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Who are these two famous characters of science?

Who are these two famous characters of science?. Mendel (1865): Inheritance

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Page 1: Who are these two famous characters of science?. Mendel (1865): Inheritance

Who are these two famous characters of science?

Page 2: Who are these two famous characters of science?. Mendel (1865): Inheritance

Mendel (1865): Inheritance

Page 3: Who are these two famous characters of science?. Mendel (1865): Inheritance

T.H. Morgan (1910): genes linked on chromosomes

Chromosomes are made of DNA and proteins

DNA and proteins are the two candidates for the genetic material

Page 4: Who are these two famous characters of science?. Mendel (1865): Inheritance

Griffith(1928): bacterial work- streptococcus pneumoniae

Transformation: change in genotype and phenotype due to assimilation of external substance (DNA) by a cell

Page 5: Who are these two famous characters of science?. Mendel (1865): Inheritance
Page 6: Who are these two famous characters of science?. Mendel (1865): Inheritance

Avery and team(MacLeod and McCarty)(1944): transformation agent was DNA

Page 7: Who are these two famous characters of science?. Mendel (1865): Inheritance

Hershey and Chase(1952): determine that DNA is the hereditary material and not proteins:

Page 8: Who are these two famous characters of science?. Mendel (1865): Inheritance
Page 9: Who are these two famous characters of science?. Mendel (1865): Inheritance

Watson & Crick(Wilkins, Franklin)(1953):The Double Helix

Page 10: Who are these two famous characters of science?. Mendel (1865): Inheritance

Basic Unit of Nucleic Acids = nucleotideSugar/ phosphate backboneNitrogen base

Page 11: Who are these two famous characters of science?. Mendel (1865): Inheritance

5 carbon sugar = ribosePhosphate group

Phosphodiester bond

Page 12: Who are these two famous characters of science?. Mendel (1865): Inheritance

In DNA there are four(make up the interior of the molecule):AdenineThymineCytosineGuanine

Two groups:Purines: double ringed structures

Adenine and GuaninePyrimidines: single ringed

structuresThymine and Cytosine

Page 13: Who are these two famous characters of science?. Mendel (1865): Inheritance

5’ to 3’5’ with the phosphate group3’ with the –OH group

Page 14: Who are these two famous characters of science?. Mendel (1865): Inheritance

Inward facing nitrogen base will pair with their complementary base

A will pair with T (two H- bonds)G will pair with G (three H- bonds)A double ringed structure will always pair with a single ringed structure to maintain width.

Page 15: Who are these two famous characters of science?. Mendel (1865): Inheritance
Page 16: Who are these two famous characters of science?. Mendel (1865): Inheritance

DNA strands are oriented in the opposite directions

Page 17: Who are these two famous characters of science?. Mendel (1865): Inheritance

Van der Waals attractions play a role in holding the DNA molecule together

Page 18: Who are these two famous characters of science?. Mendel (1865): Inheritance
Page 19: Who are these two famous characters of science?. Mendel (1865): Inheritance

Proposed the semiconservative model of DNA replication:

Page 20: Who are these two famous characters of science?. Mendel (1865): Inheritance

DNA polymeraseHelicasePrimaseDNA ligaseTopoisomerase

Page 21: Who are these two famous characters of science?. Mendel (1865): Inheritance

Sites where DNA replication beginsProkaryotes: one origin

Replication proceeds in two directions

Humans: hundreds maybe thousands of originsReplication proceeds in two directions

Page 22: Who are these two famous characters of science?. Mendel (1865): Inheritance

Replication bubble: unwinding and separation of the DNA strand

Replication fork: Y- shaped region at each end of the bubble

Page 23: Who are these two famous characters of science?. Mendel (1865): Inheritance

1. 2.

3.

4.

?’

?’

?’

?’

5.

Page 24: Who are these two famous characters of science?. Mendel (1865): Inheritance

Elongation catalyzed by DNA polymeraseE. coli bacteria adds nucleotides at

a rate of 500/secHumans add nucleotides at a rate

of 50/secNucleoside triphosphate:

Page 25: Who are these two famous characters of science?. Mendel (1865): Inheritance

Antiparallel elonagation:5’ – 3’ direction

Leading strandLagging strand

Okazaki fragmentsE. coli fragments: 1000- 2000 nucleotides Human fragments: 100 -200

Page 26: Who are these two famous characters of science?. Mendel (1865): Inheritance
Page 27: Who are these two famous characters of science?. Mendel (1865): Inheritance

Meselson & Stahl replication semiconservative;

Expt: varying densities of radioactive nitrogen

Page 28: Who are these two famous characters of science?. Mendel (1865): Inheritance

Briefly describe the role of the following enzymes involved in DNA replication: DNA polymerase IDNA polymerase IIIHelicaseDNA ligaseTopoisomerasePrimase

Page 29: Who are these two famous characters of science?. Mendel (1865): Inheritance

1. 2.

3.

4.

?’

?’

?’

?’

5.

Page 30: Who are these two famous characters of science?. Mendel (1865): Inheritance

How many primers are needed for the leading strand?

How many primers are needed for the lagging strand?

Page 31: Who are these two famous characters of science?. Mendel (1865): Inheritance

DNA replication ensures continuity of hereditary information:

Page 32: Who are these two famous characters of science?. Mendel (1865): Inheritance

1. Enzymes of DNA replication work as part of a large complex:

2. Replication process is probably a stationary processDNA polymerase “reels- in” the parent DNA

Lagging strand may may be looped

Page 33: Who are these two famous characters of science?. Mendel (1865): Inheritance

Pairing errors occur at the rate of 1 out of every 100, 000 base pairs

DNA polymerase proof reads each nucleotideIncorrectly paired nucleotides are immediately removed and replaced

Page 34: Who are these two famous characters of science?. Mendel (1865): Inheritance

Mismatch pair: Repaired by the action of nuclease(one of many different DNA repair enzymes)

Removes nucleotides damaged by chemicals or the environment

Page 35: Who are these two famous characters of science?. Mendel (1865): Inheritance

Telomeres= nucleotide sequences at the ends of the DNA moleculeContain a repeated unit TTAGGGDo not contain genesNo nucleotides addedProtects the molecule from the replication

processTriggers apoptosisMay contribute to the aging process

Page 36: Who are these two famous characters of science?. Mendel (1865): Inheritance

Catalyzes the lengthening of the telomeres in eukaryotic germ cells