DNA Flashcards
Double Helix
Twisted ladder shape of DNA formed by two nucleotide strands twisted around each other
Nucleotides
The subunits of nucleic acids that consists of 5 carbon sugars, a phosphate group and one of the 4 nitrogenous bases
Structure of DNA (+ letters)
Made of 3 parts…a phosphate group, a sugar (deoxyribose) group , and one of the 4 types of nitrogen bases
ADENINE (A) = THYMINE (T)
CYTOSINE (C) = GUANINE (G)
Orientation of DNA (Anti-parallel)
5’-3’ direction one strand is oriented in the 5’-3’ direction and the complimentary strand is 3’-5’ direction
What sugar group is in the structure of DNA?
deoxyribose
DNA and RNA are which type of macromolecule?
Nucleus acids
Macromolecules involved in replication and protein synthesis
Carbs (sugar), nucleic acids, and proteins for synthesis
Replication involved nucleic acids
What is semiconservative replication?
Each new DNA molecule consists of one new strand and one old strand
What is the first step of unwinding in DNA replication
1) DNA helicase - an enzyme - unwinds and unzips the double helix
What is the second step of unwinding in DNA replication
An enzyme breaks the hydrogen bonds between the base pairs and double helix unzips leaving single strands of DNA
What is the third step of unwinding in DNA replication?
Protein (called single stranded binding protein) keeps the strands separate - on each DNA strand
What is base pairing in DNA replication
Considered the second stage of DNA replication:
Consists of pairing bases
What is the first step of base pairing
The enzyme DNA polymerase catalyzes synthesis of new DNA molecules
adenine always pairs with…thymine
cytosine always pairs with…guanine
what is the second step of base pairing
DNA accurately replicates itself DNA is transferred into RNA and is translated from RNA into amino acids
What is the third step of base pairing
The DNA strands are separate during replication as each parent strand serves as a template for new strands
What is transcription
Information coded in cells DNA instructs the cell to make messenger RNA molecules from a nucleotide
What is translation
What a codon from mRNA forms an amino acid
Begins with start codon and ends with stop
What is Okazaki Fragments
Short segments of DNA synthesized discontinuously in small segments in the 3’ to 5’ direction by DNA polymerase
DNA is ________ as well as ________
semi-discontinuous, semiconservative
What is Joining?
The third part of DNA replication
When DNA polymerase comes to a RNA primer on the DNA and removes the primer and fills it in the place with nucleotides
What happens at the end of joining
DNA Lucas’s links into 2 sections
What does semi discontinuous mean
Because of the lagging strand; template DNA and polymerase on one strand repeatedly separate, reposition, join together to resume replication of lagging strand.
What is semi continuous
Strands are being formed continuously - independently
Enzymes
a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction
