Proteins
If a Cell is a city
If a Cell is a city
Then the Organelles are the factories
Then the Organelles are the factories
Then what are the people?
Then what are the people?
. . . Proteins
. . . Proteins
Proteins Do Things!!
Proteins Do Things!!
The cell is made up mostly of water
The cell is made up mostly of water
The rest of the cell is Biological Molecules
The rest of the cell is Biological Molecules
- Lipids (Fat) - these make up all of the membranes and some stored energy
- Carbohydrates - simple and complex - a source of energy
- Proteins - these do things!!
Proteins can be structural
Proteins can be structural
- the cytoskeleton is a protein
Proteins can be structural and functional
Proteins can be structural and functional
- The myosin and actin that make up muscle fibers are protein. Like muscles themselves they provide both the structure of the muscle and its function
Proteins can be functional
Proteins can be functional
- motor proteins walking around in a cell.
- RNA polymerase - making RNA from DNA.
- Ribosomes - making proteins by assembling amino acids in the order directed by the RNA
Proteins can be messengers
Proteins can be messengers
- like insulin
The function of proteins is determined by their structure - change their structure and you change their function - compare a motor protein to a ribosome
The function of proteins is determined by their structure - change their structure and you change their function - compare a motor protein to a ribosome
20 Amino Acids makes 100,000 Proteins
20 Amino Acids makes 100,000 Proteins
26 Alphabet letters makes 170,000 English words
26 Alphabet letters makes 170,000 English words
The Human body has 25,000 genes - these code for 25,000 proteins - however, proteins are sometimes joined together to make other proteins so the human body actually has at least 100,000 different proteins in it.
The Human body has 25,000 genes - these code for 25,000 proteins - however, proteins are sometimes joined together to make other proteins so the human body actually has at least 100,000 different proteins in it.
However, there are only 20 types of amino acids.
However, there are only 20 types of amino acids.
So how can only 20 amino acids code for over 25,000 proteins?
So how can only 20 amino acids code for over 25,000 proteins?
That question is the same as asking, how can only 26 letters in the alphabet create over 170,000 English words?
That question is the same as asking, how can only 26 letters in the alphabet create over 170,000 English words?
Well it is the order of the letters. Likewise, it is the order of the amino acids
Well it is the order of the letters. Likewise, it is the order of the amino acids
Amino acids are joined together in one after the other, like letters in a word
Amino acids are joined together in one after the other, like letters in a word
They are joined by a peptide bond to create a chain of amino acids
They are joined by a peptide bond to create a chain of amino acids
This chain of amino acids is called a polypeptide chain
This chain of amino acids is called a polypeptide chain
This polypeptide chain then folds up - much like when you take a chain and place it on your table
This polypeptide chain then folds up - much like when you take a chain and place it on your table
The shape it folds up into is determined by the shape of the amino acids that it is made up of
The shape it folds up into is determined by the shape of the amino acids that it is made up of
Those 26 alphabet letters have different shapes - this is how we can read them
Those 26 alphabet letters have different shapes - this is how we can read them
Those 20 amino acids have different shapes - this is how they determine structure and function
Those 20 amino acids have different shapes - this is how they determine structure and function
Amino Acid sequence determines Protein Shape
Amino Acid sequence determines Protein Shape
Protein Shape determines Protein Function
Protein Shape determines Protein Function
My Lego truck next to my computer has both an A model and a B model - both models use all of the pieces of Lego.
My Lego truck next to my computer has both an A model and a B model - both models use all of the pieces of Lego.
Their order of assembly changes the shape of the structure and thus the function of the structure
Their order of assembly changes the shape of the structure and thus the function of the structure
These are built using 2 different Instruction sheets
These are built using 2 different Instruction sheets
These are built from different Genes
These are built from different Genes
Using the same amino acids
Using the same amino acids
The Lego blocks that a protein is made out of is called amino acids
The Lego blocks that a protein is made out of is called amino acids
There are 20 amino acids
There are 20 amino acids
Plants can make all 20 amino acids, using the glucose that they get from photosynthesis and the Nitrogen they get from nitrogen fixing bacteria in their roots
Plants can make all 20 amino acids, using the glucose that they get from photosynthesis and the Nitrogen they get from nitrogen fixing bacteria in their roots
Humans have to eat most of the amino acids - those that we can make, we can only make by altering other amino acids
Humans have to eat most of the amino acids - those that we can make, we can only make by altering other amino acids
The sequence of amino acids in the chain determines the shape the chain will fold into. The shape the chain folds into determines the function of the protein.
The sequence of amino acids in the chain determines the shape the chain will fold into. The shape the chain folds into determines the function of the protein.
The instruction for the sequence of amino acids is kept in a Gene
The instruction for the sequence of amino acids is kept in a Gene
Each Gene codes for a different protein - Humans have 25,000 Genes
Each Gene codes for a different protein - Humans have 25,000 Genes
The Genes are stored on Chromosomes - Humans have 23 Pairs of chromosomes
The Genes are stored on Chromosomes - Humans have 23 Pairs of chromosomes
We have Pairs of chromosomes because we have pairs of parents
We have Pairs of chromosomes because we have pairs of parents
This also means we have pairs of genes - one copy from mum, one from dad
This also means we have pairs of genes - one copy from mum, one from dad
These pairs of genes are called alleles
These pairs of genes are called alleles
There can be small differences in the alleles resulting in small changes to the protein
There can be small differences in the alleles resulting in small changes to the protein
Similarly, a different allele of the A model could have no stickers or be missing a piece
Similarly, a different allele of the A model could have no stickers or be missing a piece
Gene codes for a protein
Gene codes for a protein
Gene codes for a sequence of amino acids
Gene codes for a sequence of amino acids
A sequence of amino acids forms a chain, a polypeptide chain
A sequence of amino acids forms a chain, a polypeptide chain
A polypeptide chain folds up into a protein
A polypeptide chain folds up into a protein
The sequence of amino acids determines the shape that the chain will fold up into
The sequence of amino acids determines the shape that the chain will fold up into
The shape determines function
The shape determines function
Thus, a Gene codes for a protein
Thus, a Gene codes for a protein
Below is a YouTube clip made by past students, also above is a screenshot of their website
Central Idea
Central Idea
Amino Acid sequence determines Polypeptide Chain folding , which determines Protein Shape, which determines Protein Function
Amino Acid sequence determines Polypeptide Chain folding , which determines Protein Shape, which determines Protein Function
