GREEN CARDAMOMS/Gaurangi Maitra
WHAT CONNECTS yards of beautiful silk, glowing tresses; melt-in-the-mouth sandesh; body protecting antibodies; bio-catalytic enzymes and anti-diabetic insulin? A single word protein!
Protein means ‘of the first importance’ in Greek. When I survey the world of bio-molecules, I am more than inclined to agree with the 19th century chemists who named them.
Proteins are an integral part of the fabric of life. They build, protect, catalyse and stabilise life structures and processes. No cell can divide; no growth in living forms can take place in the absence of proteins. The very membranes that separate the living environment from the non living have proteins forming essential structural components. Inside these membranes bound compartments or cells, life supporting and generating structures work, many of which are protein based. When chemical reactions in living things create the sum total called metabolism, thousands of chemical reactions run simultaneously and with maximum efficiency, thanks to biocatalysts called enzymes, large majority of which are proteins.
Living organisms like us have our biological individuality conferred by these molecules. Whether we are allergic, have O-positive or A-negative blood groups, who we can accept an organ transfer from how we fight foreign invasions in our bodies is due to proteins. Health is protein dependant. A balanced diet must contain proteins in the correct proportion. If a blood test revels presence of abnormal levels of an enzyme like tyrosinase, the chances of having albinism is very high. The pregnancy test is based on the presence or absence of a protein hormone called human chorionic gonadotropin. Many chemical messengers within the living system are proteins as are some of the hormones.
A whole host of functions we associate with life are protein based. The protein based enzymes in the photosynthetic process help to feed the living population on planet Earth. The very movements we associate with living creatures are due to contractile proteins. So whether you wink or wrestle, play or hug, contractile proteins come into play. Vital circulation of oxygen and removal of carbondioxide within our bodies is dependent on the proper functioning of haemoglobin, an iron containing protein. Being blue blooded is far from royal, it is life threatening! It probably is due to an oxygen deficiency thanks to haemoglobin malfunction .Our bodies fight off foreign invasions thanks to special proteins called antibodies. Nail, hair, wool, hoof, feathers are all protein based products. The ability to multiply or reproduce requires DNA to duplicate, a process helped by protein based enzymes.
What forms of physical structure do these molecules have? Entire texts have been dedicated to this. As also have the lives of scientists like F Sanger, Max Perutiz and a host of others. To cut a long story short, proteins have structures to suit their function. Whatever keeps this structure intact helps them to work. Whatever does not, destroys them. Therefore they seem to define the limits within which living systems can operate.
Biotechnology which allows us to create genetically modified organisms is dependent on special protein based enzymes! The silk I began with, glorious in its texture, colour and value, is at the end of the day a protein called fibroin, unravelled from the silkworm cocoon. I end by saying if proteins work normally, life would be silk smooth and, as intricately and beautifully interwoven.
