RNA

1
RNA Protein Synthesis

• Sections 3-4

2
Structure of RNA

• Made of nuleotides
• Three differences between DNA RNA
• Sugar
• DNA deoxyribose sugar
• RNA ribose sugar
• RNA is single stranded
• RNA uses Uracil instead of Thymine to bond with
  Adenine

3
Types of RNA

• Three types of RNA
• mRNA
• Messenger RNA
• rRNA
• Ribosomal RNA
• tRNA
• Transfer RNA

4
Types of RNA

• Messenger RNA
• This is a copy of complimentary strand of DNA
• Eventually will code for a protein to be made

5
Types of RNA

• Ribosomal RNA
• RNA found in ribosomes (organelles in the cell)

6
Types of RNA

• Transfer RNA
• Help produce a protein from mRNA
• Brings amino acids (monomer of protein) to
  ribosome to bond them together and make a whole
  protein

7
Transcription

• Taking DNA and making an RNA copy
• Occurs in the cells nucleus
• RNA polymerase opens the DNA and adds RNA copy to
  the template
• Once this is made it is called pre-mRNA

8
RNA Editing

• Pre-mRNA is a rough draft to the final copy of
  mRNA
• Some parts of pre-mRNA are not needed to make a
  certain protein
• These unnecessary parts are called introns
• Introns get cut out of pre-mRNA
• Before leaving the nucleus, mRNA needs to get a
  cap and tail to finalize the RNA strand

9
The Genetic Code

• Proteins are made of amino acids
• There are 20 amino acids
• In order to make a protein from a strand of mRNA,
  the mRNA is read in a 3 letter sequence called
  codons

10
The Genetic Code

• Each three letter codon represents an amino acid
• DNA AGCGTGCCA
• RNA
• Codons
• Amino acids

11
(No Transcript)
12
The Genetic Code

• RNA knows when to start and stop based on the
  codons read
• There is ONE start codon AUG
• There are THREE stop codons UAA, UAG, UGA

13
Translation

• Taking mRNA and making a protein
• Occurs in the cytoplasm on a ribosome
• tRNA brings specific amino acids to ribosome
• If mRNA AUG, then tRNA UAC
• The tRNA has the anti-codon

14
Translation

• As new tRNA brings amino acids to the ribosome,
  past ones break off leaving just amino acids
  bonded to each other
• This continues until one of the three STOP codons
  is met
• Finished amino acid strand goes through protein
  folding

15
Mutations

• Changes in the DNA sequence that affect the cell
• Two types of mutations
• Gene mutation
• Chromosomal mutation

16
Gene Mutation

• Point mutation
• A change in one nucleotide in a DNA sequence
• Occur only in a single point of the DNA
• Can sometimes be a problem
• Frameshift mutation
• A change in the reading frame of DNA
• Since DNA is read in 3 letter codons, if there is
  an insertion, deletion, or large change in these
  codons the frame is changed

17
Chromosomal Mutation

• A change in the number of chrom0somes in the cell
• Four types
• Duplication
• Deletion
• Inversion
• Translocation