BIOA01H3 Lecture Notes - Lecture 25: Semiconservative Replication, Vise, Cytosine
BIOA01 MODULE 3 GENE ACTION AND INHERITANCE
LEC 25
Nov 5, 2015
→ How de know that DNA is the hereditary material
* Hershey and Chase Experiment
- bacteriophages contained protein and DNA
- contains phosphorus not sulfur
P32 labels the viral DNA→ injected into cell during infection
Phage (bacteriophage): viruses that infect bacteria
- were allowed to infect bacteria grown on radioactive sulphur (S35)
containing bacterial medium
- phage infected bacteria grown on radioactive phosphorus (p32) containing
bacterial medium
how can we use this?
DNA gets inserted into bacterial cell , hereditary material is DNA where P32 is
located
→DNA Structure
Purines → Adenine (A)/ Guanine (G) (double cyclic structure)
Pyrimidines → Cytosine(C)/Thymine(T) (single cyclic structure)
3 prime end has 3 carbon
5 prime end has 5 carbon
→Watson and Crick (from Data from Wilkins and Franklin
- anti-parallel →one runs from 5 prime to 3 prime direction, and vise versa,
double-helix shape (2 DNA strands)
- complementary to each other
- * A’s and T’s held together by two hydrogen bonds/ C’s and G’s held
together by 3 hydrogen bonds)
→ Does DNA replicate semi conservatively?
a. semiconservative replication
- two different light DNA and two of mixture
b. conservative replication
- produces one old double strand of DNA and 3 brand new double strands of
DNA
c. dispersive replication
- old DNA and new DNA are intermeshed → old and new make up one
throughout
***ONLY MODELT AHT WORKS IS SEMI-CONSERVATIVE
→ DNA Replication experiment: Meselson and Stahl
find more resources at oneclass.com
find more resources at oneclass.com
3363410481 and 37710 others unlocked
18
BIOA01H3 Full Course Notes
Verified Note
18 documents
Document Summary
How de know that dna is the hereditary material. Bacteriophages contained protein and dna contains phosphorus not sulfur. P32 labels the viral dna injected into cell during infection. Were allowed to infect bacteria grown on radioactive sulphur (s35) containing bacterial medium. Dna gets inserted into bacterial cell , hereditary material is dna where p32 is located. Purines adenine (a)/ guanine (g) (double cyclic structure) Pyrimidines cytosine(c)/thymine(t) (single cyclic structure) (cid:498)3(cid:499) prime end has 3 carbon. Watson and crick (from data from wilkins and franklin. Anti-parallel one runs from 5 prime to 3 prime direction, and vise versa, double-helix shape (2 dna strands) complementary to each other. * a"s and t"s (cid:523)held together by two hydrogen bonds(cid:524)/ c"s and g"s (cid:523)held together by 3 hydrogen bonds) Does dna replicate semi conservatively: semiconservative replication. Two different light dna and two of mixture: conservative replication. Produces one old double strand of dna and 3 brand new double strands of.