The document summarizes key concepts about DNA, RNA, and protein synthesis. It describes Griffith's experiments which discovered genetic transformation through DNA and Avery's experiments identifying DNA as the transforming factor. It also discusses Hershey and Chase's experiments confirming that DNA is the hereditary material in viruses. The structure of DNA and how it replicates is outlined. Finally, the document explains the flow of genetic information from DNA to RNA to protein and the major steps in transcription and translation.

1. DNA, RNA, and Protein
Synthesis
Chapter 10

2. Section 1
DISCOVERY OF DNA

3. Griffith’s Experiments
• Fredrick Griffith studied bacteria that
cause pneumonia
– Some strains, or types, were harmful and
caused pneumonia in mammals (smooth)
– Other strains were harmless and did not
cause pneumonia (rough)

4. Griffith’s Experiments
• Used the two strains of bacteria in four
experiments
• Discovered that genetic material can be
transferred from one cell to another and
change those cells
• He called this transformation

5. Griffith’s Experiments

6. Avery’s Experiments
• Oswald Avery wanted to find out what
factor caused the transformation in
Griffith’s experiments
• Discovered that the factor was DNA

7. Hershey-Chase Experiment
• Experimented with bacteriophages –
viruses that infect bacteria
• Confirmed that DNA is the hereditary
molecule

8. Hershey-Chase Experiment

9. Section 2
DNA STRUCTURE

10. DNA Double Helix
• Structure of DNA discovered in 1953 by
James Watson and Francis Crick
• Used Maurice Wilkins and Rosalind
Franklin’s x-ray picture of DNA to help

11. DNA Nucleotides
• Made of two long strands of nucleotides
– Each nucleotide contains three parts
• Five-carbon sugar (deoxyribose)
• Phosphate group
• Nitrogenous base

12. DNA Nucleotides

13. Bonds Hold DNA Together
• Structure is similar to
a spiral staircase
– Alternating sugar and
phosphate molecules
= side handrails of the
staircase
– Base pairs = steps of
the staircase

14. Nitrogenous Bases
• Four kinds of bases
– Adenine
– Guanine
– Thymine
– Cytosine

15. Complementary Bases
• Base-pairing rules:
• cytosine always pairs with guanine
• adenine always pairs with thymine

16. Complementary Bases
• What is the complementary sequence of
bases for the following strand of DNA?
• ACCTGTGAGAC
• TGGACACTCTG

17. Section 3
DNA REPLICATION

18. DNA Replication
• DNA replication is the process by which
DNA is copied in a cell before a cell
divides

19. Steps of DNA Replication
1. Enzymes called
helicases separate
the DNA strands

20. Steps of DNA Replication
2. Enzymes called DNA
polymerases add
complementary
nucleotides to each
of the original
strands

21. Steps of DNA Replication
3. DNA polymerases
finish replicating the
DNA and fall off
– Result is two separate
and identical DNA
molecules

22. DNA Errors in Replication
• DNA replication is usually very accurate
– Only about one error occurs for every billion
nucleotides
• When mistakes occur, a change in the
nucleotide sequence results in a mutation

23. Section 4
PROTEIN SYNTHESIS

24. Flow of Genetic Information
• DNA RNA protein

25. RNA Structure and Function
• RNA is very similar to DNA – long strand
of nucleotides

26. RNA Structure and Function
• RNA is different from DNA in the following
ways:
– Contains the sugar ribose instead of
deoxyribose
– Contains uracil instead of thymine
– Single-stranded
– Much shorter than DNA

27. Types of RNA
• There are three major types of RNA that
each play a different role in protein
synthesis

28. Types of RNA
• Ribosomal RNA
(rRNA) – makes up
part of the ribosome

29. Types of RNA
• Messenger RNA (mRNA) – carries the
message from DNA in the nucleus to the
ribosomes in the cytoplasm

30. Types of RNA
• Transfer RNA
(tRNA) – transfers
amino acids to the
ribosome to make a
protein

31. The Genetic Code
• The genetic code is the rules for how a
sequence of bases codes for a particular
amino acid
• Each group of three nucleotides is called a
codon and codes for an amino acid

32. The Genetic Code

33. Transcription
• Instructions for a gene coded in DNA are
rewritten into an RNA molecule

34. Translation
• Translation = the making of a protein

35. Steps of Translation
1. mRNA is fed through
a ribosome three
bases at a time

36. Steps of Translation
2. Molecules of tRNA translate the mRNA code by
picking up a specific amino acid from the
cytoplasm

37. Steps of Translation
3. In the ribosome, bases on the tRNA match
with bases on the mRNA like pieces of a
puzzle

38. Steps of Translation
4. tRNA releases their amino acids and they
become linked in a chain