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Methods:

Part 1: Carbohydrates

Investigation 1: Monosaccharides and Disaccharides

1. Before the experiment, potato suspension as prepared by crushing using the mortar.

!. "ix test tubes ere prepared.#. In a test tube, 1m$ of a 1% g$ucose so$ution as added.

&. "tep ! as repeated by adding 1m$ of ater, 'uice, soft drin(, potato suspension and

soy mi$( to each of the other five test tubes.). )m$ of Benedict*s so$ution as added to each six tubes.

+. hese six tubes ere incubated in the ater bath for #minutes.

-. he co$our changes of the so$ution ere observed and hether a precipitate has

formed as noted.

. he resu$ts ere recorded in a tab$e.

Investigation !: "tarch

1. ! m$ of starch so$ution, ater, 'uice, soft drin(, potato suspension and soy mi$( ere

added to + test tubes respective$y.

!. o each tube, ) drops of iodine reagent ere added and mixed e$$.#. he observations ere recorded.

Investigation #: /ydro$ysis of Carbohydrates

a) Hydrolysis1. + m$ of sucrose so$ution and ater ere added to test tube 1 and ! respective$y.

!. +m$ of the samp$es that shoed the negative resu$t in Investigation 1 ere added to

test # and &.#. # m$ of hydroch$oric acid as added to each tube and mixed e$$.

&. hese tubes ere put in the boi$ing ater for ) minutes.

b) Benedict’s test ). 0fter ) minutes of incubation, $ m$ of each samp$e ere transferred to ne test tubes

respective$y and added ith &m$ of Benedict*s so$ution.+. he observations ere recorded.-. he remaining test tubes ere continuing incubated for 1 minutes.

. 0fter 1 minutes, step ) as repeated by transferring the so$utions

2. he observations ere recorded.1. ) drops of iodine reagent ere added to test tubes in step .

11. he observations ere recorded.

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Part !: Proteins

1. ! test tubes ere prepared.

!. # m$ of 1% egg a$bumin and disti$$ed ater ere added to each test tube respective$y.

#. # m$ of concentrated potassium hydroxide ere added to both test tubes and mixed

e$$.

&. 1 m$ of .)% copper su$phate ere added to these to tubes.

). he observations ere recorded.

Part #: 3ipids

1. + sma$$ s4uares of bron papers ere prepared.

!. he papers ere $abe$$ed.

#. 0 tiny drop of vegetab$e oi$, disti$$ed ater, 'uice, soft drin(, potato suspension and

mi$( ere put onto the papers.

&. he drops ere rubbed gent$y ith different fingertips.). he spots ere a$$oed to dry.+. he observations ere recorded.

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5esu$t:

Part 16Investigation 17

Before incubation

0fter incubation

8uice

Mi$( Potato

suspension

"oft

drin( 

Positive

contro$

 9egative

contro$

8uice

Mi$( 

Potato sus pension

"oft drin( 

Positive contro$

 9egative

contro$

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Investigation !

Investigation #

0fter ) minutes incubation

0fter ) minutes incubation 6tested ith Benedict*s test7

Positive

contro$

Mi$( 

8uice

"oft drin( 

Potato

suspension

 9egative

contro$

Potato suspensionMi$( 

Positive

contro$ 9egative

contro$

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0fter 1 minutes incubation 6test ith iodine reagent7

Potato suspensionMi$( 

"oy mi$( Potato

sus ensionPotato suspension

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Part !

Disti$$ed ater 

0$bumin so$ution

"oft drin(  8uice

Potato suspension

Mi$( 

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Part #

Disti$$ed ater 

8uice"oft drin( 

egetab$e oi$

Potato suspension

"oy Mi$( 

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ab$e 1: Investigation 1

"amp$es Before incubation 0fter incubation Positive;9egative

5esu$t

Positive contro$ e$$o co$our  

so$ution formed

C$oudy b$ue so$ution

formed

 9egative

Potato suspension C$oudy vio$et co$our 

formed

C$oudy b$ue so$ution

formed

 9egative

 

ab$e !: Investigation !

"amp$es Co$our 0fter incubation Positive;9egative 5esu$t

Positive contro$ >e$$o co$our so$ution formed =

 9egative contro$ >e$$o co$our so$ution formed =

8uice he co$our remain unchanged 9egative

"oft drin( he co$our remain unchanged 9egative

"oy mi$( he co$our remain unchanged 9egative

Potato suspension Dar( b$ue so$ution formed Positive

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ab$e #: Investigation #

"amp$es Benedict*s test Iodine test

minutes

)minutes 1minutes

minutes

)minutes 1minutes

"oy Mi$( 9egativ

e

 9egative 9egative = = =

Potato

suspension

 9egativ

e

 9egative 9egative 9egativ

e

Positive 9egative

ab$e &: Part !

"amp$es Co$our changes Biuret*s test

?gg 0$bumin 0 vio$et co$our so$ution formed =

Disti$$ed ater 0 b$ue co$our so$ution formed. =

Mi$( 0 $ight purp$e so$ution formed Positive

"oft drin( 0 bron co$our so$ution formed 9egative

8uice 0 $ight orange so$ution formed 9egative

Potato 0 dar( vio$et co$our so$ution

formed

Positive

ab$e ): Part #

"amp$es