Chapter 2: Nucleic Acids Convey Genetic Information Flashcards
Homopolymers built from single enzymes are …
Lipids and carbohydrates
Polypeptide chains, non repetitive heteropolymers are called …
Proteins
What is the Central Dogma?
DNA –> RNA –> Protein
This procedure involves bacteria culture exposed to UV light and grown on a completely different media
Replica plating
The major classes of macromolecules
Lipids and carbohydrates
Proteins
Nucleic Acid
Polynucleotide chains are called …
Nucleic acid
Can the order of amino acids (which are non-repetitive) be determined by enzymes
Enzymes cannot specify order for non-repetitive heteropolymers
Grifftih’s experimented with _________ __________
Streptococcus pneumoniae
The Two strains used in Griffith’s pneumoniae are …..
- Rough strain (R)
2. Smooth strain (S)
True or False:
The Rough strain (R) of Griffith’s Pneumoniae experiment is non-pathogenic
True
True or False:
The smooth strain (S) of Griffith’s pneumoniae experiment is non-pathogenic
FALSE Smooth strain (S) is pathogenic (virulent), has a polysaccharide capsule to protect itself from the immune system
True or False:
Non-viruent R strains gain virulence when mixed with heat-killed S virulent strains.
True
Transformation is the process by which …
R strains were transformed into S strains by heat killed extracts of virulent S
What experiment set the stage for identifying DNA as the genetic material
Griffith’s Pneumonia experiment
Who followed up on Griffiths experiment and discovered that DNA was the transforming agent
Oswald Avery
The avery experiment demonstrated that DNA was the genetic material because
S. pneumoniae extracts digested with deoxyribonuclease disrupted the transformation
Chargaff’s Experiment consist of …
A=T
G=C
Disproves the tetra-nucleotide hypothesis
Hershey Chase experiment involved studying
Bacteriophage T2, a virus that infects a bacterial host
Bacteriophage undergoes 4 steps:
1) absorption
2) penetration
3) replication
4) release of virions
The first to synthesize ATP and showed DNA chains are held together by 3’–>5’ phosphodiester bonds
Alexander Todd
Rosalind Franklin
Took an image of DNA which confirmed DNA is helical and composed of two strands
If Hershey and Chase found S(35) in progeny phages rather then P(32), their experiment would have demonstrated that …
phage protein enters the host cell
Nucleotide is the composition of ..
Base, sugar, and phosphate
Synthesis direction of DNA strand is
5’ –> 3’
DNA template is read
3’ –> 5’
Who studied DNA replication using N(14) and N(15) diffetential labeling of DNA and cesium chloride density gradient centrifugation to show separation of complementary strands during DNA replication?
Meselson and Stahl
Meselson and Stahl’s conservative replication is …
One daughter dsDNA is heavy (both original strands) and the other daughters dsDNA is light (both newly synthesized strands)
Meselson and Stahl’s semiconservative replication is …
Each of two daughters dsDNA should be of hybrid density (one original. one newly synthesized strand)
Meselson and Stahl’s dispersive replication is …
dsDNA strands broken every ~10 bp and used to prime synthesis. Both strands contain both old and new DNA, after the first few generations DNA is predominately light
Who proved DNA replication is semiconservative
Meselson and Stahl
In the Meselson and Stahl experiment, when starting with N(15) DNA, what would be found after one generation of replication when switching to N(14)
Hybrid DNA only (N(15)/N(14))
DNA –> RNA
What is the process called?
Transcription
RNA –> Protein
Translation
True of False:
RNA has an OH on the 2’ carbon
TRUE
Alternator adaptor molecule
Where amino acids are first attached to a specific adaptor that recognize both the amino acid and RNA. Proposed by Crick.
Aminoacyl-tRNA
- Amino acid + ATP –> aminoacyl-AMP
- Aminoacyl-AMP +tRNA –> AMP +aminoacyl-tRNA (acyl linkage)
Transcription uses a ________ that recognizes sequences at -10 and -35
Sigma factor
What are the two types of termination?
Rho dependent and Rho independent
