Unit C3 - Molecular Biology Flashcards
What is each nucleotide made of?
- Phosphate Group
- Pentose Sugar
- Nitrogenous Base (with four different types - A, C, G, T)
What did Frederick GRIFFITH Discover?
The transforming principle → a chemical substance from one cell is genetically transforming another cell.
What did Avery, Macleod and McCarty Discover?
DNA-destroying enzymes prevent the transformation of genetic material from different bacteria.
What did Hershey and Chase Discover?
DNA was the material used to reproduce cells.
What did Levene Discover?
Determined that both RRNA and DNA were made up of long chains of nucleotides.
What did Chargaff Discover?
The Chargaff rule → # adienine = # Thymine, # Guanine = # Cytosine
What did Franklin Discover?
Used x-ray crystallography to analyze the structure of DNA.
DNA is a helical structure with two repeating patterns
Nitrogenous basse = inside
Sugar-phosphate backbone = outside
What did Watson and Crick Discover?
Double helix model for the structure of DNA.
What is semi-conservative Replication:
Each parent strand of DNA is conserved and functions as a template for the creation of its complementary strand.
What does Helicase do?
An enzyme that breaks nucleotide pairs apart
What does DNA Polymerase do?
Fuses together free floating nucleotides.
What is replication origin?
Where replication starts.
What are the three steps of DNA replication? What are the processes in each step?
Initiation → Helicase binds to the replication origin.
Elongation → with the help of primase, DNA polymerase adds nucleotides in the five-prime to 3 prime direction.
Termination → as soon as the newly formed strands are complete, they rewind automatically into a helix
What are anti-parallel strands?
The two “backbones” of the DNA are in opposite directions. (three prime to five prime, and the opposite side is five prime to three prime)
What is RNA Primer?
used as the starting point for the attachment of new nucleotides which later get removed by the DNA primer
What is primase?
An enzyme that constructs the RNA primer
What is the leading strand?
A Replicated strand that is Continuously made from the five prime to the three prime directions.
What is the lagging strand?
A Replicated strand that is Continuously made from the five prime to the three prime directions.
what are the three most important characteristics of the genetic code?
Redundant → more than one codon can code for an amino acid
Continuous → Reads as a series of three-letter codons without spaces
Universal → All living organisms build proteins with this genetic code.
Does DNA leave the nucleus during protein synthesis?
No, RNA does.
What are the four nucleotides of DNA?
Adenine, Thymine, Cytosine, Guanine.
What are the four nucleotides of RNA?
Adenine, Uracil, Cytosine, Guanine
What are the two parts of protein synthesis? What are they used for?
Transcription → DNA is unzipped and mRnA is created
Translation → mRNA is translated into ribosomes with the help of tRNA to create chains of peptides to create amino acids.
What is the job of RNA polymerase?
Binds nucleotides together nucleotides in the 5 prime to 3 prime direction to construct the single-stranded mRNA molecule.
What are stop codons
Codes that do not code for amino acids but stop production.
When mRNA transcription is complete where does the mRNA go?
When mRNA is created, it leaves the nucleus through its pores and goes to the ribosomes.
What are transfer RNA (tRNA) Molecules?
Molecules that bring amino acids to the mRNA.
What is the mRNA initiator codon?
creates methionine and starts protein synthesis in the ribosome.
What are mutations?
Permanent changes in the genetic material of an organism
What are the 5 different types of mutations?
Point mutation, silent mutation, Mis sense mutation, Non sense Mutation, Framshift Mutations. (do not need to know in great detail)
What are spontaneous mutations?
Incorrect base pairing during DNA replication.
what are Mutagens
things that cause mutations.
What is Recombiant DNA?
DNA that includes genetic material from different sources
What is transgenic organisms?
Organisims that have recombnant DNA.
What are restriction enzymes?
Found in bacteria, they cleave specific nucleotide sequences.
What are sticky ends
complementary single stranded DNA tails
What is another term for restriction enzymes?
restriction endonuclease
Gel electrophoresis
Separation of DNA fragments according to mass and charge
