Nucleic Acids And DNA Replication Flashcards
Structure of nucleotides
One to three phosphate groups linked by a phosphoester bond to a pentode sugar which is linked to a nitrogenous base by a glycosidic bond.
What makes purines and pyrimidines different on a nitrogenous base?
Purines are linked through N9 (Adenine and Guanine)
Pyrimidines are linked through N1 (Uracil and Thymine and Cytosine)
What is different between a RNA and DNA?
Ribose (RNA) has an OH group on the second carbon.
Deoxyribose (DNA) doesn’t have an OH group on the second carbon.
What does the phosphate groups do to a nucleotide?
Makes it negatively charged.
Function of nucleotides
Forming nucleus acid polymers
Functions of nucleotides as monomers
Biological energy carriers through the high energy phosphate bond
To form coenzymes
Intracellular signalling molecules
Complementary Watson-Crick base pairs are…
Two anti parallel polynucleotide strands of DNA that can be held together by H bonds between complementary base pairs of double stranded nuclei acids.
Stages of DNA denaturation and renaturation
Double strands can be separated to single strands
H bonds break from rising temperature
Slowly cool for renanturation
Regenerate the hydrogen bonds
Mechanism for heredity
Genome contains the genetic program that instructs a cell how to behave.
Where in the eukaryotic cell is the DNA found?
Nucleus and mitochondria.
Why do we need DNA replication?
Before a cell can divide, it’s DNA needs to be copied to obtain two genetically identical daughter cells.
Why does DNA need to accurately copy its DNA and try to avoid mistakes?
Reduce the risk of diseases in human cells
Reduce the risk of developing drug resistance
What type of process is DNA replication?
Semi-conservative process
What are the 4 stages of the semi-conservative process of DNA replication?
Replication fork formation
Initiation
Polymerase elongation
Termination
What does DNA polymerase need to start?
Short RNA primer
