1. The Genetic Code

2. The genetic code is the “language” of mRNA instructions.
The code is written using four “letters” (the bases: A, U, C, and G).
A _________ consists of three consecutive nucleotides on mRNA that specify a particular amino acid.
codon

3. Each codon specifies a __________ amino acid that is to be placed on the polypeptide chain.
Some amino acids can be specified by more than _________ codon.
particular
one

5. There is one codon _______that can either specify the amino acid methionine or serve as a “start” codon for protein synthesis.
AUG
There are ________ “stop” codons that do not code for any amino acid. These “stop” codons signify the end of a polypeptide.
three

6. Translation is the __________ of an mRNA message into a polypeptide chain (protein).
decoding
Translation takes place on ribosomes.
During translation, the cell uses information from messenger RNA to produce proteins.

7. Messenger RNA is ______________ in the nucleus, and then enters the cytoplasm where it ______________ to a ribosome.
transcribed
attaches
Translation begins when an mRNA molecule attaches to a ____________.
ribosome

8. As each codon of the mRNA molecule moves through the_____________, the proper amino acid is brought into the ribosome by tRNA.
ribosome

9. In the ribosome, the ___________ is transferred to the growing polypeptide chain.
Amino acid
Each tRNA molecule ____________ only one kind of amino acid.
In addition to an amino acid, each tRNA molecule has ______ unpaired bases.
carries
three

10. These bases, called the ___________, are complementary to one mRNA codon.
The ribosome binds new tRNA molecules and amino acids as it moves along the mRNA.
anticodon
The process __________ until the ribosome reaches a stop codon.
continues

11. The Roles of RNA and DNA
The cell uses the DNA “master plan” to prepare RNA “_________.”
The DNA stays in the ___________.
blueprint
nucleus
protein
The RNA molecules go to the ______ building sites in the cytoplasm—the ribosomes.

12. Genes and Proteins
Genes contain instructions for assembling________.
Many proteins are enzymes, which catalyze and _________ chemical reactions.
proteins
regulate

13. component template protein
Proteins are each specifically designed to build or operate a _____________ of a living cell.
The sequence of bases in DNA is used as a ______________ for mRNA.
component
template
The codons of mRNA specify the sequence of amino acids in a __________________.
protein

14. Do Questions 8-22