Video 5mS2ls 5mS2ls

RNA STRUCTURE DNA responsible for information to make proteins RNA is responsible for making proteins using DNA’s genetic information Nucleotide chain made of ◦ Phosphate group ◦ Sugar – ribose ◦ Nitrogenous bases

RNA vs. DNA DNA Double stranded Deoxyribose sugar Bases: C,G A,T RNA Single stranded Ribose sugar Bases: C,G,A,U Both contain a sugar, phosphate, and base.

TYPES OF RNA mRNA – 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 RNA Bound to one amino acid on one end anticodon on the other end complements mRNA codon If mRNA sequence = UCG tRNA sequence = AGC

REVIEW List one way in RNA and DNA are similar List one way in RNA and DNA are different List the 3 types of RNA

Transcription Happens in nucleus of the cell The information in DNA is copied into Mrna RNA 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

TRANSLATION After 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 TRANSLATION mRNA 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 RNA Bound 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 Proteins Proteins differ from one another in the number and sequence of amino acids Proteins can be 50-3,000 amino acids in length Proteins are part of almost all cell functions ◦ AB’s ◦ Muscles ◦ Enzymes ◦ Hormones (insulin) ◦ Structural ( collagen, keratin) ◦ Storage ◦ Transport ( hemoglobin)