DNA and Replication
Which base always pairs with guanine?
Cytosine
Why is it important that the DNA be copied exactly during replication?
If not DNA may not be able to survive or may not complete the same functions (mutation)
What are the steps of the DNA ladder composed of
Nitrogen Bases
DNA can repair itself if it becomes damaged. What enzyme "snips" out the damaged portions of the molecule?
Nuclease
The beadlike structures composed of proteins and tightly wound DNA; these structures "super coil" the DNA inside the cell
Nucleosomes
What is the name of the building blocks or subunits that compose the DNA?
Nucleotides
Replication begins at various sites along the DNA molecule. These sites are called?
Origins of replication
Name given to nitrogen bases that have a 2-ring structure
Purines
Name given to nitrogen bases that have a single ring structure
Pyrimidines
The process in which DNA molecule builds an exact duplicate of itself.
Replication
A "Y" shaped region along the DNA molecule where replication is taking place.
Replication Fork
What type of bond is found between all components of the DNA molecules except the nitrogen bases?
Covalent
A small segments of DNA that contains the instructions for building a particular protein
Gene
A large amount of DNA can be packed into the small space inside the nucleus because the DNA is tightly wound around proteins called
Histones
This enzyme proofreads the growing strand of DNA. If mistakes are detected, this same enzyme removes the incorrect nucleotide and replaces it.
DNA Polymerase
Which enzymes adds new nucleotides to the newly forming strand of DNA during replication?
DNA Polymerase
What is the primary function of DNA in cells?
store information that tells the ribosomes which proteins to make and how to make them
What 3 clues about the structure of DNA did the X-Ray Crystallography photographs provide
1. DNA is double stranded 2. Strands are twisted around each other 3. Nitrogen Bases in the center
If 15% of nucleotides is guanine what r the other percentages?
15%- Cytosine 30%- Adenine 30%- Thymine
Name the type of sugar in DNA
Deoxyribose
What are the three components of a DNA nucleotide?
Deoxyribose sugar, PO4 , nitrogen base
What name is given to DNA that refers to its two-sided, spiraling shape?
Double helix
Name of the scientist whose x-ray photographs of the DNA molecule provided the clues needed to solve the structure of DNA
Franklin
The first step in DNA replication is the breaking of ____________ bonds that exists between the nitrogen bases
Hydrogen
What type of bond holds two nitrogen bases together
Hydrogen
Which molecules make up the sides of the DNA ladder
Sugar/Phosphates
If one strand of DNA has the base sequence ATGGCT, the complementary strand would contain?
TACCGA
Which base always pairs with Adenine
Thymine
Give the names of the two scientists who discovered the structure of the DNA molecule?
Watson and Crick
What does DNA stand for?
deoxyribonucleic acid
What enzyme is responsible for separating the two strands of DNA during replication?
helicase
