What is a protein?

Proteins are the building blocks of life and come in many different shapes and sizes. In this video, Dr Julia Horsfield, from the University of Otago, talks about the many different roles that proteins play in our bodies.

Transcript

DR JULIA HORSFIELD
Protein is a building block of life just like you hear on a Weet-Bix ad or something, and these building blocks make up all of the bits that go into building our cells and our bodies.

So proteins do very, very many different things. They can make up part of your muscle or they can make up part of how you grow your fingernails or they can have much smaller, more specified jobs inside of cells in your body. Some proteins are needed to send messages across cells from one side to the other or to the next cell maybe, and some proteins are needed to organise the bits and pieces that are inside your cell.

Inside your cell, you have protein-making factories called ribosomes – these themselves are made of proteins – and they make all the different proteins that you need for all the processes in your body. Some proteins are enzymes that need to break down energy to give you the ability to move and to think, and some proteins form part of the cell membrane or the packaging that goes round the cell that connects it with other cells around it.

And some proteins are involved in organising your DNA or your chromosomes to make sure that they are doing the right things at the right times in the cell and that, when the cell divides, that they don’t get tangled and scrambled together and also that the membrane around the DNA – so you have… the DNA’s in what is called a nucleus – and the nucleus has a membrane around it. It controls what goes in and out of the nucleus, and that is another job for proteins as well.

So you name anything that your body does, and there will be proteins involved in doing that, and they come in all different shapes and all different sizes. So some of the most famous proteins are things like haemoglobin, and haemoglobin carries your oxygen around in your body in your blood. And haemoglobin is the particular colour it is – red – because of how it carries oxygen. And oxygenated haemoglobin has a particular red colour and de-oxygenated haemoglobin is a more browny colour. So our blood is red because of the properties of haemoglobin, a protein in our bodies.

Acknowledgement:
Patrick J Lynch
Victor French, University of New Mexico, Valencia Campus, Science Department
The New Zealand Biotechnology Hub
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The C. Everett Koop Institute, Dartmouth Medical School, Dartmouth-Hitchcock Medical Center, Dartmouth College
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New Zealand Ministry of Education