The titration curves help in identifying the existence of different ionic groups present in the amino acids. In the case of neutral and basic amino acids, the number of dissociating groups is usually one and in acidic amino acids, the number of dissociating groups are usually two.
Gums are heteropolysaccharide substances made up of two or more kinds of monosaccharide units.
Fevicol is a branded synthetic product with excellent adhesive properties. It is made up of polyvinyl acetate (PVAc) glue, not a polysaccharide. There are several variations available.
The structure of the amino acid alanine:
A macromolecule is a very large molecule of relatively high molecular weight (of more than one thousand daltons) which is created by polymerization of smaller subunits, called monomers. Example: Proteins, nucleic acids, carbohydrates. Large lipids molecules are though non-polymeric, but they come under the category of macromolecules.
Cellulose is a complex carbohydrate that consists of 3,000 or more glucose units. It forms the basic structural component of plant cell walls. Cellulose comprises about 33 percent of all vegetable matter (90 percent of cotton and 50 percent of wood are cellulose) and is the most abundant of all naturally occurring organic compounds. Cellulose is found in the cell walls of secondary xylem and it is the ultimate source of production of paper. Paper is nothing but 90% secondary xylem or wood. The remaining 10% comes from the fibres of rags, straw, grass or old newspapers. According to a report, each person in the United States uses about 749 pounds of paper every year and almost 4 billion trees are cut down each year for the production of paper. The world uses 400 percent more paper now than it did 40 years ago. Used paper and paper products make up the largest portion of our trash - about 40 percent. This is indeed a huge loss of vegetation.
Yes, we can attempt building models of biomolecules using commercially available atomic models (Ball and Stick model).
Ball and Stick models are made to represent the three-dimensional structure of a chemical compound showing the position of atoms and the bonds in the 3-D space. The round balls of different colours are used to represent various atoms with sticks as bonds between these atoms. The angle and the distance between the atoms in the model are proportional to the actual molecule/compound.
Structure of cysteine
The main protein in dairy milk is caseins which contains all the essential amino acids. Caseins are composed of several similar proteins which form a multi-molecular, granular structure called a casein micelle. The casein micelle also contains water and salts. The individual casein molecules are not very soluble in the aqueous environment of milk however the casein micelle granules are maintained as a colloidal suspension in milk. Bacteria found in the milk or when added externally, ferment the sugar lactose into lactic acid. This fermentation results in the acidic environment causing the micellar structure to break and the casein comes out of solution or coagulates. The resulting gelatinous material with creamy texture is known as yoghurt or curd.
Proteins are heteropolymers containing strings of amino acids. There are 20 different amino acids. The sequence of amino acids in the protein which conveys the positional information of each amino acid is known as primary structure of the protein. This sequence of amino acid is very important for the protein as it will determine the final structure as well as function of the protein. Any deviation in the sequence of amino acids in the primary structure results in the malfunctioning of the protein. If we have a method to determine the entire amino acid sequence in the primary structure of the protein, we can connect the information to the purity or homogeneity of the protein. However, just the information about the two amino acids sitting at two ends of a protein will not tell about the purity as we will not know the composition of amino acids in the middle of the protein chain.
The tertiary structure of a protein is the actual shape of the protein molecule. It describes the structure of the complex and irregular folding of the peptide chain in three dimensions. It depicts the way alpha helices and beta sheets are arranged depending upon the particular amino acids in the primary structure. These complex structures are held together by a combination of several molecular interactions (like hydrogen bond, ionic bond, covalent bond, hydrophobic interactions between R groups) that involve the R-groups of each amino acid in the primary chain. The tertiary structure of the protein is important for the biological activity of the protein.
The important properties of enzymes are:
Qualitative tests
Item |
Test |
Procedure |
Result |
Interpretation |
Fruit Juice |
Biuret Test |
Add Biuret’s reagent to Fruit Juice |
Colour changes from light blue to purple |
Protein is present |
Grease or solubility Test
|
Put a drop of fruit juice on unglazed brown paper bag |
No translucent spot |
No oil or fat is present |
|
Ninhydrin Test |
Boil Ninhydrin solution with fruit juice |
Colourless solution changes to Blue |
Amino acids are present |
|
Saliva |
Biuret Test |
Add Biuret’s reagent to saliva |
Colour changes from light blue to purple |
Protein is present |
Grease or solubility Test |
Put a drop of saliva on an unglazed brown paper bag |
No translucent spot |
No oil or fat is present |
|
Ninhydrin Test |
Boil Ninhydrinsolution with saliva |
Colourless solution changes to Blue |
Amino acids are present |
|
Sweat |
Biuret Test |
Add Biuret’s reagent to sweat |
No change in colour |
No proteins are present |
Grease or solubility Test |
Put a drop of sweat on an unglazed brown paper bag |
Translucent spot appears |
Fats or oils present |
|
Ninhydrin Test |
Boil Ninhydrin solution with sweat |
Solution remains colourless |
No amino acids are present |
|
Urine |
Biuret Test |
Add Biuret’s reagent to urine |
Colour changes from light blue to purple |
Protein is present |
Grease or solubility Test |
Put a drop of urine on an unglazed brown paper bag |
No translucent spot |
No oil or fat is present |
|
Ninhydrin Test |
Boil Ninhydrin solution with urine |
Colourless solution changes to Blue |
Amino acids are present |
A triglyceride is an ester derived from condensation reaction of one glycerol molecule and three fatty acids. The glycerol is an alcohol with three hydroxyl (OH-) groups. Each fatty acid has carboxyl group (COOH-). In the triglyceride molecule, hydroxyl groups of the glycerol join the carboxyl groups of the fatty acid to form the ester bond. They are also referred to as neutral fats because unlike their component parts, they lack polar groups that can hydrogen bond with water. The hydrocarbon chain of the fatty acid in a triglyceride can be saturated or unsaturated depending upon the presence or absence of double bonds between carbon atoms. Triglyceride like butter which is solid at room temperature contains saturated fatty acid whereas oil contains unsaturated fatty acids and thus remains in liquid state at all temperatures.
List of proteins used as therapeutic agents:
Protein |
Therapeutic Role |
Thrombin and fibrinogen |
Blood clotting |
Insulin |
Maintaining blood glucose level in the body |
Renin |
Osmoregulation |
Trypsin |
Enzyme |
Antibody |
Treatment of auto-immune diseases and cancer |
Tissue Plasminogen Activator |
Thrombolytic agent |
Factor VIII |
Treatment of Haemophilia A |
Live and inactivated viral and bacterial proteins |
Vaccination |
Human interferons |
To fight against viral infections |
DNase I |
For treatment of Cystic Fibrosis |
Human growth hormone |
For inducting growth |
Other applications of Proteins:
Structures of 10 interesting small molecular weight biomolecules are:
Industries manufacturing small Biomolecules are:
Biomolecule |
Manufacturing Industries |
Glucose |
M/S.Vinayak Ingredients (India) Pvt ltd. |
Glycine |
Triveni Aromatics And Perfumery Private Limited, Vapi |
Glycerol |
P & G Chemicals (USA), The Tata Oil Mills Co. Ltd (India) |
Research laboratories, educational institutes and other industries use biomolecules as precursors for making other products.
Glycosidic bond: A glycosidic bond is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. Water molecule is released during the formation of glycosidic bond.
Peptide bond: The covalent bond between two neighbouring amino acids in a protein molecule, formed due to a condensation reaction between the carboxyl group of one and the amino group of another is known as peptide bond.
Phospho-diester bond: The covalent diester bond between phosphoric acid and two sugar molecules linking two nucleotides together to form the backbone of DNA and RNA is known as a phosphor-diester bond. It exists between the phosphate of one nucleotide and the sugar 3' carbon of the next nucleotide.
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