Summary Topic 2: Biological Molecules Notes

2. Britogiant Molecules

2. 1
Testing for bwiogical molecules



Describe and out the
Benedict test for reducing sugars the iodine test for starch the emulsion test for lipids and the
's
carry , ,




furrier's less for proteins
Describe and carry out semi guanidine Benedict 's test
a -




reducing sugar solution by standardising the test and using the
on a



results to emmine the concentration



the Benedict 's Test
for reducing sugars

→ And Benedict 's reagent into test tube to a
sample

→ Heat in water bath
for 5 minutes
[positive if solution
→
Reducing sugar test] turns brick red
-




semi quunhhie
degree of change helps inihuire how the concentration of carbohydrate
test the colour
strong
-

as


is



The Emulsion Test
for Lipids↳ non-polar

→ Add 1 I pour ethanol and distilled water
:




→ Shake


→ Milky -


white emulsion


The Iodine Test
for
starch


→ Few drops of potassium iodide in
sample
Blue black colour
→ change
-




The Driver Test
for Proteins
→ Add a
few drops of Bruner 's solution to
sample

→ violet colour
change

, Dennis and
carry
out a test to
identify the presence of non reducing sugars using acid hydrolysis and Benedict's
-


,




solution


' ' '


sugars classified reducing ontheir
ability
'
are
reducing↳ to donate electrons
or non
-




↳ able to donate nor able to donate

Test .




→ add HU to
sample

→ boil in bath
for 5
water minutes



→ neutralise with sodium carbonate Calnan )
hydrogen
→ use litmus paper Cshjwrly alkaline conditions needed)
→ add Benedict's reagent

in water bath
→ hear


+ brick-red
positive colour change
Explanation .




→ arid
hydrolysis any glycosidic bonds



allowing precipitate form
monosaccharides are able to donate elections , to
→
remaining
2.2
Carbohydrates and Lipids

Describe and draw the
ring forms of
a -




glucose
and
p ghuose
-




a- Glucose
at.at
(add the H 's) 13 glucose
-




CH,OH




i
-




-




^
OH
OH
OH OH

OH

OH




difference
only

?⃝