DNA

DNA Deoxyribonucleic Acid A cell’s code / recipe / blueprint Biological instructions that make each species unique Genetic instructions used in the development and functioning of all known living organisms

What Does DNA Look Like? Similar to a ‘twisted ladder’ Each side of the ladder is made up of SUGAR-PHOSPATE MOLECULES Sugar group  deoxyribose Phosphate molecule Rungs(steps) of the ladder are nitrogen bases DNA has 4 types of nitrogen bases Nitrogen bases are connected by hydrogen bonds

NITROGEN BASES 4 types of Nitrogen Bases Adenine (A) Thymine (T) Guanine (G) Cytosine (C)

NITROGEN BASES Nitrogen bases occur in pairs in DNA. Adenine pairs with Thymine Guanine pairs with Cytosine Like pieces of a puzzle, each base bonds only with its correct partner.

If this code makes up one side of the DNA, what would the code be for the other side? A T C G A A C T T G A C A G

If this code makes up on side of the DNA, what would the code be for the other side? A T C G A A C T T G A C A G T A G C T T G A A C T G T C

1 base + 1 Sugar + 1 Phosphate = Nucleotide

Who Discovered DNA? James Watson and Francis Crick Rosiland Franklin, a woman, discovered the double helix shape of DNA and had the best X-ray picture at the time. Maurice Wilkin, her colleague, didn’t want a woman to get the credit for discovering DNA so he stole her picture and gave it to Watson and Crick. The picture along with their research help Watson and Crick create the first correct model of DNA. Watson, Crick, and Wilkin were awarded the Nobel Peace Prize in 1962. Franklin died of cancer 4 years earlier.

Joined Nucleotides = GENES Gene  sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Each cell in the human body contains about 25,000 to 35,000 genes Genes carry information that determines your traits. Traits are specific features you inherit from your parents.

PROTEIN Groups of 3 nucleotides from a DNA sequence make AMINO ACIDS Ribosomes connect amino acids into long chains Long chains of amino acids = PROTEIN Proteins are the building blocks for everything in your body. Bones and teeth, hair and earlobes, muscles and blood, all are made up of proteins. Those proteins help our bodies grow, work properly, and stay healthy.

CHROMOSOMES GENES + PROTIENS (built with the ribosomes and codes of DNA) = CHROMOSOMES There are hundreds to thousands of genes on each chromosome Chromosomes are located in the nucleus of the cell Each person has 23 pairs (46 total) of chromosomes. 23 chromosomes come from your father, 23 from your mother.

The DNA coils around proteins made up of amino acids

DNA REPLICATION DNA unwinds. The original strands serve as templates for two new strands. DNA POLYMERASE connects to the original strands and begins to create new DNA. Once DNA is replicated, the chromosome also splits.

MUTATIONS A mutation is a permanent change in the DNA sequence of a gene. Mutations in a gene's DNA sequence can alter the amino acid sequence of the protein. Mutations can be positive, negative, or neutral EX: Disease, missing body part/function, heightened senses, bigger and stronger, doubled jointed Mutations randomly cause adaptations

TYPES OF MUTATIONS Environmental Factors DNA Replication Error Sunlight (skin cancer, wrinkles, etc), Smoking (lung or throat cancer, lung disease, etc) Radiation DNA Replication Error Point Mutation Frame-shift Mutation

POINT MUTATION A point mutation is a simple change in one base of the gene sequence ( A paired with G instead of T). This is equivalent to changing one letter in a sentence, such as this example, where we change the 'c' in cat to an 'h': The fat cat ate the wee rat. Point Mutation: The fat hat ate the wee rat. The gene will now have a mutation, or change, compared to the original.

FRAME-SHIFT MUTATION In a frame shift mutation, one or more bases are inserted or deleted (A, T, C, or G accidentally doesn’t get copied), the equivalent of adding or removing letters in a sentence. Because our amino acids are created from DNA in three letter "words“ or codes, adding or removing one letter changes all of the following words. An example of a frame-shift mutation using our sample sentence is when the 't' from cat is removed, but we keep the original letter spacing: The fat cat ate the wee rat. Frame Shift: The fat caa tet hew eer at.