Module 5 - Notes Flashcards
What was Mendel’s contribution to the discovery of DNA?
Inheritance
Chromosomal theory of inheritance
Who was responsible for the “one gene - one polypeptide” thinking?
Beadle and Tatum
When was DNA discovered?
Late 1800s
When did scientists make the connection between DNA and inheritance?
1950’s
What was the significance of Griffith’s transformation experiments?
He showed that hereditary information could be transferred between bacteria using bacteria and mice
What was the advancement of the Avery, MacLeod and McCarty experiment?
They developed a way to test (prove) DNA was responsible for inheritance.
How did Alfred Hershey and Martha Chase contribute to identifying DNA was responsible for inheritance?
They confirmed that DNA was responsible for inheritance with experiments with bacteriophages.
32P-labelled DNA and 35S-labelled protein coat marked bacteriophages to test if viral protein or viral DNA entered the host cell.
What were the results of the experiment by Alfred Hershey and Martha Chase?
After centrifugation
The 35S-labelled protein coat remained in the pellet and the 32P-labelled DNA was found in the supernatant (bacteria)
What does it mean to have C & G rich bacteria?
They have more Cytosine and Guanine in the genome.
What makes up DNA?
Deoxyribose sugar
Phosphate
Nitrogenous base
What is meant by 5’ to 3’ and vice versa?
refers to directionality
Nucleoside triphosphates combine with each other by covalent bonds known as 5ʹ-3ʹ phosphodiester bonds to form the sugar-phosphate backbone of DNA
Do DNA strands run parallel or antiparallel to each other?
antiparallel
The nitrogenous bases are complementary
A - T and C- G
The sugar-phosphate backbone runs from 5’ to 3’ on one side and 3’ to 5’ on the other side.
What happens when DNA is denatured?
The bonds break between the nitrogenous bases.
What causes DNA to denature?
heat
95-100 degrees celsius will break the bonds.
What is the function of DNA?
Contains genetic information
There is no structural function.
How is DNA organized in cells?
Organized into a chromosome
What do Eukaryotic chromosomes look like?
Linear (uses the protein histone)
Haploid or diploid
multiple copies
Histone is present
What do prokaryotic chromosomes look like?
single copy
circular (supercoiled by topoisomerase)
haploid
lack histone
What do Archaea chromosomes look like?
Have both circular and linear
supercoil & histone
Mix of both.
What are extrachromosomal DNA?
genes that are non-essential
plasmids - found in archaea & bacteria
Mitochondrion & Chloroplast in Eukaryia
If a DNA strand contains the sequence 5’-ATTCCGGATCGA-3’ which of the following is the sequence of the complementary strand of DNA?
A. 5’-ATTCCGGATCGA-3’
B. 5’-TCGATCCGGAAT-3’
C. 5’-TAAGGCCTAGCT-3’
D. 3’-TAACCGGTACGT-5’
B. 5’-TCGATCCGGAAT-3’
Reverse complementary
What is the central dogma?
The flow of information
DNA -> RNA -> Protein
What is the process from DNA to RNA?
Transcription
What is the process from RNA to Protein?
Translation
(a new language)