Life

How to cell yourself | Jack Challoner

Jack Challoner on the building blocks of life

You are as beautiful as you are complex. I don’t know you, of course, but I do know that your body is a society of more than 30 trillion cells – all of them working together in an unimaginably complicated symphony of interdependence and diversity. And in that symphony, that complex society of cells, lies beauty.

Every one of your cells is alive but each one depends on all the others: no human cell can survive on its own. There are, of course, single cells in the world that are independent – that can survive alone. In fact, these cellular singletons (most of them are bacteria or the little known but just as numerous ‘archaea’) far outnumber us multicellular ones. Interestingly, bacteria and archaea even outnumber human cells in your own body! There are about 100 trillion of them in your digestive tract alone. Most of them play crucial roles in keeping you alive, making the population of the society that is your body even more diverse.

There are a little over 200 different kinds of human cells – including several different types of blood cell, several different types of skin cell, and so on. Each cell uses compounds extracted from the food you eat as the raw materials for building proteins – and as the source of energy needed to accomplish that remarkable feat. Some of the proteins a cell produces will be used as structural materials for your body – collagen for your skin or keratin for your hair, for example. Some proteins are chemical messengers, unconsciously keeping the body under control and in balance – insulin that maintains blood sugar at an optimum level, or oxytocin that triggers labour and breastfeeding, for example. Still other proteins are enzymes, enab-ling a host of chemical reactions that keep you alive – including digestive enzymes that enable the breakdown of complex molecules in your food, and enzymes that promote the reproduction of the DNA, the molecule of inheritance. What makes one type of cell different from another is the amount and type of protein it produces.

All cells on Earth have much in common: they all carry instructions encoded into molecules of DNA; they all follow those instructions to manufacture proteins; they all have a fatty membrane; and they all have similar ways of deriving energy from energy-rich chemical compounds absorbed across that membrane. All the cells that make up you have even more in common: they all carry an identical copy of your personal genome, the entirety of your DNA.

Despite these commonalities, cells come in a huge range of different forms, so they are the source of the incredible and beautiful diversity we see in the living world. And in multicellular organisms, diversity goes hand in hand with inter-dependence. That’s what makes a beautiful society… like you.

Jack Challoner is author of The Cell: A Visual Tour of the Building Blocks of Life published by Ivy Press, £19.99

Illustration: Mitch Blunt

Support the Big Issue

For over 30 years, the Big Issue has been committed to ending poverty in the UK. In 2024, our work is needed more than ever. Find out how you can support the Big Issue today.
Vendor martin Hawes

Recommended for you

View all
'Enormous' number of privatised NHS services across the UK, mapped: 'This is bad for everyone'
Healthcare

'Enormous' number of privatised NHS services across the UK, mapped: 'This is bad for everyone'

City of Culture 2025: Zayn Malik, Dynamo, Nia Archives and more share what makes Bradford so special
City of Culture 2025

City of Culture 2025: Zayn Malik, Dynamo, Nia Archives and more share what makes Bradford so special

Britain’s renting crisis – what it means, why we got here, and what you can do about it
A person in a yellow shirt and blue glasses is thoughtfully looking at a document labeled
Sponsored post

Britain’s renting crisis – what it means, why we got here, and what you can do about it

'Fund the NHS properly': Private sector is not the answer, Wes Streeting told, amid funding row
Health

'Fund the NHS properly': Private sector is not the answer, Wes Streeting told, amid funding row

Most Popular

Read All
Renters pay their landlords' buy-to-let mortgages, so they should get a share of the profits
Renters: A mortgage lender's window advertising buy-to-let products
1.

Renters pay their landlords' buy-to-let mortgages, so they should get a share of the profits

Exclusive: Disabled people are 'set up to fail' by the DWP in target-driven disability benefits system, whistleblowers reveal
Pound coins on a piece of paper with disability living allowancve
2.

Exclusive: Disabled people are 'set up to fail' by the DWP in target-driven disability benefits system, whistleblowers reveal

Cost of living payment 2024: Where to get help now the scheme is over
next dwp cost of living payment 2023
3.

Cost of living payment 2024: Where to get help now the scheme is over

Strike dates 2023: From train drivers to NHS doctors, here are the dates to know
4.

Strike dates 2023: From train drivers to NHS doctors, here are the dates to know