DNA Structure

Which fields are DNA important in?

Medical field, forensics, agriculture. Examples: gene therapy, gel electrophoresis, and GMOs.

Where are our genes? What are chromosomes made of?

Chromosomes; DNA

What is the “backbone” of the DNA helix made of?

Alternating deoxyribose sugars and phosphates (the nitrogenous bases are on SUGAR).

What are the rungs of the DNA helix made of?

Nitrogenous bases

One strand of DNA is a polymer of ________.

Nucleotides

What holds the nitrogenous bases together?

Hydrogen bonds

Chargaff’s Rule

Adenine is always paired with thymine. Cytosine is always paired with guanine.

What is so important about the order the nitrogenous bases are placed?

The order of the bases are important in determining the unique traits that one holds.

Purines have ___ ring(s). Purines include __________ and _________.

2; adenine; guanine

Pyrimidines have ___ ring(s). Pyrimidines include _________ and __________.

1; cytosine; thymine.

Pyramids have Cleopatra and Tut in them.

Fred Griffith

He mixed different strains of bacteria together and discovered transformation (harmless bacteria become harmful when mixed with harmful bacteria). The DNA pieces that were transferred are called recombinant DNA.

Oswald Avery and Erwin Chargaff

The two of them discovered that heat kills genetic material.

Chargaff: Found that nitrogenous bases have an equal ratio

Avery: Studied further and found that DNA stores and transmits genetic information from one generation to the next

Rosalind Franklin

Took an x-ray of DNA, the first “photo”

James Watson and Francis Crick

Used Franklin’s images to develop the double helix model of DNA.

Alfred Hersey and Martha Chase

Used bacteriophages to figure out how a virus’s DNA got inside their host. Determined that a virus’s genetic material is indeed DNA and NOT a protein.

Human Genome Project

A discovery led by a team of scientists/researchers that studied every gene in the human body