DNA presented by Mrs. Sanford 7th Grade Life Science Lost Mountain Middle School

DNA (Deoxyribonucleic Acid) a master copy of instructions for cell structure and function compared to: an agenda a set of blueprints an owner’s manual chemical code

DNA (Deoxyribonucleic Acid) chemical code gives you your characteristics - internal and external traits like hair color, eye color, height, heartbeat, hearing, personality, talents

DNA (Deoxyribonucleic Acid) chemical code organic compound contains carbon nucleic acid

DNA (Deoxyribonucleic Acid) structure (what it looks like) three dimensional double helix spiral staircase twisted ladder

DNA (Deoxyribonucleic Acid) structure sides or “handrails” are made of sugars and phosphates ‘ribo’ is for ribose, a sugar

DNA (Deoxyribonucleic Acid) structure cross pieces, “rungs” or “steps” are made of nitrogen base pairs same two bases always pair adenine, thymine (A, T) cytosine, guanine (C, G)

DNA (Deoxyribonucleic Acid) discovery/history 1950’s x-rayed by Rosalind Franklin Rosalind Franklin DNA X-ray

DNA (Deoxyribonucleic Acid) discovery/history 1950’s -1960’s Maurice Wilkins gives Franklin’s x-rays to Watson and Crick Francis Crick and James Watson make a model of DNA

DNA (Deoxyribonucleic Acid) discovery/history 1960’s Franklin dies of cancer Wilkins, Watson, and Crick share a Nobel Prize for the model

DNA (Deoxyribonucleic Acid) DNA Model Wilkins Watson and Crick DNA Model Sketch

DNA (Deoxyribonucleic Acid) DNA replication copying happens in the cell cycle during interphase Watson and Crick also modeled this

DNA (Deoxyribonucleic Acid) DNA replication enzymes break apart the bases RNA collects extra bases from the cytoplasm

DNA (Deoxyribonucleic Acid) DNA replication the extra bases pair with the broken DNA strands new handrails form from sugars and phosphates

DNA (Deoxyribonucleic Acid) DNA replication two new strands have been created

DNA (Deoxyribonucleic Acid) Mutation damaged chromosomes (strands of DNA) mistakes in the DNA

DNA (Deoxyribonucleic Acid) Mutation deleted or inserted base pairs, “steps” example: albinism

What does DNA look like? Draw picture in the space to show what you think the structure of DNA looks like. examples

What does DNA do? Draw picture in the space to show what you think the function (job) of DNA is.

Your Turn How is your model like the real DNA? How is it different? Use the model kit to make a replica of DNA Review kit colors Same two bases always use same two colors adenine and thymine (A, T) cytosine and guanine (C, G) How is your model like the real DNA? How is it different? Where is DNA found in cells? What does it look like when inside the cell’s nucleus?