1. Lesson 7e: Nucleic acids: Information molecules
Helix – twisted
Re - again
Lesson 7e: Nucleic acids: Information molecules

2. Nucleic Acids
Examples
DNA
DeoxyriboNucleic Acid
RNA
RiboNucleic Acid

3. Nucleic Acids Function: genetic material stores information
genes
blueprint for new cells
blueprint for next generation
transfers information
blueprint for building proteins
DNA  RNA  protein
DNA
proteins

4. A T C G
Structure of DNA 1:14
DNA folding to make Chromosomes 2:21

5. Nucleic acids 5 different nucleotides Building block = nucleotides
nucleotide – nucleotide – nucleotide – nucleotide
5 different nucleotides
different nitrogen bases
A, T, C, G, U
Nitrogen bases I’m the A,T,C,G or U part!
phosphate
sugar
N base

6. Nucleotide chains Nucleic acids nucleotides chained into a polymer DNA
phosphate
sugar
N base
Nucleotide chains
Nucleic acids
nucleotides chained into a polymer
DNA
double-sided
double helix
A, C, G, T
RNA
single-sided
A, C, G, U
phosphate
sugar
N base
strong bonds
phosphate
sugar
N base
phosphate
sugar
N base

7. DNA Double strand twists into a double helix
weak bonds between nitrogen bases join the 2 strands
A pairs with T
A :: T
C pairs with G
C :: G
the two strands can separate when our cells need to make copies of it
It’s a helix or B sheet within a single region. Can have both in one protein but a specific region is one or another

8. Copying DNA Replication 2 strands of DNA helix are complementary
matching
have one, can build other
have one, can rebuild the whole
when cells divide, they must duplicate DNA exactly for the new “daughter” cells
Why is this a good system?

9. Newly copied strands of DNA
DNA replication
Copying DNA
pairing of the bases allows each strand to serve as a pattern for a new strand
The greatest understatement in biology!
Newly copied strands of DNA

10. Watson and Crick … and others…
1953 | 1962
Watson and Crick … and others…

11. Sample Question
Which of the following is true of a nucleic acid?
a. Nucleotides are made of a 5-carbon sugar, a nitrogen base, and a lipid.
b. DNA and RNA are examples of nucleic acids that are rarely seen in living things.
c. Nucleic acids are made of repeating units called lipids.
d. Nucleic acids store important information about cell division and the manufacturing of proteins.

12. Flash: Biology__The_Science_of_Life__DNA__The_Master_Molecule_of_Life
Before reading the choices, recall what you know about the topic. Then look for the answer.
TEST TIPS!