HAPPY TUESDAY Bellwork: Draw and Label
Reminders Tomorrow is a PSAT Day (1 st – 4 th will not meet) Notecards will be due on Thursday Test will be next week
Essential Question: What are the components of DNA?
The nucleic acids we’ll talk about in biology are DNA and RNA Deoxyribonucleic acid = DNA
DNA is the biomolecule used to pass on genetic information to the next generation. So…your DNA is half mom, half dad!
The monomer of DNA is called a nucleotide, which has: 1. 5-carbon sugar (deoxyribose) 2. phosphate group 3. nitrogenous base. This means that the elements in a nucleic acid are: C, H, O, N, and P
Draw and label this nucleotide in your notes
There are 4 kinds of nitrogenous bases in DNA. Adenine (A), Guanine (G), Cytosine (C), & Thymine (T)
A lesson from Jurassic Park...
DNA base pairing rule: (A) adenine and (T) thymine pair together with 2 hydrogen bonds. (C) cytosine and (G) guanine pair together with 3 hydrogen bonds. Hydrogen bonds are weak (easily broken) bonds
The differently shaped bases are bonded together antiparallel to one another (5’ 3’) When enough bases are linked together, the DNA ladder will twist into a double helix shape.
In a Eukaryotic organism the DNA double helix will coil around histones (proteins) and eventually be packed together into chromosomes. DNA is found in the nucleus in Eukaryotic cells.
In a prokaryotic organism, DNA is found in the cytoplasm.
Important to Remember: All living things have DNA! Scientists refer to this as a “common genetic code” The sequence of bases matters! The order determines the organism.
Building DNA On your piece of paper, determine your sequence for your DNA strand. – You must make 4 pairs – For example, if your first base is A it must pair with T Get the colored squares to match your sequence. Make your nucleotides by drawing circles for you phosphate groups and a pentagon for your sugars. Have a teacher check it off before you glue down your pieces! P S T Example: Base Color-Code: A = Pink T = Green C = Light Blue G = Dark Blue Small Group CHAMPS