Video http://

www.youtube.com/watch?v=41_Ne5mS2ls

RNA STRUCTUREDNA responsible for information

to make proteinsRNA is responsible for making

proteins using DNA’s genetic information

Nucleotide chain made of◦Phosphate group◦Sugar – ribose◦Nitrogenous bases

RNA vs. DNADNA

Double strandedDeoxyribose sugar Bases: C,G A,T

RNASingle strandedRibose sugarBases: C,G,A,U

Both contain a sugar, phosphate, and base.

TYPES OF RNAmRNA – Messenger RNA

◦Synthesized from DNA and carries the instructions to make proteins

tRNA – Transfer RNA ◦ Responsible for reading mRNA and

placing correct amino acids together to form a protein

rRNA – Ribosomal RNA ◦RNA found in ribosomes

tRNA

Transfer RNABound to one

amino acid on one end

anticodon on the other end complements mRNA codon

If mRNA sequence = UCG

tRNA sequence = AGC

REVIEWList one way in RNA and DNA are

similarList one way in RNA and DNA are

differentList the 3 types of RNA

TranscriptionHappens in nucleus of the cellThe information in DNA is copied into

MrnaRNA Polymerase binds to a site on DNA

at the promoter (start location)RNA polymerase unwinds and

separates DNA and then adds the complimentary RNA bases, producing a strand of mRNA

Behind RNA polymerase the DNA strands close up and reform the helix

TRANSLATIONAfter mRNA is made it is

transported into the cytoplasm of the cell in order to be translated

Needs to be changed from language of RNA to the language of proteins(amino acids)

Each three-nucleotide sequence on RNA is called a codon and each codon corresponds to an amino acid

STEPS OF TRANSLATIONmRNA joins with a ribosome and tRNA

◦ tRNA contains anticodons which are complimentary to mRNA’s codons, and also carries the corresponding amino acid

◦ mRNA has start signal (AUG) and an end signal◦ As tRNA binds it leaves the correct amino acid

behind ◦ The next tRNA and amino acid move in and

places the second amino acid◦ Amino acids keep bonding together to form a

long chain until a stop signal is encountered.◦ When finished the newly formed polypeptide

falls off of the ribosome.

tRNA

Transfer RNABound to one

amino acid on one end

Anticodon on the other end complements mRNA codon

If mRNA sequence = UCG

tRNA sequence = AGC

Practice transcription/translation

Mleonessciencepage.wikispaces.com◦DNA Section

Click on Transcribe & Translate a Gene Zero Bio – Protein Synthesis Print screen shot when finished and turn

in with your name

Purpose of Protein Synthesis

Create ProteinsProteins differ from one another in the number

and sequence of amino acidsProteins can be 50-3,000 amino acids in lengthProteins are part of almost all cell functions

◦AB’s◦Muscles◦Enzymes◦Hormones (insulin)◦Structural ( collagen, keratin)◦Storage◦Transport ( hemoglobin)