DNA, Genes, and Proteins

Characteristics are based on the same genetic code stored in DNA

DNA (Deoxyribonucleic Acid) holds the coded information for how to make every protein a living organism might need throughout its entire life. Double Helix

Nucleotides Parts of DNA

Nucleotides The subunits of the DNA strand 2 structural versions Purine Pyrimidine Nucleotides The subunits of the DNA strand 2 structural versions Purine Pyrimidine

Bases of DNA Size and structure of the specific nucleotides cause Adenine & Thymine to always pair together Cytosine &Guanine always pair together. Bases of DNA Size and structure of the specific nucleotides cause Adenine & Thymine to always pair together Cytosine &Guanine always pair together.

Complementary Hydrogen bonds Complementary strands held together by Hydrogen bonds

DNA 5’ and 3’ ends The carbons in the deoxyribose are numbered 1’  5’ Each strand in the double helix runs opposite of the other The carbons in the deoxyribose are numbered 1’  5’ Each strand in the double helix runs opposite of the other

DNA Replication 2 steps – Unzipping DNA – Filling in space with free floating nucleotides – 2 new Daughter strands Half original and half new

Replication happens in bubbles throughout the DNA not from top to bottom

Replication: 1st step Unwind DNA – Enzymes are needed to complete the process Replication Bubble replication fork helicase

DNA Polymerase III Replication: 2nd step  Build daughter DNA strand  add new complementary bases  More enzymes needed to complete the process

energy

How it Happens

DNA is a long string of bases (A, T, G, C) Small sections of these bases that are codes for a protein are called genes 1 gene is a recipe for 1 protein

Proteins chains of amino acids The order of amino acids in the chain determines the shape of the protein The shape of the protein determines what its job is

Hemoglobin (protein that caries oxygen in your blood)

Structure Collagen Along with many other proteins it helps build musclesCollagen Or you can just inject it directly into your face

Regulation Insulin A protein that helps regulate blood sugar levels Insulin A protein that helps regulate blood sugar levels

Enzymes H 2 O 2  H 2 O + O 2 Catalase is an enzyme that breaks down hydrogen peroxide in your body Some enzymes can put stuff together like DNA Polymerase

Meet Andi… What makes him glow? ? Aequorea victoria A protein called GFP or Green Fluorescent Protein

GFP DNA Coding Sequence atgagtaaag gagaagaact tttcactgga gtggtcccag ttcttgttga attagatggc gatgttaatg ggcaaaaatt ctctgtcagt ggagagggtg aaggtgatgc aacatacgga aaacttaccc ttaattttat ttgcactact gggaagctac ctgttccatg gccaacactt gtcactactt tctcttatgg tgttcaatgc ttctcaagat acccagatca tatgaaacag catgactttt tcaagagtgc catgcccgaa ggttatgtac aggaaagaac tatattttac aaagatgacg ggaactacaa gacacgtgct gaagtcaagt ttgaaggtga tacccttgtt aatagaatcg agttaaaagg tattgatttt aaagaagatg gaaacattct tggacacaaa atggaataca actataactc acataatgta tacatcatgg gagacaaacc aaagaatggc atcaaagtta acttcaaaat tagacacaac attaaagatg gaagcgttca attagcagac cattatcaac aaaatactcc aattggcgat ggccctgtcc ttttaccaga caaccattac ctgtccacac aatctgccct ttccaaagat cccaacgaaa agagagatca catgatcctt cttgagtttg taacagctgc taggattaca catggcatgg atgaactata caaa GFP DNA Coding Sequence atgagtaaag gagaagaact tttcactgga gtggtcccag ttcttgttga attagatggc gatgttaatg ggcaaaaatt ctctgtcagt ggagagggtg aaggtgatgc aacatacgga aaacttaccc ttaattttat ttgcactact gggaagctac ctgttccatg gccaacactt gtcactactt tctcttatgg tgttcaatgc ttctcaagat acccagatca tatgaaacag catgactttt tcaagagtgc catgcccgaa ggttatgtac aggaaagaac tatattttac aaagatgacg ggaactacaa gacacgtgct gaagtcaagt ttgaaggtga tacccttgtt aatagaatcg agttaaaagg tattgatttt aaagaagatg gaaacattct tggacacaaa atggaataca actataactc acataatgta tacatcatgg gagacaaacc aaagaatggc atcaaagtta acttcaaaat tagacacaac attaaagatg gaagcgttca attagcagac cattatcaac aaaatactcc aattggcgat ggccctgtcc ttttaccaga caaccattac ctgtccacac aatctgccct ttccaaagat cccaacgaaa agagagatca catgatcctt cttgagtttg taacagctgc taggattaca catggcatgg atgaactata caaa Gene For Making GFP

Reading or “expressing” Genes Two major Steps Transcription Translation Moving from Gene to protein

Transcription (Step 1) Copying a short segment of DNA (a gene) Helps moves genetic information from inside the nucleus out to the ribosomes using a special nucleic acid called RNA Transcription (Step 1) Copying a short segment of DNA (a gene) Helps moves genetic information from inside the nucleus out to the ribosomes using a special nucleic acid called RNA

DNARNA Deoxyribose Double Stranded Adenine - ThymineAdenine - Transcription (Step 1) Transfer information from DNA onto a strand of RNA… specifically mRNA Transcription (Step 1) Transfer information from DNA onto a strand of RNA… specifically mRNA

Gene

Translation mRNA is read by ribosomes and then translated into a protein Chain of amino Acids tRNA helps bring amino acids together to form protein chain

Cracking the Code

Starting and stopping the protein sequence

Dead or Alive? Viruses and DNA Replication

What constitutes being alive?

Virus structure Piece of DNA or RNA surrounded by a protein coat called a capsid Sometimes that capsid is surrounded by a lipid bi-layer – This is to help it enter through the cell membrane

~Virus Replication~ Virus injects its DNA into a host cell Merges with host cell’s DNA As Host cell replicates DNA replicates as well Virus is Dormant The lysogenic cycle

The Lytic cycle Virus injects DNA into a host cell Host reads DNA and produces new viruses Host cell fills up with viruses until it pops or lyses

Mutations Point mutations (substitutions)- may or may not be a big deal Frame shift mutations (insertions or deletions)- always a big deal

Gene Mutations What’s the difference? Point mutation When a single base is switched

Example of a point mutation Sickle cell anemia One base change- one amino acid substitution Hemoglobin does not function normally

hemoglobin A protein in your blood that holds oxygen Sickle cell anemia is a point mutation problem

Other point mutations threonine glycine proline phenylalanine mRNA ACU – GGA – CCA -- UUC Change the last C to a U- what happens to the protein? Turn this into a U

Frame-shift mutations Deletion

Insertion

Which is worse? Point Mutation? Why? What does a point mutation do to the whole protein? Frame-shift Mutation? Why? What does a frame-shift mutation do to the whole protein?