Question

lease help me loves.
a sample of white powder is given to you to identify. You may use the the Benedict test, the Lugol test, the Biuret test, and the Sudan Red test to identify it.
1.what will each test tell you?
2.If the white powder was an starch, how would each of the tests turn out?

Answer 1

What do you know about these tests?

Answer 2

The Benedict test will check for sugars. The Lugol test contains iodine and it turns starch black/ purple. The Biuret test tests for proteins and it turns purple. Finally the Sudan Red test tests for fats.

Answer 3

This is the uqestions
In a minimum of two paragraphs (10 + sentences), write what each test (Benedict, Lugol, Biuret, and Sudan Red) will tell you.

Answer 4

n a minimum of one paragraph (5 + sentences), describe how each test (Benedict, Lugol, Biuret, and Sudan Red) would turn out if each substance was a starch.

Answer 5

So you knew what the tests does, what's the problem? You could use google for reference btw

Answer 6

well idk how each test (Benedict, Lugol, Biuret, and Sudan Red) would turn out if each substance was a starch.

Answer 7

or what they will tell me im lost

Answer 8

If for example you use biuret's test for starch there won't be any result. You won't produce any colour change or any reaction happen

Answer 9

because it only checks for sugars?

Answer 10

Biuret detects presence of peptide bonds. Benedict's tests for reducing sugars

Answer 11

what would bendicts result be for starch nothing?

Answer 12

Starch is not reducing sugar but a polysaccharide. And yes, there is a way for benedict's to detect starch, and that is starch has to be hydrolysed to glucose first

Answer 13

the color would be brown for benedict right

Answer 14

Blue to Brick red if results are positive

Answer 15

ahh i need helping answering the questions above abt the white starch

Answer 16

Benedict test nothing happens or might make little change from teal to green because starch is not reducing sugar.
Lugol's test yields positive result from white to black
Biuret's test negative shows teal colour.

Answer 17

what about sudan red

Answer 18

Red dye will not stain or mix with starch and thus remains separated, if there is lipid or fat Sudan red with stain the fat molecule.

Answer 19

so this answers the white starch question right

Answer 20

Yes

Answer 21

A sample of a white powder is given to you to identify. You can use the Benedict test, the Lugol test, the Biuret test, and the Sudan Red test to identify it. Answer the questions to report on your analysis plan.

Answer 22

how do i answer this one needs two patagraphs
In a minimum of two paragraphs (10 + sentences), write what each test (Benedict, Lugol, Biuret, and Sudan Red) will tell you.

*You should set up your second paragraph by explaining the scenario you were put in*

Answer 23

so far i put this for that one
The Benedict test will check for sugars. The Lugol test contains iodine and it turns starch black/ purple. The Biuret test tests for proteins and it turns purple. Biuret detects presence of peptide bonds. Finally the Sudan Red test tests for fats.

Answer 24

idk what else to add hmm

Answer 25

You could add "if the results turned out negative, what will happen?" to your answer too

Answer 26

Add in the procedure of how you did the tests. Here are some material that could help you
http://www.cpet.ufl.edu/wp-content/uploads/2013/03/Identifying-Macromolecules-Lab.pdf

Answer 27

but i dont have to dot he porcedure aha its jst asking what i would do in that scenerio which idk

Answer 28

Yeah the question is asking you about the colour changes and why. Lets say we take Benedict's test for starch. Result will be negative and shows no change in colour from initial blue colour. Then explain why, you'll say because Benedict's tests reducing sugar, starch is non-reducing sugar and therefore doesn't produce any changes in colour

Answer 29

oh ok i get it now aha thanks very much !!

Answer 30

As for biuret's test for presence of peptide bond. Because starch is not a protein, and has not peptide bound,

Answer 31

no peptide bond, it produces no result for biuret's test with starch

Answer 32

yw :)

Answer 33

sam