Exam 3 (mean 76%) A70-63 B62-56 C55-49 D48-42 F41-0

Today-Ch 13 Announcements – Look for Chapter 12 and 13 quizzes posted this weekend. –Exam 4 covers Chapters 12, 13 and 16 (last exam you can drop. Everyone must take the final exam)

Biology 190 Chapter 16 pictures

DNA Replication occurs at the “S” stage of mitosis

Fig 5.26 Nucleotides U

ACCCCAGACCCCAG Fig 16.5 One DNA strand.

Fig 16.6 Double Helix ACCCCAGACCCCAG -T -G -T -C

Chargaff’s Rule

Question 16.1

Functions of Proteins Structural Catalytic activity Immunity Regulation Poisons Transport molecules Hormones Fluid and electrolyte balance Sources of energy

Fredrick Griffith’s Experiments Polysaccharide Coat

Fredrick Griffith’s Results Live R-strain picked up DNA from the S-strain. Contains genes for “smooth coat”.

Alfred Hershey and Martha Chase

How viruses (phages) infect bacteria

Fig 16.4 Hershey and Chase

Watson and Crick

Rosalind Franklin’s Data (Maurice Wilkins’ Lab)

What exactly IS the structure of DNA?

Chargaff’s Rule

Nucleotide base pairing

Fig 16.7 Structure of DNA

Nobel Prize WilkinsCrickWatson

Figure 16.9 Semiconservative Model for DNA Replication Parental strands (template strands) Daughter strands

DNA Origin of Replication Bacteria have one origin of replication. Fig Eukaryotic organisms have multiple origins of replication.

Unwinding DNA Single-stranded Binding Proteins

Nucleoside Triphosphate

Fig DNA Polymerase (Daughter strand) (Parent strand) (Old strand) P

Questions 6.3 & 6.4

Fig Replication Fork Leading Strand 5’ 3’ Lagging Strand 5’ 3’ 5’ 3’ 5’ 3’ Old strands Parent strands Template strands

Fig DNA Ligase DNA Polymerase III

Fig DNA polymerase needs a 3’ -OH group

Fig 16.16

Fig Review of Bacterial DNA Replication Helicase SS binding proteins

Fig DNA shortening and telomeres

Mismatch repair 2 Purines = bulge 2 Pyrimidines = dimple TC GA

Fig Excision Repair

Xeroderma Pigmentosa

In very, very, vary rare cases mutations have a selective advantage