Protein Synthesis From Codes/genes to Proteins/machines Central Dogma- DNA  RNA  Protein It explains how genetic information flows

Can you break the code??? 

Making Proteins  Protein Synthesis  Process of making proteins  Two part process 1.Transcription 2.Translation

Remember Reading DNA?  The four chemical bases in DNA (A, T, C, G) create a code/gene  Ribosomes “read” this DNA code/gene to make proteins.  Where are ribosomes located?  Where is DNA located?

Nucleus Problem  Nucleus not permeable to DNA  DNA is a large to fit out of pore  Double stranded = wide  How do we get the code/gene to the ribosomes to make proteins?  Copy code into a smaller molecule  RNA (ribonucleic acid)

DNABOTHRNA RNA vs DNA What is the difference? Compare and contrast DNA to RNA

Two Types of Nucleic Acids Deoxyribonucleic Acid  DNA  Double Stranded  Nucleotide sugar = Deoxyribose  Bases = A, T, G, C Ribonucleic Acid  RNA  Single Stranded  Smaller  Nucleotide sugar = Ribose  Bases = A, U, G, C

The Tail of Two RNA’s  Two RNA types needed for Protein synthesis  mRNA  messenger RNA  tRNA  Transfer RNA

Step 1: Transcription  Process of making messenger RNA (mRNA) from DNA  Exactly like Replication (with one small difference)  Use base paring rules  C pair with G  G pair with C  T pairs with A BUT  A pairs with U (uracil)  Which enzyme is used to add nucleotides?? Protein synthesis

Modifications of Mrna before it can leave nucleus Add5’ cap- protects mRNA and allows it to leave nucleus/find a ribosome Poly (A) tail- They are added to: protect mRNA and allow it to leave nucleus/find a ribosome Introns (non-coding sequences between exons) are removed and exons (amino acid coding sequences) are spliced together

mRNA Function  Take gene from nucleus to ribosome  Disposable copies(often thoughsands) of VERY important information  Tells Ribosome how to build protein.

Transcription Practice (DNA to mRNA) Open DNA: A T G C C G T T A A C G A G T C T mRNA copy: U Cheat Sheet A = U T = A C = G G =C

Step 2: Translation  What does it mean to Translate something?  Change from one language to another  Biology Translation  To go from the language of DNA (A, T, C, G, and U) to the language of protein (amino acids)  Amino acids are the building blocks of proteins

Translation  Involves ribosome, mRNA and tRNA (transfer RNA)  Ribosome reads mRNA on codon (3 bases) at a time  tRNA matches with codon on mRNA  Brings amino acid with  Ribosome takes amino acid from tRNA and links it to growing protein

Translation summary  mRNA read by ribosome in groups of 3 bases called CODONS  Ex: AUG = Start making protein  Ex: UGA = Stop making protein  Codon on mRNA match Codon on tRNA  Codon tells ribosome what amino acid to attach to protein

Decoding mRNA  Humans use decoder  Codon wheel  Codon chart

Reading Codon Wheel  Using 3 base Codon  Start at center of the wheel  Find the first nitrogen base in codon  Sets what ¼ of circle you will work in  Move to the next ring of circle  Find second nitrogen base  Sets what ¼ of the remaining circle you are in  Move to the last ring  Find third nitrogen base  Arrive at your amino acid

Finding Amino acid for Codon GAG

Reading Codon Chart  Using 3 base Codon  Start at left side  Find the first nitrogen base in codon  Sets what row you are using  Move to the top of chart  Find second nitrogen base  Sets what column you are using  Find where column and row meet  This is the box you are working in  Find matching Codon in this box

Find the amino acid for the codon CGU

CYU Transcribe this DNA to mRNA Translate the mRNA to amino acids DNA TACGGCATC mRNA Amino Acid