Question: what is mitochondrial DNA

Georgia Campbell answered on 13 Jun 2011:

Well, first it’s important to know what DNA and mitochondria are. DNA is basically a set of instructions stored in every cell in your body – they tell your body how to grow, determine what you look like, and make sure every cell does its job so that your body works properly.

Mitochondria are small organelles that are in every cell – they are like the cell’s batteries, and produce almost all of the energy our bodies need to work.

Most DNA in your body is ‘nuclear DNA’ – it’s stored as ‘chromosomes’ in a compartment of the cell called the nucleus, and stores almost all of the information to make you, and that your body needs to work properly. This is the DNA that is passed down from your Mum and Dad.

The only bit of DNA you have that is seperate from this nuclear DNA is called mitochondrial DNA. This is a small loop of DNA stored in the mitochondria, which has instructions to make some important proteins that the mitochondria need to work properly. Without this DNA, or if something is wrong with it, our bodies can’t make energy properly, and we get sick.

The illnesses that faulty mitochondrial DNA can cause depends on where the bad mitochondria are – a couple of common examples would be bad mitochondria in muscle cells, which causes muscle weakness and makes it difficult for patients to move around without help, or bad mitochondria in brain cells, which could cause learning problems or poormemory skills.

Hope that helps, thanks for your question!