1. Nucleic Acids

2. Nucleic Acids
Nucleic acids (polymer) are long chains of nucleotides (monomer).
A nucleotide is composed of phosphate, sugar, and a nitrogen base.

3. Nucleic Acids There are 2 types of nucleic acids: DNA RNA
Functions of nucleic acids:
Store/transmit genetic information
Instructions for making proteins

4. DNA

5. DNA DNA stands for Deoxyribonucleic Acid.
DNA is shaped as a double helix because it looks like a twisted ladder
**Designed by Watson and Crick
DNA contains our genetic information and is stored in chromosomes in the nucleus of our cells.

7. DNA
The sugar for DNA is called deoxyribose sugar.
Sugar

8. DNA Nitrogen Bases There are 2 groups of nitrogen bases: Purines
Double-ringed structures
Pyrimidines
Single-ringed structures
Nitrogen base

9. DNA Nitrogen Bases There are 4 types of nitrogen bases found in DNA
Adenine(A) Guanine(G) Cytosine(C) Thymine(T)

10. DNA Nitrogen Bases **Therefore…
Adenine(A) and Guanine(G) = Purines (double ringed)
Cytosine(C) and Thymine(T) = Pyrimidines (single ringed)

11. Chargaff’s Rule nucleotide
Erwin Chargaff
Complementary Base Pairing
# A = # T and # C = # G
Therefore…
A pairs with T and C pairs with G

13. Video
Video (4:21)

14. Practice on your own!
Complete the following complementary base pairing:
A T G C A G G C A T

15. Practice on your own!
Complete the following complementary base pairing:
A T G C A G G C A T
T A C G T C C G T A

16. Let’s try again! - Practice on your own!
Complete the following complementary base pairing:
G C T T A A G T C A G C

17. Let’s try again! - Practice on your own!
Complete the following complementary base pairing:
G C T T A A G T C A G C
C G A A T T C A G T C G

18. Bonding Hydrogen bonds hold the nitrogen bases together.
The hydrogen bonds are weak bonds.
Hydrogen bond

19. DNA’s Orientation DNA’s double helix runs antiparallel to each other
This means that the 2 strands run in opposite directions of each other

20. DNA’s Orientation There are 2 ends to a nucleic acid:
5’ (“5 prime”): the phosphate end
3’ (“3 prime”): the -OH end

21. DNA’s Orientation One DNA strand runs 5’ to 3’
The other DNA strand runs 3’ to 5’

22. DNA The nucleotide sequence is very important Unique for each species
Unique for each individual
The more alike two species, the more alike their DNA

23. RNA Structure

24. RNA RNA stands for Ribonucleic Acid. RNA is single stranded.
RNA decodes the genetic information stored in DNA and can travel in our cells

25. RNA
The sugar for RNA is called ribose sugar.
Sugar

26. RNA There are 4 different nitrogen bases for RNA Cytosine (C)
Guanine (G)
Adenine (A)
Uracil (U)
A and U pair together
C and G pair together
Nitrogen base

27. Types of RNA
Messenger RNA (mRNA) - carries the DNA message from nucleus through cytoplasm to ribosome.
*Notice single stranded
*Notice nitrogen base is Uracil, not Thymine G U A G C U A

28. Types of RNA 2. Ribosomal RNA (rRNA) - makes up ribosomes
RNA glob up along with proteins to make ribosomes
Ribosomes are where proteins are made.

29. Types of RNA 3. Transfer RNA (tRNA) - Links amino acids together
A single RNA chain folded into T-shape
Location - cytoplasm and ribosomes

30. Types of RNA

31. DNA vs RNA video
video (4:43)

33. DNA & RNA DNA = Deoxyribonucleic Acid RNA = Ribonucleic Acid
Double stranded
Single stranded
Deoxyribose sugar
Ribose sugar
Nitrogen bases = A & T; G & C
Nitrogen bases = A & U; G & C **(U=Uracil)**
Replicates DNA → DNA
Does not replicate
Only one type
3 types: mRNA, rRNA, tRNA