaded 4ith sat,rated fat5 so remove s1in /efore coo1ing# #=H:Mil15 Cheese5 and "og,rt &ot only are dairy foods li1e mil15 cheese5 and yog,rt e9cellent so,rces of protein5 /,t they also contain val,a/le calci,m5 and many are fortified 4ith vitamin D# Choose s1im or lo4:fat dairy to 1eep /ones and teeth strong and help prevent osteoporosis# #H:ggs ggs are one of the least e9pensive forms of protein# The American eart Association says normal healthy ad,lts can safely enjoy an egg a day# #H:Beans !ne:half c,p of /eans contains as m,ch protein as an o,nce of /roiled stea1# Pl,s5 these n,tritio,s n,ggets are loaded 4ith fi/er to 1eep yo, feeling f,ll for ho,rs# #RH:Por1 Tenderloin This great and versatile 4hite meat is =* leaner than it 4as +; years ago#


EXPERI MENT

AIM() To analy3e the presence of proteins in a sample of Soy3eans; "== 5hite; !uts; >read.

APPA%A?S %"0?I%"D()  Test

t,/es  Test t,/e stand

7"MI7A#S %"0?I%"D()  'eagents



as re8,ired for testing and analysis of proteins for vario,s test# A sample of ta1en food in cr,shed 4ith 4ater #

P%O7"D?%"() Bi,ret Test H  Ta1e +ml meshed sample of ta1en food in a test t,/e#  Add fe4 drops of sodi,m hydro9ide sol,tion# Add very dil,te sol,tion of copper s,lphate drop::4ise# &ote the o/servation# The appearance of violet colo,r confirms the presence of proteins# -anthoprotein Test H  Ta1e +ml meshed sample of ta1en food in a test t,/e#  Add fe4 drops of +ml of conc# &itric acid# Sha1e for some time and 1eep aside# 


 &ote

the o/servation# The appearance of deep yello4 colo,r confirms the presence of proteins# &inhydrinKs TestH: Ta1e +ml meshed sample of ta1en food in a test t,/e# 

 Add

+ fe4 drops of &inhydrin Sol,tion and /oil the content#

 &ote

the o/servation# The appearance of intense /l,e colo,r confirms the presence of proteins#

MillonKs TestH: 

Ta1e +ml meshed sample of ta1en food in a test t,/e#

 Add

+ drops of MillonKs 'eagent and /oil the content#  &ote the o/servation# The 4hite ppt changes to /ric1 red on /oiling# O>S"%VAIO!S( Sn. est perfor-ed '. >uiret est ,. .

/.

Soya3ean "== >read 5hite Violet Violet Violet colour colour colour &anthoprotein Yello5 Yello5 Yello5 test ppt ppt ppt !inhydrin Intense Intense Intense est 3lue 3lue 3lue colour colour colour MillionBs est >ric6 red >ric6 >ric6 ppt red ppt red ppt


!uts Violet colour Yello5 ppt Intense 3lue colour >ric6 red ppt

Inference Protein Present Protein Present Protein Present Protein Present

%"S?#S < 7O!7#?SIO! () D,ring

the

analysis

e9periment5

the

given sample of Soy3eans; !uts; >read; "== 5hite the contain the Proteins


>I>I#IO$%APY  &C'T

Te9t /oo1 on Chemistry

 Together

 Arya

4ith )a/ Man,al Chemistry : Class < -II

P,/lications on Chemistry la/oratory Man,al

 Dictionary

of Science



444#Qi1ipedia#com  444#google#com  444#scri/d#com  444#amrita#ola/s#ed,#in


Chem Investigatory

Recommend Documents