HAPPY TUESDAY

Bellwork: Draw and Label

Reminders• Tomorrow is a PSAT Day (1st –

4th 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 group3. 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 = PinkT = GreenC = Light BlueG = Dark Blue

Small Group CHAMPS