Stated Clearly presents
What exactly is a gene?
each one of our cells contains 46 strands of DNA.
A single strand is made up of millions of particles called nucleotides.
Nucleotides come in 4 different types
which scientists have labeled
A C T and G
A gene is a special stretch of DNA:
a sequence of As Cs Ts and Gs,
that codes for something.
a gene contains information for a cell to read but what exactly does that information do?
You might have heard that there's a blue eye gene,
a freckle gene,
and possibly even in anger gene, but single genes don't literally make things like
eyeballs are freckles or
temper tantrums.
Genes make proteins.
Those proteins then interact with each other
and all sorts of other chemicals inside the body
to build things like freckles, eye pigments, and mood altering hormones.
A single strand of DNA contains thousands of genes or
unique protein recipes.
Humans have roughly twenty thousand all together.
Some genes are small,
only about three hundred letters long,
others are well over a million.
The length and sequence of a gene
determine the size and shape of the protein it builds.
The size and shape of the protein, determine the function that protein will
have inside the body.
Hemoglobin for example, is a protein structure found in red blood cells.
Its unique shape and size allowed it to capture oxygen molecules when blood flows
near the lungs,
and then release them later when blood flows near oxygen starved tissues.
Pepsin is a digestive protein.
Its unique shape allows it to break down food inside your stomach
so it can be absorbed by the body.
Keratin
is a structural protein
its unique shape and size allow it to link together with other karatin
proteins to form hard structures like fingernails, claws and beaks.
Different creatures have different genes which
is ultimately why their bodies look and function differently,
but one of the many reasons scientists believe all life on earth is related
is that the basic DNA code,
the language of As Cs Ts and Gs,
is pretty much the same for all living things.
Many creatures even share some of the same genes.
You may not be too surprised to learn that humans and chimps (which are closely related)
share about ninety six percent of their genetic code,
but what would you think that a
lowly fruit fly has in common with a beautiful swimsuit model?
surprisingly,
about half of its genes.
Because all creatures use DNA in pretty much the same way,
genetic engineers have found that they can take the gene from say
a bacteria cell,
and inserted into the DNA of an animal or plant cell.
That animal or plant cell will read the gene
and produce the bacterial protein.
Engineers have mixed and matched the genes or many different organisms
to produce many new creatures,
including corn that is toxic to insects but supposedly safe for human consumption,
tomatoes that last up to twice as long and the grocery store before going bad,
and a new form of bacteria
that produces the human protein insulin, which we then collect from these
bacteria and give to people with diabetes who need extra insulin to survive.
So just to sum things up a bit,
What exactly is it gene?
A gene is a special stretch of DNA,
not an entire strand of DNA, justice a segment,
that codes for something.
Each gene is like a unique recipe which usually tells a cell how how to make a
protein or a group of proteins.
Different creatures have different genes,
but all genes are written in the same basic DNA language
of As Cs Ts and Gs
I'm Jon Perry,
and that's Genes, Stated Clearly.