Transcript Cooking Up Proteins

Protein Synthesis
APK: How do genes determine the traits of an
organism?
A DNA molecule is made
up of four different
nitrogen bases:
Adenine
Thymine
Guanine
Cytosine
These bases are arranged
in a specific order in a
DNA molecule. For
example: ATGACGTAC
• The order of nitrogen bases along a gene forms
a genetic code that specifies what type of
protein will be produced.
• The protein produced is what signals the body to
produce a certain type of trait in an organism.
– For example, Mendel’s pea plants either being tall or
short were the result of proteins signaling tall or short
plants.
A chromosome contains thousands of genes along
its length. The sequence of bases along a gene
forms a code that tells the cell what protein to
produce.
The DNA double helix must unwind in order for
protein synthesis to take place.
ATGACGTAC
• Codon - A group of three nitrogen bases that
makes up the code for one of the twenty
amino acids.
The three nitrogen
bases code for a
specific amino
acid. The amino
acids then link
together to form a
protein.
Cooking Up Proteins: How Cells make
Proteins
• Protein synthesis is a hard concept to
understand so perhaps comparing the parts to
a kitchen may help in understanding.
DNA Genome = recipe book
mRNA = head chef
Ribosome = pan
Amino Acids = ingredients
tRNA = assistant chef
Protein = final dish
• The DNA genome holds all of an organism’s
hereditary information.
Just like a cookbook holds all of your recipes.
• Messenger RNA (mRNA) copies the coded
message from the DNA in the nucleus and
carries the message into the cytoplasm.
Just like the Head Chef copies the recipe from
the cook book onto the chalkboard for his
assistant chefs to copy.
• Transfer RNA (tRNA) carries amino acids and
adds them to the growing protein chain.
Just like assistant chefs bring all of
the ingredients to the pan.
• The ribosome is where proteins are made.
Just like the pan is where the food is made.
• Amino acids are what link together to make
proteins.
Just like ingredients come together
to make a final dish.
• Proteins are the final product of protein
synthesis. Proteins are what signal the body to
make certain genes.
Just like the final dish (in this case – chicken) is
the final product.
Check out this great video on protein synthesis!
http://www.youtube.com/watch?v=zwibgNGe4aY
Okay, so now that you know the parts, let’s look at how
they all work together!