Intro to DNA Flashcards
What are the four types of nitrogenous bases? How do they pair together?
Adenine—>Thymine.
Cytosine—> Guanine.
What are the three structures that make up a DNA strand?
A nitrogenous base, deoxyribose sugar, and a phosphate group.
What type of bond connects the nitrogenous bases together?
A hydrogen bond.
What type of bond connects the detoxified and the phosphate group together?
A covalent bond.
How many hydrogen bonds connect adenine and thymine together?
2 hydrogen bonds.
How many hydrogen bonds connect guanine and cytosine together.
3 hydrogen bonds.
What does 5’ connect to and what does 3’ connect to?
5’ connects the 5th carbon atom to the phosphate group, and the 3’ connects the 3rd carbon atom to the hydroxyl group.
DNA molecules run ____ from one another.
antiparallel.
How many chromosomes does each human have per cell?
46 chromosomes, 23 pairs.
What role do chromosomes play in DNA?
Chromosomes condense your DNA to split your cell into two.
What is mitosis?
A replication when one cell duplicates into two cells.
What connects the deoxyribose sugars together?
A phosphate group
What makes N15 different from N14?
N15 has an extra proton and is heavier compared to N14.
Where do N15 and N14 come from?
Comes from E. coli bacteria.
What happens to the DNA when it makes a copy of itself.
When the heavy DNA makes a copy of itself, it gets lighter.
What are the three methods of DNA replication? Which method is correct?
The three methods are semi-conservative, conservative, and dispersive. Semi-conservative is correct.
What are the three steps to the semi-conservative process?
- Start with a parent molecule.
- Two complementary strands serve as templates.
- Two DNA molecules, one “old” strand, one “new” strand. Both are identical to the parent molecule.
How long does DNA replication take?
Can replicate in just a few hours.
How does the leading strand copy?
The leading strand copies continuously towards the replication fork 5’ to 3’.
How does the lagging parent template copy?
The lagging parent template runs 5’ to 3’ towards the replication fork.
What is the first step of the DNA replication process?
The enzyme Helicase breaks H bonds between the Nitrogenous bases.
New strands are extended at the replication fork in both directions.
What is the second step of the DNA replication process?
Primase works to identify the location of the gene where DNA polymerase is to replicate.
DNA Polymerase helps to attach the new nucleotides as they align with their base pair in the 5’ to 3’ direction.
What is the third step of the DNA replication process?
Lagging strands (Okazaki fragments) extend in pieces away from the replication fork. The enzyme, DNA ligase attaches the fragments on the lagging strand into one piece.
What are histones?
Protein molecules whose DNA is tightly coiled.
What are the four enzymes used for DNA replication?
Primase, Ligase, DNA polymerase, and helicase.
