Xanthoproteic Test for Tyrosine and Tryptophan

Reaction of concentrated nitric acid with some substituted aromatic rings gives a yellow color (Xanthos = yellow in Greek).

Procedure

    Set up test tubes as follows: In one tube put 2 drops of tryptophan solution, in another 2 drops of unknown compound, in another 2 drops of glycine solution, and in another about 5 mg tryosine powder. Then with great care, add 1.0 mL concentrated nitric acid (HNO₃) to each test tube. Hold the tubes so that they do not point at you or anyone else.  Heat the tubes gently in a water bath until they boil. Cool the tubes slowly and add the 4% NaOH, drop by drop, until the solutions are alkaline. 

Did any color change take place before the alkali was added? What was the final color of each of the solutions?

Download Free here: Color Reactions of Amino acids

For More: See the Amino acids Video Lectures

See the Practical Video Presentation for better understanding

Principles of Gel Electrophoresis

Electrophoresis: How to Read Results

Protein Purification with Dialysis Tubing

Protein Quantification (Bradford Assay)

Bradford assay is a rapid and accurate method to determine the concentration of protein. The assay is based on the observation that the absorbance maximum for an acidic solution of Coomassie Brilliant Blue G-250 shifts from 465 nm to 595 nm when binding to protein occurs. Both hydrophobic and ionic interactions stabilize the anionic form of the dye, causing a visible color change. Within the linear range of the assay (~5-25 mcg/ml), the more protein present, the more Coomassie binds.

Bradford Assay

Experiment using Bradford Assay to determine protein concentration. Follows a specific protocol but can be used to understand how to perform a Bradford Assay.

Electrophoretic separation of Proteins

Electrophoretic separation of Proteins

How to Make an SDS-PAGE gel

Alright so here's a quick video on how to cast an SDS-PAGE gel. Although recipes can vary, the ingredients shown here are almost always used. Remember: always add TEMED last, and pour into plates immediately after!
Already know how to make a gel, but have problems with leaky gels? Check out our other video on How to Avoid a Leaky SDS-PAGE gel: See the video here

Quantitative estimation of aminoacids by Ninhydrin Method

Amino acids are known to be the building block of all proteins. Twenty different amino acids are commonly found in proteins. Amino acids comprises of a carboxyl group and an amino group bonded to the same carbon atom (the α carbon).They differ from each other in their side chains (R groups),which vary in structure, size, electric charge and solubility in water. Hence their detection, quantification and identification in any sample constitute important steps in the study of proteins.

ION-EXCHANGE CHROMATOGRAPHY

AFFINITY CHROMATOGRAPHY

It is mainly based on the biological affinity (or) biological specificity. This technique mainly requires previous knowledge of the molecule to be separated a specific ligand will only attach with a specific molecule.

Affinity Chromatography video here

See Description and Material

Index of Free Biochemistry Courses video lectures

Free Biochemistry Video Lecture from IIT, Kharagpoor

Lecture - 1 Amino Acids I

Lecture - 2 Amino Acids II

Lecture – 3 Proteins lectures I

Lecture – 4 Protein lecture II

Lecture – 5 Protein structure III

Lecture – 6 Proteins Structure IV

Lecture – 7 Enzymes - I

Lecture - 8 Enzymes II

Lecture - 9 Enzymes III

Lecture - 10 Enzyme Mechanisms I

Lecture - 11 Enzyme Mechanisms II

Lecture - 12 Kinetics of Bi substrate Enzyme

Lecture - 13 Lipids and Membranes 1

Lecture - 14 Lipids and Membranes II

Lecture - 15 Membrane Transport

Lecture - 16 Carbohydrates I

Lecture - 17 Carbohydrates II

Lecture - 18 Vitamins and Co enzymes 1

Lecture - 19 Vitamins and Co enzymes II

Lecture - 20 Nucleic Acids 1

Lecture - 21 Nucleic Acids II

Lecture - 22 Nucleic Acids III

Lecture - 23 Bio energetics 1

Lecture - 24 Bio energetics II

Lecture - 25 Metabolism I

Lecture - 26 Metabolism II

Lecture - 27 Metabolism III

Lecture - 28 Overview of the Course

Lecture - 11 Enzyme Mechanisms II

Lecture - 11 Enzyme Mechanisms II

Lecture - 10 Enzyme Mechanisms I

Lecture - 10 Enzyme Mechanisms I

List of Metabolism video lectures

When it comes to weight loss and dieting, one word that you hear often is “metabolism.” But what is a metabolism, and how does it play a role in your weight loss goals and what is its value to you? First let me give you the commonly accepted definition of what a metabolism is.

The word metabolism is derived from the Greek language. And it means “change” or “transformation”. For our purposes of body function, metabolism is the amount of energy or calories your body burns to maintain vital functions. At every moment, be it sleeping, shopping or exercising, your body is constantly burning calories. It needs fuel just as a car needs fuel to power itself. Your metabolism is the regulator and manager of your body’s fuel.

Now here’s where it really gets interesting. Your metabolism is affected by your body composition. In plain English, this means the amount of muscle you have compared to the amount of fat you have on your body. This comparison is important because your muscle tissue burns or uses up more calories to maintain itself than fat does. That being, people who have a lot of muscle on them or mostly muscle on their frame, tend to have a higher metabolism than others who have more fat. So why should this matter to you?





List of Metabolism video lecture




1.Bioenergetics 1

2.Bioenergetics II


3. Video Intermediary Metabolism

4. Metabolism I  

5. Metabolism II

 

Lecture - 28 Overview of the Course

 

 

Lecture - 24 Bioenergetics II

 

Lecture - 23 Bioenergetics 1

Lecture - 23 Bioenergetics 1

Lecture - 19 Vitamins and Coenzymes II

Lecture - 19 Vitamins and Coenzymes II

Lecture - 18 Vitamins and Coenzymes 1

Lecture - 18 Vitamins and Coenzymes 1