DNA "The Blueprint of Life"

DNA and Protein Synthesis REVIEW: 1) Protein- chain of amino acids used for cell structure & function. 2) DNA- nucleic acid that holds information for making proteins. Watson & Crick - made first correct model of DNA (1953)

Structure of DNA a) Double Helix- shaped as a twisted ladder. b) Sides composed of sugars & phosphates. c) Each “step” is made of 2 nitrogen bases - bases are joined by weak hydrogen bonds. - Base Bonding - Adenine – Thymine (A-T) - Guanine – Cytosine (C-G)

Nucleotide!! STRUCTURE of DNA Nucleotide: 3 part subunit of DNA made of: 1) deoxyribose 2) phosphate 3) Nitrogen Base Nucleotide!!

DNA Replication - used during cell division(mitosis) - DNA makes an exact copy of itself Process 1) Enzymes break bonds between bases 2) DNA separates into 2 halves 3) Free nucleotides pair with correct bases 4) Nucleotides bond until 2 new DNA strands are formed. SEMI-CONSERVATIVE - half of the old strand is saved

DNA Replication SEMI-CONSERVATIVE - half of the old strand is saved

How does DNA make a protein?

DNA --> RNA --> Protein Proteins are the building blocks organisms (traits)

Transcription -  process where RNA is made from DNA Translation - process where proteins are made from RNA

How the Code Works The combination of A,T,G,C determines what traits you might have..... C A T C A T   =  purple hair T A C T A C  =  yellow hair

Think of the bases of DNA like letters. Letters form words Think of the bases of DNA like letters. Letters form words.... Words form sentences....                 *endless                combinations

Differences Between RNA & DNA DNA uses “Helpers” RNA( Ribonucleic Acid) - helps DNA complete protein synthesis Differences Between RNA & DNA RNA DNA SUGAR- Ribose Deoxyribose BASES- Uracil (no thymine) Thymine A-U, C-G A-T, C-G STRAND- Single Double

DNA vs. RNA

CREATED IN TRANSCRIPTION!!! Types of RNA 1) mRNA (messenger RNA) - carries genetic code from nucleus to ribosomes CREATED IN TRANSCRIPTION!!! 2) tRNA (transfer RNA) - brings amino acids to ribosomes to make proteins NEEDED IN TRANSLATION!!!

Protein Synthesis(making proteins) 1) Transcription - process of transferring genetic information from DNA to RNA Process a) Small section of DNA opens b) RNA nucleotides bond to correct bases of DNA c) Ribose and phosphate molecules bond forming a single mRNA strand d) mRNA strand leaves nucleus & travels to the ribosomes

mRNA carries the "message" to the ribosomes, where proteins are made.

TRANSCRIPTION

2) Translation - process where amino acids are organized into proteins Codons: - combination of 3 bases on the mRNA - each codon codes for 1 amino acid - some amino acids have more than one codon. - some codons start & stop the mRNA chain.

CODON CHART

Translation Process a) tRNA anticodons bond with codons of mRNA b) The opposite end of the tRNA has an amino acid Example mRNA codons- AAU AUC GCU tRNA anticodons- UUA UAG CGA c) linked amino acids are connected by a peptide bond d) tRNA anticodons release to retrieve another amino acid

TRANSLATION

Mutations - any changes in genetic material Types 1) Gene Mutation - mutations that involve only one gene or one base Example Point Mutations(one base): a) Substitution- when one base is replaced by another. b) Frameshift- when the entire code shifts due to one base being added or deleted.

Point Mutation

Frameshift Mutation

2) Chromosome Mutation - mutation that affects multiple bases and/or multiple genes. Example a) Deletion- loss of all/part of a chromosome b) Insertion- addition of extra gene(s) c) Inversion- location of genes are reversed d) Translocation- part of a chromosome breaks off and attaches to another chromosome.

Chromosome Mutations