RNA and PROTEIN SYNTHESIS

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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?

UCGCACGGUUCG-CAC-GGU

CODON

Codons represent different amino acids

Serine- Histidine- Glycine

Message is read in groups of 3 bases = _________

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

RNARibonucleic Acid

MASTER PLAN DNA stays safe in nucleus

“Blueprints” of master plan are carried to building site

TRANSCRIPTION (DNA→ RNA)takes place in nucleus

TRANSLATION (RNA→ proteins)takes place on ribosomes in cytoplasm

RNA• Uses information from DNA to make proteins

• Is a polymer similar to DNA

RNA- the Other Nucleic Acid

Also made of ___________

Sugar is _______ insteadof deoxyribose.

RNA is _________ stranded

Contains _________ instead of thymine.

NUCLEOTIDES

RIBOSE

SINGLE

URACIL

http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg

RNA Bases

3 Types of RNA

1.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

2.Transfer RNA (tRNA)– carries the amino acids

to the ribosome

3.Ribosomal RNA (rRNA)– Makes the ribosomes

along with proteins

3 KINDS OF RNA HELP WITH INFO TRANSFER FOR PROTEIN SYNTHESIS

_________________RNA (rRNA)Combines with proteins to form

ribosomes

_________________RNA (tRNA)Matches m-RNA codon to add correctamino acids during protein synthesis

_________________RNA (mRNA)carries code from DNA to ribosomes

rRNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reservedmRNA image from http://wps.prenhall.com/wps/media/tmp/labeling/1140654_dyn.gif

RIBOSOMAL

TRANSFER

MESSENGER

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

What is the RNA Strand?

DNA CTA-GAG-CAA-GTC-ACT

What is the RNA Strand?

DNA CTA-GAG-CAA-GTC-ACTmRNA GAU-CUC-GUU-CAG-UGA

What is the RNA Strand?

DNA TGC-AGT-AGG-TAC-ACT

What is the RNA Strand?

DNA TGC-AGT-AGG-TAC-ACTmRNA ACG-UCA-UCC-AUG-UGA

Codons Combinations

of nucleotides needed to code for all the amino acids

64 codons produce 20 AA

Section 12-3

64 possible codons

Some amino acidshave more than onecodon.

START= _______

3 codons for _____

AUG

STOP

TranslationProcess 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

___________ on tRNAmatches up with________ on mRNA

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ANTICODON

CODON

EACH tRNA carries only one kind of _____________amino acid

DNA → DNA ____________

DNA → RNA ____________

RNA→ Protein ___________

REPLICATION

TRANSCRIPTION

TRANSLATION

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can be

RNA

Messenger RNA Ribosomal RNA Transfer RNA

mRNA Carry instructions rRNA proteins tRNA amino acids toribosome

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