Nucleotides (sugar, phosphate, base) Protein Synthesis 1) Give the complementary DNA sequence for: A T G C C C T A T A A G 2) What is DNA made up of? 3) Think back to our unit on MACROMOLECULES….what is the building block of a protein? T A C G G G A T A T T C Nucleotides (sugar, phosphate, base) Amino Acids

Objective SWBAT: investigate protein synthesis in order to explain how a gene is used to express a physical trait.

So…DNA makes us who we are BUT HOW???? DNA has the code to eventually make PROTEINS!!!! PROTEINS are what makes us LOOK the way we LOOK! Today’s KEY Questions: How are proteins CREATED? How is DNA related to proteins? Proteins control everything our body does! Proteins are what makes us LOOK the way we LOOK They are the expression of our body’s DNA or genes *

Let’s Review a few things… 1) What is a gene? 2) What are genes made of? 3) What are the building blocks of proteins? Part of DNA that codes for a protein DNA Amino Acids

physical traits DNA genes proteins Proteins are what create your PHYSICAL Traits.. Life in a cell is ALL about Making Proteins!! What is the relationship between the following key terms?: physical traits DNA genes proteins _____ → ______ → _________ → _________ Physical traits DNA genes proteins

PART 1: What are the MAJOR DIFFERENCES between DNA and RNA? Strand #: SINGLE-stranded DOUBLE-stranded Sugar: RIBOSE DEOXYribose 3. Bases: Cytosine, Guanine, Cytosine, Guanine Adenine, URACIL Adenine, Thymine

Remember, uracil replaces thymine in RNA … C pairs with G and A pairs with U

3 Types of RNA… Messenger RNA (mRNA) Ribosomal RNA (rRNA) Transfer RNA (tRNA) Each type has a specific ROLE in the cell!

Check for understanding! DNA or RNA?! DNA AATCGTAATGCA ______________ Why? _________________________________________ 2) CGGUGACCAUGG _____________ Because it has the base T (thymine) RNA Because it has the base U (Uracil)

DNA and RNA are needed to make proteins! Protein synthesis is the process of making proteins. More specifically, protein synthesis is: DNA sending information to RNA to make a protein A→ RNA → Protein DNA RNA Step 1 Step 2

Let’s Practice!! Complete the Venn Diagram

Process of Transcription: Step 1: TRANSCRIPTION Occurs in the _________________ ________ DNA _______ mRNA transcription nucleus DNA is transcribed into mRNA This happens inside the nucleus. DNA CAN NEVER LEAVE THE NUCLEUS! Process of Transcription: Step 1: Double stranded DNA “unzips” Step 2: RNA bases bond to the DNA strand **Remember RNA uses U NOT T 2 1 *

Transcription…. *

Check for understanding 1.What is the major end result of transcription? 2.Where does the process of transcription occur? 3.What are the complimentary strands of mRNA for the DNA template strands: G G T A T T C A A C A T T T A __ __ __ __ __ __ __ __ __ __ __ __ __ __ mRNA Nucleus C C A U A A G U U G U A A A U

In your own words… Describe the process of transcription to the class using the key words below. mRNA DNA Nucleus Single-stranded

After transcription… There is a new mRNA strand that was made from the DNA! The mRNA is ready to leave the nucleus But…where is it going???

Step 2: RNA makes PROTEINS through TRANSLATION Occurs at the __________________ mRNA protein translation ribosome At the ribosome the mRNA is translated into proteins (amino acids) through the process of TRANSLATION. RNA helpers: rRNA: makes the ribosome tRNA: brings the CORRECT amino acids to the ribosome

Process of translation mRNA leaves the nucleus and finds the ribosome A set of 3 mRNA bases is called a CODON. Each codon “codes” for a single AMINO ACID. AAG UUA CGC TUG CODONS!

What amino acids do the following codons code for? Every codon “codes” for a specific AMINO ACID (protein building block)…. What amino acids do the following codons code for? AUG: Methionine (Start)CUG:Leucine ACC: Threonine UAG:Stop You try! GUU: ____ AGU: ______CCU: ______UAU: __________ valine serine proline tyrosine

Histidine is the NEXT amino acid to be added! 3) A tRNA molecule brings in the CORRECT amino acid for each codon. 4) Eventually a chain of amino acids is created. This is a PROTEIN! Amino acid Label the following: - mRNA - tRNA - Amino Acid tRNA mRNA Histidine is the NEXT amino acid to be added!

http://www.iusd.org/uhs/cs2/i mages/Codon_Chart.gif

Important Review Points… The correct tRNA molecule will bind to the mRNA and attach an amino acid in the correct sequence The order of the amino acids determines what protein is made!!! Which comes first, TRANSCRIPTION or TRANSLATION? TRANSCRIPTION!!

Protein synthesis! TRANSCRIPTION RNA is transcribed from a DNA template. DNA RNA polymerase transcript RNA PROCESSING In eukaryotes, the RNA transcript (pre- mRNA) is spliced and modified to produce mRNA, which moves from the nucleus to the cytoplasm. Exon Poly-A RNA transcript (pre-mRNA) Intron NUCLEUS Cap FORMATION OF INITIATION COMPLEX After leaving the nucleus, mRNA attaches to the ribosome. CYTOPLASM mRNA Growing polypeptide Ribosomal subunits Aminoacyl-tRNA synthetase Amino acid tRNA AMINO ACID ACTIVATION Each amino acid attaches to its proper tRNA with the help of a specific enzyme and ATP. Activated amino acid TRANSLATION A succession of tRNAs add their amino acids to the polypeptide chain as the mRNA is moved through the ribosome one codon at a time. (When completed, the polypeptide is released from the ribosome.) Anticodon A C U G E Ribosome 1 5 3 Codon 2 3 4 5

CFU: What comes first?... Transcription or Translation? mRNA or protein? DNA or protein? DNA or mRNA? Process at the RIBOSOME or process at the NUCLEUS? Transcription mRNA DNA DNA NUCLEUS!

Complete the Questions on the bottom of your Notes Sheet!

Video clip of protein synthesis… Journey inside the cell http://www.youtube.com/watch?v=1fiJupfbSpg

Exit Ticket: answer the questions on the last page of your notes

EXIT TICKET ANSWERS What structure is shown in step I? What process is happening in step II? What is made during step II? What process is occurring is step IV What is the end product of step IV? DNA transcription mRNA translation a protein

Work with your group to complete the LAB posted at your station. Lab activity…. Work with your group to complete the LAB posted at your station. You must turn in 1 project PLUS a LAB sheet for your group!