Molecular Genetics
DNA Overview
DNA (deoxyribonucleic acid) is the basic building block of life as we know it. It resides inside of every single cell in every living thing on Earth, and it contains all the information needed for the cell to function.
Through a process called transciption and translation, DNA provides the information to synthesise proteins, which form the basis of all cell functions.
DNA can also replicate itself. When triggered, the DNA will make a complete copy of itself, and the cell will divide, forming two cells called daughter cells. This is the basis of continuing life.
Chromosomes
A chromosome is one very long DNA molecule, coiled up tightly around a chain of protiens. This is how the DNA is kept from tangling and how the information stays organized. They always come in pairs.
Humans have 46 chromosomes in every cell, or 23 pairs. The only exception is sex cells, which have 23 chromosomes.
Genetic Mutation
Sometimes, something goes wrong. A DNA strand gets replicated incorrectly, or the tRNA matches on to the wrong codon. This is when a mutation occurs. This often makes the cell that mutated die, though not always. Cancer is basically mutated cells multiplying out of control.
If there is a mutation or an error in the sex cells, the child will be often be born with some form of genetic disorder, such as Down Syndrome, where the child has an extra chromosome.
Mutations happen to all forms of life. Occasionally, mutations benefit the organism, but more often they make it harder for them to survive.
