RNA and Protein Synthesis

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RNA and Protein Synthesis
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Write these terms in your journal

• Ribosome makes proteins
• RNA polymerase enzyme that puts together RNA
• Promoter the gene on DNA to which RNA polymerase
  binds and transcription begins
• Amino acid monomers of proteins
• Polypeptide protein
• Genes sections of DNA that code for something

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What is RNA?

• RNA Ribonucleic Acid
• Usually single-stranded
• Monomers are nucleotides (like DNA)
• Contains base, ribose (sugar), and one phosphate
• Bases A, U, C, G ( U Uracil )

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3 Types of RNA

• rRNA ribosomal RNAmakes up ribosome
• Makes the proteins and works with tRNA
• mRNA messenger RNAin the nucleus
• The messenger from DNA to rest of the cell
• tRNA transfer RNAin the cytoplasm
• Transfers amino acids to the ribosome to make
  proteins

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Protein Synthesis

• Making proteins
• 2 main steps
• Transcription written in same language. DNA
  (nucleic acid) to mRNA (nucleic acid)
• Translationput in a different language. mRNA
  (nucleic acid) to protein

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TRANSCRIPTION Contd

• OCCURS IN NUCLEUS
• (because DNA cannot leave the nucleus!)
• RNA Bonding Rules
• (A) Adenine (U) Uracil
• (G) Guanine (C) Cytosine

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TRANSCRIPTION Contd

• RNA polymerase binds to the promoter, then starts
  bonding nucleotides to make the RNA strand
• There is a gene on DNA that codes for RNA
  polymerase to stop

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TRANSCRIPTION
Adenine (DNA and RNA) Cystosine (DNA and
RNA) Guanine(DNA and RNA) Thymine (DNA
only) Uracil (RNA only)
RNApolymerase
DNA
RNA
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RNA SPLICING

• mRNA has to be proofread because parts of it do
  not code for anything. This process is called
  RNA splicing.
• Introns parts of the mRNA strand that are
  useless and are taken OUT of the mRNA strand
• Exons parts of mRNA that code for proteins and
  are left IN the mRNA strand

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CODONS and ANTICODONS

• Codon 3 nucleotide sequence of mRNA
• Anticodon 3 nucleotide sequence of tRNA that is
  complimentary to mRNA
• Example
• AUG-CGG (codons)
• UAC-GCC (anticodons)
• START CODON AUG

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TRANSLATION

• OCCURS IN THE CYTOPLASM ON A RIBOSOME
• translates nucleic acids to amino
• acids
• mRNA is read by ribosome
• Ribosome translates message (mRNA) to protein
• tRNA brings corresponding amino acid to ribosome
• Ribosome bonds amino acids together (peptide
  bonds)

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TRANSLATION Contd

• When the amino acid chain lengthens, this is
  called elongation.
• Translation stops when the ribosome reads a stop
  codon (UAG, UAA, or UGA)

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TRANSLATION
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TRANSLATION
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DNA BOTH RNA
Double strand Nucleotides (phosphate, sugar, base) Single strand
Base T Bases A, C, G Base U
Deoxyribose Sugar Ribose
DNA polymerase Requires enzymes to make molecules RNA polymerase
Made by replication Hydrogen and covalent bonds Made by transcription
Codes for the organism Used to make proteins
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Videos

• Replication, Transcription, and Translation
• http//www.youtube.com/watch?vTSv-Rq5C3K8feature
  related
• DNA Translation
• http//www.youtube.com/watch?NR1featureendscree
  nvTfYf_rPWUdY

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Can you identify the following in this diagram?
DNA, mRNA, tRNA, rRNA
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Can you identify the following in this diagram?
DNA, mRNA, tRNA, rRNA
Were you right?
rRNA
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Can you identify the following in this diagram?
mRNA, tRNA, rRNA, amino acids, proteins
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Can you identify the following in this diagram?
mRNA, tRNA, rRNA, amino acids, proteins
Were you right?
rRNA