DNA (Deoxyribonucleic Acid)

DNA Foldable Directions Make a shutter fold (lengthwise/hot dog)but overlap the left fold over the right. Fold the paper in half twice, make creases and cut the creases so you end up with 4 flaps per side

DNA Foldable Directions Label the left hand flaps A, T, C and G. Label the right hand flaps T, A, G and C. For each flap cut a shape so they fit together like a puzzle – A: square (out) – T: square (in) – C: triangle (out) – G: triangle (in)

It should look like this:

What is DNA? Deoxyribonucleic Acid Deoxyribonucleic Acid GENES – GENES – NUCLEOTIDES: NUCLEOTIDES: Double Helix Double Helix

What is DNA? Important Scientists: Important Scientists: – Rosalind Franklin: James Watson and Francis Crick:James Watson and Francis Crick:

What is DNA? DNA Nucleotide PPhosphate Group Group Nitrogenous base (A, G, C, or T) (A, G, C, or T) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose) “backbone” “rungs” of DNA ladder

Nitrogenous Base Pairing Bases held together byBases held together by DNA had specific pairing between the nitrogen bases:DNA had specific pairing between the nitrogen bases: TA G C

Nitrogenous Base Pairing Chargaff’s Rule about the same Their amounts in a given DNA molecule will be about the same and all 4 bases will equal to 100% If a DNA molecule contains 25% Adenine molecules how many Thymine molecules will there be? Guanine? Cytosine?

Nitrogenous Base Pairing DNA Double Helix P P P O O O P P P O O O G C TA

Nitrogenous Base Pairing Nitrogenous Bases PURINES PURINES PYRIMIDINES PYRIMIDINES Thymine (T) 3.Thymine (T) Cytosine (C) 4.Cytosine (C) T or C A or G

Nitrogenous Base Pairing BASE-PAIRINGS CG H-bonds T A

The Code of Life The “code” of the chromosome is the SPECIFIC ORDER that bases occur. The “code” of the chromosome is the SPECIFIC ORDER that bases occur. All living things contain DNA and reproduce All living things contain DNA and reproduce – Kingdoms: Bacteria Bacteria Protists Protists Fungus Fungus Plants Plants Animals Animals

The Code of Life Mushroom Panda Bear Flower E. coli Venus Fly Trap JellyfishDiatoms Algae Shark

Genetic Diversity… Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms. Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms.

Environmental factors that affect DNA Chemicals: Chemicals: – Addition of MgCl causes fish to develop only 1 eye Drugs: Drugs: – Causes deformities in children Pollution Pollution – Asthma and bronchitis

Environmental factors that affect DNA Temperature: Temperature: Light: Light: – Butterflies exposed to red light have brighter colors Temp. Cont’d Temp. Cont’d – Some reptiles change sex based on temp.

AMAZING DNA FACTS… DNA from a single human cell extends in a single thread for almost 2 meters long!!! DNA from a single human cell extends in a single thread for almost 2 meters long!!! It contains information equal to some 600,000 printed pages of 500 words each!!! It contains information equal to some 600,000 printed pages of 500 words each!!! (a library of about 1,000 books)

LET’S REVIEW DNA… 1.Summarize the relationship between genes & DNA. 2.Describe the overall structure of the DNA molecule. 3.What are the 4 kinds of bases?