Bio 101 RNA Protein Synthesis Notes

Chapter 10: RNA & Protein Synthesis
TSW investigate & understand common mechanisms of protein
synthesis.
RNA Structure
 Consists of a long chain of nucleotides
 The 3 parts of a nucleotide are…
o A. Phosphate Group
o B. Sugars
o C. Bases
DNA vs. RNA
 3 Main Differences
o Sugar in RNA is ribose instead of deoxyribose found in
DNA
o RNA is generally single-stranded while DNA is double
stranded
o RNA contains URACIL instead of Thymine
What is RNA?
 Ribonucleic Acid
 A disposable copy of a segment of DNA
 A working copy of a single gene
What does RNA do?
 RNA is responsible for the assembly of DNA into proteins
3 Types of RNA
 Messenger RNA (mRNA)

,  Ribosomal RNA (rRNA) – found inside ribosome
 Transfer RNA (tRNA)
Messenger RNA (mRNA)
 RNA molecules that carry copies of instructions for assembling
amino acids into proteins
 “Messengers” from DNA to the rest of the cell
Ribosomal RNA (rRNA)
 Proteins are assembled on ribosomes
 Ribosomes are made up several dozen proteins + rRNA
Transfer RNA (tRNA)
 Transfers each amino acid to the ribosome as specified in the
instructional coded within Messenger RNA
DNA Transcription
 DNA must be copied to the messenger RNA
 mRNA goes from nucleus to the ribosome in the cytoplasm
 mRNA complements known as codons
o only 3 nucleotides “letters” long
 Remember RNA has uracil instead of thymine
Transcription – Step 1
ACGTATCGCGTA
TGCATAGCGCAT
UGCAUAGCGCAU
Step 2: Template DNA is matched up with Complementary mRNA
sequences
Step 3: mRNA leaves nucleus and goes to ribosomes
Protein Translation


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