RNA and Protein Synthesis
How does DNA determine our traits?
By directing the synthesis of proteins Proteins represent functional genes Molecular flow of information is: DNARNAProtein
What proteins are you familiar with?
Examples of Proteins Insulin Keratin Hemoglobin Melanin Actin
Proteins are synthesized during two cellular processes. Can you name these processes?
Protein Synthesis 1.Transcription – Genetic information is transferred from DNA to RNA 2.Translation – mRNA information is decoded to synthesize proteins
What is RNA?
A nucleic acid composed of ribose sugars, phosphates, and nitrogenous bases
How does RNA differ from DNA?
DNA RNA Double stranded Deoxyribose sugar Adenine, Cytosine, Guanine, and Thymine Nucleus only Single stranded Ribose sugar Adenine, Cytosine, Guanine and Uracil Nucleus, cytoplasm, and ribosomes
RNA Nucleotide
Who are the “players” involved in protein synthesis?
The “Players” 1.mRNA 2.tRNA 3.rRNA 4.amino acids 5.ribosomes
mRNA (messenger) linear RNA that transfers genetic information from DNA to ribosomes
tRNA (transfer) RNA (~80 nucleotides in length) twisted in hairpin shape supplies the amino acids to ribosomes for translation
rRNA (ribosomal) globular RNA that composes ribosomes, forms the peptide bond between amino acids during protein synthesis
Amino Acids monomers of proteins linked together to form proteins during translation
Ribosomes site of translation (second step of protein synthesis)
Gene Structure
Promoter Coding Region Termination Signal A
Steps of Transcription A
RNA Splicing (editing of mRNA) A
Transcription Review Transcription Review (DNA to mRNA) A
mRNA codons Codon – sequence of three nucleotides on mRNA
The Genetic Code
Translation (mRNA to Protein) Begins at the “start” codon - AUG
Codon/Anti-Codon Relationship
Translation (mRNA to Protein) Translation continues until a “stop” codon is reached – UAA, UGA, UAG A
Translation Review Translation Review (mRNA to Protein) A