Protein Synthesis Protein Synthesis NotesNotes

RNARNA• Central DogmaCentral Dogma: How protein is made: How protein is made• DNA DNA RNA RNA Protein Protein

• DNA stands forDNA stands for• Deoxyribose nucleic acidDeoxyribose nucleic acid

• RNA stands forRNA stands for• Ribonucleic acidRibonucleic acid

RNARNA•RNA is made RNA is made

up of a single up of a single strand of strand of nucleotides, nucleotides, not 2 strands not 2 strands like DNA.like DNA.

RNARNA• TranscriptionTranscription – process by which – process by which

genetic information is copied from genetic information is copied from DNA to RNA.DNA to RNA.

• Base pairing rules is the same Base pairing rules is the same except that Uracil binds with except that Uracil binds with AdenineAdenine

• DNA: DNA: A T A C C G AA T A C C G A• mRNA: mRNA: U A U G G C UU A U G G C U

RNARNA• Structure of RNA NucleotideStructure of RNA Nucleotide: : • 1. Ribose – sugar molecule (house)1. Ribose – sugar molecule (house)• 2. Phosphate group (circle)2. Phosphate group (circle)• 3. Nitrogen bases – A, G, C and 3. Nitrogen bases – A, G, C and

Uracil (Thymine in DNA)Uracil (Thymine in DNA)• A with U, G with CA with U, G with C

RNARNA• Types of RNA and their functionsTypes of RNA and their functions• 1.1. Messenger RNA (mRNA)Messenger RNA (mRNA) – brings – brings

genetic info. from DNA to the ribosomes.genetic info. from DNA to the ribosomes.– This is how nucleus controls cells activityThis is how nucleus controls cells activity– mRNA is the instruction for making proteinmRNA is the instruction for making protein

RNARNA• 2.2. Transfer RNA (tRNA)Transfer RNA (tRNA) – – carries amino carries amino

acids to the mRNA and Ribosome.acids to the mRNA and Ribosome.• Anticodon on the tRNA bonds to the Anticodon on the tRNA bonds to the

mRNAmRNA• Anticodon UUU would bond with mRNA Anticodon UUU would bond with mRNA

AAAAAA• tRNA are specific to 1 amino acidtRNA are specific to 1 amino acid

RNARNA• 3.3. Ribosomal RNA Ribosomal RNA

(rRNA)(rRNA)• makes up the makes up the

ribosomes (where ribosomes (where proteins are made)proteins are made)

• This is what reads the This is what reads the mRNA and where amino mRNA and where amino acids are assembled to acids are assembled to create a protein.create a protein.

RNARNA• mRNA then leaves mRNA then leaves

nucleus and nucleus and travels to a travels to a ribosome in the ribosome in the cytoplasm where it cytoplasm where it is read to is read to synthesize a new synthesize a new protein.protein.

Protein SynthesisProtein Synthesis• Protein SynthesisProtein Synthesis – production of – production of

proteins proteins

• Protein Structure:Protein Structure:• Made up of amino acids arranged in Made up of amino acids arranged in

a specific sequence.a specific sequence.• There are only 20 different amino There are only 20 different amino

acidsacids

Protein SynthesisProtein Synthesis• Protein SynthesisProtein Synthesis – production of – production of

proteins proteins

• Protein Structure:Protein Structure:• Made up of amino acids arranged in a Made up of amino acids arranged in a

specific sequence.specific sequence.• 20 different amino acids20 different amino acids• What type of molecule is a protein?What type of molecule is a protein?• Protein (Polymer), amino acids (monomer)Protein (Polymer), amino acids (monomer)

RNA SynthesisRNA Synthesis• CodonCodon – combination of 3 mRNA – combination of 3 mRNA

nucleotides.nucleotides.– Ex. AUG, GCA, CUC, or CACEx. AUG, GCA, CUC, or CAC

• Each codon codes for a specific Each codon codes for a specific amino acid.amino acid.

• mRNA: AUGUCACCAUUGmRNA: AUGUCACCAUUG

Amino Acid CodonsAmino Acid Codons• Table 10.1, several codons code for Table 10.1, several codons code for

each amino acideach amino acid• Start CodonStart Codon

• Stop CodonStop Codon

Find AA for: AUG CCU UAC Find AA for: AUG CCU UAC UGAUGA

tRNAtRNA• TranslationTranslation – process – process

of reading mRNA and of reading mRNA and assembling amino acids assembling amino acids in the correct order to in the correct order to make a proteinmake a protein

• What nucleotides What nucleotides would an AA have if the would an AA have if the anticodon was AGU.anticodon was AGU.

• Compliment would be Compliment would be UCA.UCA.

Protein SynthesisProtein Synthesis

Protein SynthesisProtein Synthesis• The ribosome will keep adding new The ribosome will keep adding new

AA until the _______ codes for a stop AA until the _______ codes for a stop codon.codon.

• What would be anti-codon for a stop What would be anti-codon for a stop codon.codon.

Different ProteinsDifferent Proteins• If all proteins are made from the same AA, then how are If all proteins are made from the same AA, then how are

there many different types of proteins?there many different types of proteins?

• The order of AA and how its folded determines what type The order of AA and how its folded determines what type of protein is made.of protein is made.

• What determines the order in which AA are placed in a What determines the order in which AA are placed in a peptide chain?peptide chain?

• The mRNA determines the order of AA, and since the The mRNA determines the order of AA, and since the mRNA is synthesized from DNA, the DNA determines what mRNA is synthesized from DNA, the DNA determines what protein is needed.protein is needed.

• All animals make Hemoglobin, but they make it differently. All animals make Hemoglobin, but they make it differently. If 2 animals made hemoglobin the same way what does If 2 animals made hemoglobin the same way what does that tell you about those 2 animals?that tell you about those 2 animals?

• They are closely related.They are closely related.

What make proteins What make proteins differentdifferent• 1. Sequence of amino acids1. Sequence of amino acids

• 2. How the protein is folded2. How the protein is folded• - every protein is folded differently - every protein is folded differently

to fit its purpose.to fit its purpose.