2. DNA StructureDNA Structure  DNA is composed of a chain of nucleotides.

3. DNA StructureDNA Structure  There are 4 different DNA nucleotides

5. DNA ReplicationDNA Replication  Replication = identical new strand  Occurs for cell division –mitosis or meiosis.  Replication Steps: 1. Helicase Enzyme unzips DNA molecule1. Helicase Enzyme unzips DNA molecule 2. Free nucleotides combine with complementary base pairs 3. Backbone forms by nucleotides bonding3. Backbone forms by nucleotides bonding

8. Protein SynthesisProtein Synthesis  Protein Synthesis has 2 steps: 1. In nucleus:1. In nucleus: ○ TRANSCRIPTION = forming RNA strands 2. In a ribosome:2. In a ribosome: ○ TRANSLATION = coding for amino acid chains or proteins

9. Transcription 3 Types of RNA:3 Types of RNA: Ribosomal RNA – rRNA: makes up the ribosomes Ribosomal RNA – rRNA: makes up the ribosomes Transfer RNA – tRNA: bring Amino Acids to ribosome Transfer RNA – tRNA: bring Amino Acids to ribosome Messenger RNA – mRNA: transfers gene code from DNA in nucleus to ribosome Messenger RNA – mRNA: transfers gene code from DNA in nucleus to ribosome ○ Carries the correct amino acid sequence to make proteins

10. Transcription  How RNA is different from DNA: 1. RNA is a single stranded1. RNA is a single stranded 2. RNA has ribose sugar instead of Deoxyribose sugar 3. RNA contains Uracil instead of Thymine3. RNA contains Uracil instead of Thymine 4. RNA can leave the nucleus4. RNA can leave the nucleus

12. Transcription  Process of making mRNA which is the replicating of a gene  Each mRNA is made from a series of DNA nucleotides which code for one Gene (trait). Only one side of the DNA is coded Only one side of the DNA is coded  The mRNA can then leave the nucleus to make proteins

13. Transcription Process StepsTranscription Process Steps 1. Enzyme unzips DNA at the gene location1. Enzyme unzips DNA at the gene location 2. Free RNA nucleotides match up to their complementary bases on DNA DNA:RNA:DNA:RNA: A U A U T A T A C G C G G C G C 3. RNA breaks off and leaves nucleus and the DNA strands Hydrogen bonds reconnect

15. Translation  mRNA attaches to a Ribosome in the cytoplasm.  The code is read by the ribosome in a series of 3 nucleotides (aka triplicate) – called a codon.

16. Translation – mRNA codeTranslation – mRNA code

17. Translation  Each codon codes for one amino acid 3 RNA nucleotides = 1 amino acid 3 RNA nucleotides = 1 amino acid 1 codon = 1 amino acid 1 codon = 1 amino acid  9 nucleotides =_?_Codons = _?_ Amino acids  tRNA matches up to the codons using anticodons  Each tRNA brings 1 amino acid to the mRNA  Amino Acids connect together to form proteins via polypeptide bonds

20. How Our Bodies Use ProteinsHow Our Bodies Use Proteins  Proteins control cell functions: Structure Structure Enzyme action Enzyme action Hormones Hormones