1. Chapter 11
DNA, RNA and Proteins

2. Section 11.1 Summary – pages 281 - 287
What is DNA?
Deoxyribonucleic Acid- type of nucleic acid
DNA is the code for manufacturing all the proteins for an organism.
DNA is made of nucleotides
Section 11.1 Summary – pages

3. The structure of nucleotides
Nitrogenous base
Phosphate group
Sugar (deoxyribose)
Nucleotides have three parts: a simple sugar, a phosphate group, and a nitrogenous base.

4. Nucleotide Structure Sugar - deoxyribose .
Nitrogen Bases: adenine (A), guanine (G) cytosine (C), and thymine (T).
Cytosine (C)
Thymine (T)
Adenine (A)
Guanine (G)
Purines
Pyrimidines

5. Base Pairing Adenine – Thymine Cytosine - Guanine A - T A - T C-G A-T

6. The structure of nucleotides
In DNA, the amount of adenine is always equal to the amount of thymine, and the amount of guanine is always equal to the amount of cytosine.

7. The structure of DNA Nucleotides join together to form long chains
Phosphate groups and deoxyribose molecules- form the backbone of the chain
It is a double helix and is twisted

8. Section 11.1 Summary – pages 281 - 287
The sequence of nucleotides forms the unique genetic information of an organism.
Chromosome
Section 11.1 Summary – pages

9. REPLICATION

10. Section 11.1 Summary – pages 281 - 287
Replication
Before mitosis or meiosis, the chromosomes are copied – this is called DNA replication.
Happens during Interphase
The new DNA is identical to original DNA
Section 11.1 Summary – pages

11. Section 11.1 Summary – pages 281 - 287
DNA
Replication
Replication of DNA
Replication
Section 11.1 Summary – pages

12. Copying DNA New DNA molecule Original DNA Strand Free Nucleotides
New DNA Strand
Original DNA Strand
Original DNA

13. Section 11.1 Summary – pages 281 - 287
Replication of DNA
Click this image to view movie
Section 11.1 Summary – pages

14. RNA
Ribonucleic acid
type of nucleic acid
single stranded

15. Section 11.2 Summary – pages 288 - 295
RNA
Ribose
sugar is ribose
Section 11.2 Summary – pages

16. RNA Nitrogen bases: adenine – uracil cytosine - guanine NO thymine
Hydrogen bonds
Adenine

17. Comparing DNA and RNA DNA 1. double stranded 2. sugar – deoxyribose
3. nitrogen bases
- adenine-thymine
- cytosine-guanine
RNA
Single stranded
Sugar – ribose
Nitrogen bases:
- adenine- uracil
- cytosine- guanine

18. Genes and Proteins Proteins are made of amino acids.
The sequence of nucleotides in each gene contains the code for making the string of amino acids that make up a protein.

19. Section 11.2 Summary – pages 288 - 295
Transcription
1. DNA - instructions for making proteins (proteins are made of amino acids)
RNA transcribes the instructions from the DNA- mRNA
Section 11.2 Summary – pages

20. mRNA
Messenger RNA (mRNA), brings instructions from DNA in the nucleus to the ribosomes. (in the cytoplasm)

21. Difference in Replication and Transcription
Replication – forms a double stranded DNA molecule from the DNA in the nucleus and it is identical to the original DNA
Transcription – forms a single stranded RNA molecule called mRNA from the DNA that is in the nucleus

22. DNA separates – mRNA is assembled A A T C C G G G C
T U A
DNA
DNA

23. Section 11.2 Summary – pages 288 - 295
Transcription
Section 11.2 Summary – pages

24. Section 11.2 Summary – pages 288 - 295
Translation: From mRNA to Protein
mRNA is made in the nucleus and travels to the ribosomes in the cytoplasm.
- ribosomes are made of rRNA (ribosomal RNA)
ribosome attaches to the mRNA
tRNA –( transfer RNA) – brings the correct
amino acid to the ribosome to make the protein
Section 11.2 Summary – pages

25. Section 11.2 Summary – pages 288 - 295
RNA
Transfer RNA (tRNA) is the supplier. Transfer RNA delivers amino acids to the ribosome to be assembled into a protein.
Click image to view movie
Section 11.2 Summary – pages

26. Section 11.2 Summary – pages 288 - 295
Translation
Section 11.2 Summary – pages

28. Strand of mRNA
AUG UAA CGA CGA GAU GUG UGA
Codon – set of three nitrogenous bases that represent an amino acid (the order of the nitrogen bases is the recipe for the protein)

29. mRNA strand AUG UAC CGA CGA GAU GUG UGA
Methionine, Tyrosine, Arginine, Arginine, Aspartic Acid, Valine, Stop
Each codon represents an amino acid

30. Try one!!!! Write the amino acids that correspond to the codon!!!!
AUG UUU ACA AAA GGG GAG GUC UAA
methionene, phenylalanine, threonine, lysine, glycine, glutamic acid,valine,stop

31. AUG UUU ACA AAA GGG GAG GUC UAA
Now try something different- here is the mRNA – write what the DNA code was for this mRNA.
AUG UUU ACA AAA GGG GAG GUC UAA
TAC AAA TGT TTT CCC CTC CAG ATT

32. Review of Translation mRNA leaves the nucleus and goes to the ribosome
mRNA has the code for making the protein
tRNA brings the correct amino acid to the ribosome to make the protein

33. Any change in the DNA sequence
Mutation
Any change in the DNA sequence

34. Mutations
Body cell – damage to a gene may impair the function of the cell
- ex: cancer
Reproductive Cell – mutation could become a part of the genetic makeup of the offspring
-ex:genetic disorder, death

35. Types of mutations
Point mutation – a change in a single base pair in DNA – wrong amino acid
- ex: CCC – codon for proline
CGC(mutation) – codon for
arginine
Insertion – an extra base pair inserted – changes the codon
Deletion – a base pair is missing – again changes the codon

36. Results in a frameshift mutation- it shifts the reading of codons so has the wrong amino acids for the protein

37. Practice DNA strand: TAC AAA TGT TTT CCC CTC CAG ATT RNA strand:
AUG UUU ACA AAA GGG GAG GUC UAA
Amino Acids making up the protein:
methionene, phenylalanine, threonine, lysine, glycine, glutamate,valine,stop

38. Point mutation DNA strand: TAC AAA TGT TAT CCC CTC CAG ATT RNA strand:
AUG UUU ACA AUA GGG GAG GUC UAA
Amino Acids making up the protein:
methionene, phenylalanine, threonine, isoleucine, glycine, glutamate,valine,stop

39. Frameshift Mutation DNA strand: (deletion)
TAC AAA TGT TT CCC CTC CAG ATT
RNA strand:
AUG UUU ACA AA GGG GAG GUC UAA
AUG UUU ACA AAG GGG AGG UCU AAG
Amino Acids making up the protein:
methionene, phenylalanine, threonine, lysine,glycine,arginine, serine, lysine

40. Chromosomal mutations
Deletion-part of the chromosome is left out
Insertion- part of chromatid breaks off and attaches to its sister chromatid (duplication of genes on one chromosome)
Inversion – when a chromsome breaks off and reattaches backwards
Translocation- part of one chromosome breaks off and is added to a different chromosome

41. Causes of mutations Mutagen- any thing that causes a change in the DNA
- radiation, chemical , UV light, nuclear
radiation, asbestos,