nucleotides+nucleic acids Flashcards
What do protease enzymes do to DNA?
Protease enzymes hydrolyse the proteins associated with DNA (the histones).
What bonds hold DNA chains together?
DNA chains are held together by phosphodiester bonds in the backbone and by hydrogen bonding between base pairs.
Which bases pair together in DNA?
A bonds to T and G bonds to C.
What role does phosphate play in DNA structure?
Phosphate is important in DNA structure.
How does detergent assist in DNA extraction?
Detergent disrupts the cell surface membrane and the nuclear envelope to help release the contents of the nucleus.
What is the process of DNA precipitation?
Salt helps DNA to shed water/precipitate, and protease breaks down the histones. Ethanol is added to precipitate the DNA.
What should be done to plant cells before DNA extraction?
The cell walls of plant cells should be broken down by abrasion (i.e: in a blender).
What is the significance of low temperature during DNA extraction?
Low temperature should be maintained to reduce DNA breakdown.
What is semi-conservative replication?
In semi-conservative replication, the new DNA molecule comprises one parent strand and one new strand.
What enzymes are involved in DNA replication?
Enzymes include DNA helicase, DNA polymerase, and gyrase.
What does DNA helicase do?
DNA helicase unzips the DNA molecule by breaking the hydrogen bonds between complementary bases.
What is the function of DNA polymerase?
DNA polymerase forms phosphodiester bonds to join adjacent nucleotides.
What is the role of gyrase in DNA replication?
Gyrase unwinds/uncoils the DNA.
What are the components of nucleic acids?
Nucleic acids are made up of 20% nitrogen, 30% carbon, 20% oxygen, 10% hydrogen, and 20% phosphate.
In which direction do phosphodiester bonds form during DNA replication?
Phosphodiester bonds form in the same direction on each strand.
Why is DNA replication considered semiconservative?
One strand is from the original DNA and the other strand is newly formed, acting as a template.
How does the structure of DNA facilitate replication?
DNA is double stranded, each strand can act as a template, and hydrogen bonds easily break and form.
What is complementary base pairing?
Complementary base pairing allows DNA to be replicated without error, reducing mutations.
What are the components of DNA nucleotides?
DNA nucleotides consist of deoxyribose sugar, a nitrogenous base, and a phosphate group.
What are the requirements for valid centrifuge results?
Use the same concentration, volume, speed, and time for each tube.
How does DNA differ between organisms?
DNA may differ in nucleotide sequence, proportion of nucleotides, and alleles for genes.
Why is the loss of a species with unusual enzymes undesirable?
It means those enzymes can’t be applied in the future in useful ways.
How do two nucleotide chains bond together?
They bond by hydrogen bonds forming between the bases via complementary base pairing.
How does DNA structure differ from RNA structure?
RNA contains ribose instead of deoxyribose, uracil replaces thymine, and RNA is single stranded.
