1. DNA

2. What is DNA? A nucleic acid
Carries genetic information on how to make proteins
AKA the blueprint (instructions)
Located in the nucleus of a cell

3. Overall Structure of DNA
Shape is called a Double Helix-has two strands
(Looks like a twisted ladder)
The sides of the “ladder” are a phosphate-sugar backbone
The rungs of the “ladder” are nucleotides

5. Nucleotide Parts
A nucleotide from each strand connects to each other to form the rungs on the ladder
Nucleotides are made of 3 parts:
Phosphate
Deoxyribose Sugar
Base

7. Nucleotide Base-Pairing Rules
Adenine-Thymine (A-T)
Guanine-Cytosine (G-C)

10. DNA 2 meters of DNA in each cell of your body
DNA wraps around histone proteins to form chromatin
Before cell division, chromatin winds up (condenses) to form chromosomes

12. DNA Replication Process is called semi-conservative:
Each “new” molecule of DNA has one strand that is new, and one that came from the original strand

13. Replication Process Helicase unwinds the DNA & separates the strands
DNA polymerase binds to each template strand of DNA
As DNA polymerase moves along the strand, new nucleotides are added
RESULT: 2 identical DNA molecules

18. Protein Synthesis

19. DNA vs. RNA RNA Structure DNA Structure Single stranded Sugar = ribose
Bases:
Adenine
Cytosine
Guanine
Uracil
Double stranded
Sugar = deoxyribose
Bases:
Adenine
Cytosine
Guanine
Thymine

20. Base-Paring Rules in RNA

21. RNA Function-Make proteins!
Messenger RNA (mRNA)
Carries DNA message from nucleus to ribosome
Ribosomal RNA (rRNA)
Makes up part of the ribosome
Transfer RNA (tRNA)
Carries the correct amino acid to the ribosome

22. Transcription & Translation
Two steps:
Transcription: Process of copying a DNA message onto an mRNA molecule.
Translation: Process of translating the message on an mRNA into a protein.

23. Transcription
the production of an mRNA copy of a gene for use in protein synthesis
this process allows the cell to keep the DNA master copy safe within the nucleus
uses RNA polymerase to match up bases to make a copy of one gene that will code for a protein
when complete, the mRNA copy detaches, leaves the nucleus, and attaches to a ribosome in the cytoplasm

25. Translation
the process of turning the code contained in DNA into a sequence of amino acids – occurs at ribosomes
every 3 bases on the mRNA equals one codon
each codon codes for a specific amino acid
each codon on the mRNA matches up to an anticodon on a tRNA (which carries the correct amino acid)
this translation of the codons in mRNA into a sequence of amino acids is how proteins are made, and how genes are expressed

27. Central dogma
DNA
Transcription
mRNA
Translation
Protein

28. Detailed Steps: Transcription
1. the DNA unwinds at the gene that needs to be copied 2. RNA polymerase matches up RNA nucleotides to the exposed gene sequence on the DNA 3. As RNA polymerase matches the nucleotides, they join together to form a strand of mRNA 4. Once the gene is copied, the mRNA disconnects from the DNA and is edited before leaving the nucleus.

30. Detailed Steps: Translation
1. the mRNA binds to a ribosome at the start codon (AUG) 2. the tRNA with the correct anti-codon (UAC) and the amino acid Methionine (Met) joins to the start codon 3. the tRNA with the correct anticodon binds to the next codon 4. a peptide bond forms between Methionine and the amino acid attached to the second tRNA 5. as each tRNA binds to the mRNA, the amino acids are joined into a peptide chain 6. when complete, the peptide chain is modified and folded to become a functional protein 7. each tRNA reloads with the correct amino acid to be ready for the round of protein synthesis

31. Codons & Anti-Codons
Every 3 nucleotides makes up a codon, and each codon matches up with an anti-codon on a tRNA molecule that has a specific amino acid attached to the other end

32. Protein synthesis Example: DNA: TAC CGG TAA CGC mRNA: AUG GCC AUU GCG
Amino
Acid: Met Ala Ile Ala