DNA Structure and Function Flashcards
What happened in 1869?
Friedrich Miescher investigated a compound found in the nucleus – nuclein (DNA)
What happened in the 1920s?
Chemical components of nuclein were discovered in 1920s, but took decades longer to prove DNA housed the genetic information and cause for heredity
What happened in the 1930s?
Joachim Hammerling verified that the genetic material was in the nucleus
What happened in 1952?
Alfred Hershey and Martha Chase proved with bacterial viruses that DNA was the hereditary material
What are the three main components that make up DNA?
-Pentose Sugar
-Phosphate Group
-Nitrogenous Base
What do these three main components make up?
Together they make up a nucleotide;
What makes up the human genome?
3 billion pairs of nucleotides make up the human genome
What are the 4 possible nitrogenous bases?
-Adenine (A)
-Thymine (T)
-Cytosine (C)
-Guanine (G)
Who was the key relationship between the bases discovered by?
Erwin Chargaff
What was this key relationship? What was it called?
-A = T
- C = G
-Chargaff’s Rule
What needed to be understood?
How DNA stores and transmits genetic information
Who began the study?
Rosalind Franklin along with Maurice Wilkins
Who then met with Franklin and Wilkins?
Watson and Crick
What did Watson and Crick use information for?
They used the information from the meet and their own ideas to create the first model – now known as the double helix
What is the double helix?
Two strands of repeating DNA nucleotides running in opposite directions
What is each strand of the double helix made up of?
Alternating phosphate groups and pentose sugars
What are attached to the backbone of the double helix?
Nitrogenous Bases
How are the nitrogenous bases laid out on the double helix?
One base on one strand bonds with its pair on the other strand
What is DNA Fingerprinting?
A technique used by scientists to distinguish between individuals of the same species using only samples of their DNA
How can DNA profiling solve crimes?
The pattern of the DNA profile is then compared with those of the victim and the suspect.
What happens if the profile matches the suspect?
It provides strong evidence that the suspect was present at the crime scene (NB:it does not prove they committed the crime).
What happens if the profile doesn’t match the suspect?
Then that suspect may be eliminated from the enquiry.
