Protein Synthesis Study Guide

Key Concepts:
There are three major differences between DNA and RNA: 1) RNA contains the sugar ribose and DNA contains the sugar deoxyribose (w/o that extra oxygen)  2) RNA is usually single stranded instead of double stranded  3) RNA contains the nitrogen base �U� or uracil instead of �T� or thymine.

During transcription, the DNA code is transferred to messenger RNA, which carries the code out of the nucleus into the cytoplasm.

During translation, mRNA binds to the ribosomes.  Amino acids in the cytoplasm are picked up by transfer RNA and are carried to the mRNA.  The anticodons in tRNA attach to the proper codons in mRNA.  Thus the mRNA acts as a pattern for protein synthesis.  In this way, amino acids are brought together in the correct sequence to form a protein molecule.

Key Words:
Genetic code                             RNA                                  uracil
Transcription                             translation                          mRNA
Codon                                       tRNA                                 anticodon
Gene mutation                            base-pair substitution            insertions/deletions
Ionizing radiation                        nonionizing radiation              golgi bodies
ER                                            Proteins                               Enzymes
Frameshift mutation


Practice Problem:
If DNA read: 5� ATG CCG AAT TAG 3�
                   3� TAG GGC TTA ATC 5�
What would the mRNA look like?

How many codons are there?  Anticodons?

What would the first anticodon be?

What polypeptide chain would you produce?
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