DNA Flashcards
What is DNA?
DNA is the molecule that stores and encodes all the information in an organism, such as which protein to make and how to make them.
What does DNA stand for?
DNA stands for deoxyribonucleic acid. It has a double helix made up of two strands twisted together.
What are the four nucleotides of DNA?
The four nucleotides of DNA are adenine, cytosine, guanine, and thymine. A pairs with T and C with G. they are complementary to one another.
What are nucleotides?
Nucleotides are building blocks of DNA and RNA molecules that contain the cell’s genetic code.
DNA strands are held together by what?
DNA strands are held together by hydrogen bonds.
What are the five enzymes in DNA replication:
DNA Helicase, DNA Polymerase, DNA Topoisomerase, DNA Ligase, and DNA Primase
What does DNA Helicase do?
DNA helicase unwinds the DNA helix during DNA replication by breaking the hydrogen bonds.
What does DNA Primase do?
DNA primase creates a short RNA primer needed to start replication.
What does DNA Polymerase I do?
DNA polymerase I is an enzyme that removes RNA primers and replaces them with the appropriate nucleotides during DNA replication.
What does DNA polymerase III do?
DNA polymerase III is an enzyme responsible for making complementary strands of DNA during DNA replication
What does DNA ligase do?
DNA ligase is an enzyme that connects two fragments of DNA to make a single fragment.
What does DNA topoisomerase do?
DNA topoisomerase breaks (cuts/untangles) and rejoins the DNA double helix to relieve tension caused by the opening of the helix. It can heal and break bonds.
What is a lagging strand?
The lagging strand is a strand that is replicated in short fragments and away from the replication fork, during the replication of 3’ to 5’ strand.
What is a leading strand?
A leading strand is the strand that is synthesized continuously in the 5’ to 3’ direction, in the direction of the replication fork.
What are okazaki fragments?
Okazaki fragments are DNA fragments that are synthesized in short stretches on the lagging strand.
What is a chromosome?
A chromosome is the entire collection of a cell’s DNA. It contains all the cell’s genetic information.
What is DNA replication?
DNA replication is the process in which a cell’s entire DNA is copied.