Experiment On Protein: Biuret Assay

Protein are organic compounds made up of amino acid arranged in a linear chain. For this experiment, we need to determine protein concentrations. There are a few method for determining the protein concentrations. The methods are Biuret Assay, Lowry Assay, Bradford Assay. But for this experiment, we only use Biuret Assays to determine the protein concentration.


This method is based on interaction of the Cu2+ with protein in alkaline solution and the concentration of protein is absorbed at 540nnm, A540 by an apparatus known as spectrophotometer.


The result of this experiment will show by plotting a standard graph between the absorbance of light at 540nm and the concentration of protein in the assay. From the graph, the unknown concentration of protein will be determine.











Due to the equation, y=0.0333x+0.1107 which is a gradient equation from the plotting graph, we make a table to show the value of concentration of protein (mg/ml) for each sample and from this graph we will see a difference value of protein’s concentration.


From the graph plotting at the end of this experiment, we found that the high concentration of protein is obtain from the sample B, which is also known as a Grade B of an egg. The value of the concentration of that egg is 17.82 mg/ml. For the sample A (Grade A of an egg) which is assumed by most of the consumer as the best choice, the value of its concentration is only 14.42 mg/ml. From that, it is shown that Grade A of an egg has a lower value of concentration of protein compare to the Grade B of an egg which is rich in protein.
The lowest value concentration of protein among four samples is a sample C (Grade C of an egg), which is shown by both table and bar graph as 10.79 mg/ml. As we compare to the concentration of protein in sample X, which is may be not an hen’s egg, the concentration of protein is high compared to Grade C, and lower than the concentration from Grade A and Grade B.


As a conclusion from the result obtain, we know that the concentration of a protein of an egg is not depend to the grade of an egg. The basic choice of choosing an egg is based on the quality and size. Eggs can be sorted into five different sizes according to weight, for example are Jumbo, Extra Large, Large, Medium, Small, and Pee Wee. Nutritional values contain in Jumbo size has a high concentration of protein compared to the other sizes and the lowest nutritional values is a Pee Wee size


If a consumer gets its protein by only consuming an egg from the Grade C, it is not enough for his/her diet. A deficiency of protein in a body can cause a disease known as kwashiorkor. A consumer will also have a high possibility in having a disease if he/she only gets his/her protein through consuming an egg from Grade B which have a high level concentration of protein.

writter: Nurul Fareha Bt Muhamad Daut (D20071029515)

Lab Member:
Nurul Fareha Bt Muhamad Daut (D20071029515)
Nor Hafizah Bt Abd Rahim (D20071029514)
Nor Hidayah Bt Shaari (D20071029446)
Nor Farahana BT Adnan (D20071029444)

What is the function of amino acids in living things?

Brain FEST
Chapter 2: Protein and its metabolism
What is the function of amino acids in living things

Amino acids is a chemical unit or “building blocks” of the body that make up proteins. In another word it is also known as a monomer of a protein. Amino acids is make up of alpha carbon which then is attach to the four different groups. The four different groups are, alpha- carboxylate group, alpha- amino group, hydrogen group and side-chain group. Amino acids can make up into 20 different amino acids which is depend upon their side chain R group. Two or more amino acids can link together by peptide bond to form a protein through a process named, condensation. Proteins are polymers of an alpha-amino acid. From that, we know there is a relationship between structure of protein and its function. Therefore if we can predict a protein structure from amino acid sequence, this structural information provides very useful information

Missing part of amino acids will cause a protein to become not functioning. A disease known as sickle cell anaemia is an example of disorder sequence of amino acid in protein. Sickle cell anaemia differs from normal haemoglobin by a single amino acid residue, which a valine residue has replaced a glutamic residue. Sickle cell anaemia is a human genetic disease. Sickle cell anaemia are unable to pass through the small capillaries of the circulatory system, and circulation is hindered. This results in damage to many organs, especially bone and kidney, and also leads to death at an early age.

Hey THERE!!!

Assalammualaikum w.b.t

Here there is, my second blog that was born in a few minutes past...hehe. This is my first time trying to write in english although our PPSMI has been abolished by our goverment. I'm now wonder how my rest of my friends and I will face our future brilliant student. Learning 99% subject science in english for the 5 or 4 years and then translate it in 'bahasa' when teaching...and don't be impatient to wait for us to translate some term in english to 'bahasa'...because the first word that we are surely to say is "aaa...what we call that in bahasa?"..."what is?"..."alah yg itu"...apa ke namanya?". Haha...

aaa...bbb...ccc...

Opps!!!...sorry for diverted from our topic

Actually the purpose i'm created this blog is for us to share something about science especially biology. I'm sure that all of you will interest to know about some science facts that happen around us and of course we also can share our thought.

I think thats all from me...got to rest my eyes for a few minutes (headache + stomachache@lapar...hehe)

Got to see you soon...of course if you open and read my entry on this blog ^_^

Library UPSI
16.01 P.M