Protein Synthesis The formation of proteins based on information in DNA and carried out by RNA. (Gene expression) Flow of Genetic Information: DNA “unzips”  Transcription- makes RNA  Translation- makes protein

DNA Review questions What is the shape of DNA? What are the monomers? List the three parts that make up the monomers. What type of bonds holds the parts of the monomer together? What type of bonds hold the two strands of DNA together? Where is DNA found in eukaryotic cells? What is Chargaff’s rule? What is the process in which more DNA is made? What breaks the bonds between the nitrogen bases for this process to occur? When during the cell cycle does this process occur? What form is DNA found when the cell is not dividing? When it is dividing?

3 Types of RNA Messenger RNA (mRNA) Ribosomal RNA (rRNA) Transfer RNA (tRNA)

Messenger RNA (mRNA) Carries the instructions from DNA

Transfer RNA (tRNA) Transfers amino acids to the ribosome to make a protein Has 3 nucleotides on one end (anticodon) and the corresponding amino acid on the other (codon).

Ribosomal RNA (rRNA) Make up Ribosomes

Pictures of RNA mRNA tRNA rRNA

Difference between DNA & RNA Both RNA Deoxyribose Sugar Nucleic Acid Ribose Sugar Nitrogen base T Nucleotide -Phosphate group -Sugar - Nitrogen Base (A, C, G) Nitrogen base U Double helix (double strand) Genetic Info Single Strand 1 Type 3 Types (mRNA, tRNA & rRNA) Found ONLY in Nucleus Can leave the nucleus

Transcription mRNA The process by which ______ is made from part of the ______ sequence that codes for a protein (gene) Transcription is taking the original (master) blueprint DNA and making _______ in the form of RNA This RNA blueprint will be used to assemble _________ DNA copies proteins

Steps of Transcription An ______, RNA polymerase unzips the DNA molecule at the region of the gene that is being transcribed Free _____________ form base pairs with their complementary nucleotides on the DNA strand mRNA threads away and the _____ strand rejoins mRNA leaves the _______ and goes to the cytoplasm (__________) enzyme DNA - RNA A - U T - A C - G G - C RNA nucleotides DNA nucleus ribosome

A Codon is a group of 3 nucleotides in mRNA that specifies an ___________ (building blocks of protein) Think of the ______ as the drawings on the blueprint for the genetic code amino acid codon

Transcription

What would the RNA strand read if the DNA strand read: AGC TAA CCG UCG AUU GGC

Definition of Translation mRNA Use the codon of _______ to specify the sequence of amino acids to build a _____ It is time for the Blueprint (DNA-mRNA) to be read The Blueprint (______) is sent to the construction site (________) Decoding of the genetic instructions protein mRNA ribosome

Steps of Translation ______ arrives at the Ribosome tRNA __________ are complementary to the mRNA ________ tRNA picks up an __________ _____ delivers the amino acid to the ___________ Amino acids are assembled into polypeptide chains, to form ______, held together with peptide bonds mRNA Codon Anti-codon mRNA tRNA A - U U - A G - C anti-codons codon amino acid tRNA ribosome proteins

When the mRNA is first transcribed, there are long sequences of ___________ that are not required for the synthesis of the protein called _____. The DNA sequences that code for the protein are known as ______. Introns are edited out (cut out) of the mRNA before it leaves the nucleus and the remaining ______ are spliced together to form the final mRNA nucleotides introns exons exons

Protein Synthesis Video

Mutations

Mutation GENETIC MUTATIONS (pp. 307-308) A mutation is a________________________. Although many mutations are harmful, some mutations are _________, and others may be very ____________ to an organism. There are two categories of mutations: A. Chromosomal Mutations A chromosomal mutation involves a change in the ______________ of the entire chromosome or a change in the total ____________ of chromosomes. Does not alter individual ________. These errors generally occur during _____________ or ____________. change in the DNA sequence silent beneficial structure number genes mitosis meiosis

Chromosomal Mutations

Gene Mutations: A gene mutation is a change in one gene on an individual chromosome. This may result in a change in only one _________ or many nucleotides making up that gene might be altered. The incidence of gene mutations is relatively low due to the action of _________ that _________ the DNA sequence after __________.There are two types of gene mutations: nucleotide enzymes proofread replication

Point Mutations – This is a change in one or just a few ___________, but the total number of nucleotides in the gene is not changed. This might have no effect, or change one amino acid. Therefore, the resulting ________ may or may not be altered. 2. Frameshift Mutations – This involves the __________ or __________ of a ____________. When a nucleotide is inserted or deleted, this shifts the reading of the remainder of the ________; therefore, the ___________ of the remainder of the mRNA is altered. This will usually result in tremendous changes in the _______________ chain and completed protein. nucleotides protein addition deletion nucleotide codons translation amino acid

Gene Mutations