Genes & Proteins - ScienceGonnaGetYou

GENES are sections of chromosomes that cause a certain protein to be made.
Because chromosomes come in pairs, each gene has 2 pieces of information that work together to make proteins.
In our example to the right, yellow, green and blue regions all direct for different proteins.
- Notice how there are several other “striped” looking regions which code for different proteins as well.
- Each chromosome has hundreds of genes that direct the body to make different proteins.

PROTEINS are molecules that build body structures.
- Red blood cells transport oxygen via proteins called hemoglobin.
- Hair and fingernails are built with a protein called keratin.
- Sugar is transported from the blood into cells with a protein called insulin.
- The protein that gives human eye, hair and skin color is called melanin.
Each of these proteins is made by the body with the direction on one or more genes.

ALLELES are different forms of genes that create different forms of proteins which lead to variations in traits (also known as phenotypes).
- These differences aren’t actually visible by looking at the chromosomes, so it’s taken a lot of science to figure out genetics!
Because each gene has 2 spaces for information, we inherit 2 alleles for every trait.
- Alleles are often represented with letters like Z or z, but we will also represent them with shapes for a visual:)

Human hair is is bult with a protein called keratin.
The way the proteins are connected to each other result in hair types that range from straight -> wavy -> curly.

Straight hair is actually perfectly round like a spaghetti noodle. The flatter someone’s hair is, the curlier it will be!

Hair proteins are linked at the direction of the two pieces of information on the hair gene (top orange section of model)
2 different alleles can fit on the gene:
- Straight (shown as a triangle)
- Curly (shown as heart)
Notice there is no curly allele!

When straight alleles are present on both chromosomes, keratin is linked into round hairs.

When one curly and one straight allele is present, keratin is linked into oval shaped round hairs.

When only curly alleles are present on both chromosomes, keratin is linked into flat hairs.

While the models above are a great way of showing how genes determine proteins, scientists don’t carry around markers and draw shapes.

Scientists represent different alleles for a trait with letters:
- A – curly hair allele
- a – straight hair allele
GENOTYPES describe what two pieces of exist on a gene:
- AA – Curly hair
- aa – straight hair
- Aa – wavy hair
Super simple way to represent a complicated concept, eh?