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!

Okay, so now that you know the parts, let’s look at how they all work together!