RNA and PROTEIN SYNTHESIS © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

DNA holds the information (code) to make all of the proteins in a cell…….. But how is the information stored in DNA? In the sequence of the nucleotides

Protein Synthesis How many nucleotides are there? 4 How many amino acids are there? 20

HOW CAN JUST 4 BASES GIVE DIRECTIONS TO MAKE 20 AMINO ACIDS? Message is read in groups of 3 bases = _________ CODON Codons represent different amino acids UCGCACGGU UCG-CAC-GGU Serine - Histidine - Glycine

But how does the information in the DNA get from the nucleus to the ribosomes where proteins are made? RNA Ribonucleic Acid

MASTER PLAN DNA stays safe in nucleus TRANSCRIPTION (DNA→ RNA) takes place in nucleus TRANSLATION (RNA→ proteins) takes place on ribosomes in cytoplasm “Blueprints” of master plan are carried to building site

RNA Uses information from DNA to make proteins Is a polymer similar to DNA

RNA- the Other Nucleic Acid NUCLEOTIDES Also made of ___________ Sugar is _______ instead of deoxyribose. RNA is _________ stranded Contains _________ instead of thymine. RIBOSE SINGLE URACIL http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg

RNA Bases

3 Types of RNA Messenger RNA (mRNA) Carries genetic message from DNA to ribosomes Protects DNA More copies at the same time Easier to move

3 Types of RNA Transfer RNA (tRNA) Ribosomal RNA (rRNA) carries the amino acids to the ribosome Ribosomal RNA (rRNA) Makes the ribosomes along with proteins

3 KINDS OF RNA HELP WITH INFO TRANSFER FOR PROTEIN SYNTHESIS RIBOSOMAL _________________RNA (rRNA) Combines with proteins to form ribosomes _________________RNA (tRNA) Matches m-RNA codon to add correct amino acids during protein synthesis _________________RNA (mRNA) carries code from DNA to ribosomes TRANSFER MESSENGER rRNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved mRNA image from http://wps.prenhall.com/wps/media/tmp/labeling/1140654_dyn.gif

Transcription Process of making RNA from DNA 3 Steps DNA unwinds Nucleotides are added (U instead of T) mRNA leave the nucleus

DNA CTA-GAG-CAA-GTC-ACT What is the RNA Strand? DNA CTA-GAG-CAA-GTC-ACT

DNA CTA-GAG-CAA-GTC-ACT What is the RNA Strand? DNA CTA-GAG-CAA-GTC-ACT mRNA GAU-CUC-GUU-CAG-UGA

DNA TGC-AGT-AGG-TAC-ACT What is the RNA Strand? DNA TGC-AGT-AGG-TAC-ACT

DNA TGC-AGT-AGG-TAC-ACT What is the RNA Strand? DNA TGC-AGT-AGG-TAC-ACT mRNA ACG-UCA-UCC-AUG-UGA

Codons Combinations of nucleotides needed to code for all the amino acids 64 codons produce 20 AA

AUG 64 possible codons Some amino acids have more than one codon. Section 12-3 64 possible codons Some amino acids have more than one codon. START= _______ 3 codons for _____ AUG STOP

Translation Process of making proteins from RNA mRNA goes to the ribosome Ribosome reads mRNA in 3 base triplets called codons Codon specifies what amino acid the tRNA brings

mRNA to Proteins

EACH tRNA carries only one kind of _____________ amino acid ANTICODON ___________ on tRNA matches up with ________ on mRNA CODON EACH tRNA carries only one kind of _____________ amino acid Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

REPLICATION DNA → DNA ____________ DNA → RNA ____________ RNA→ Protein ___________ TRANSCRIPTION TRANSLATION

can be also called which functions to also called which functions to also called which functions to from to to make up

amino acids to ribosome RNA can be Messenger RNA Ribosomal RNA Transfer RNA also called which functions to also called which combines with also called which brings tRNA amino acids to ribosome mRNA Carry instructions rRNA proteins from to to make up DNA Ribosome Ribosomes

Make a Protein!

Codons AUG = start codon (methionine) UAA, UAG, UGA = stop Has to be read in the correct direction and started in the correct place