Enzyme Function
History
Structure of DNA
Replication
Repair
100
What is the function of DNA Helicase?
Helicase untwists the double helix and separates the template DNA strands at the replication fork.
100
This scientist coined the phenomenon transformation, a phenomenon now defined as a change in genotype and phenotype due to the assimilation of external DNA by a cell.
Frederick Griffith
100
What are the three components of nucleotides?
- Nitrogenous base
- Pentose sugar
- phosphate group
100
What is the function of the single-strand binding proteins?
Single-strand binding proteins keep the unpaired template strands apart during replication.
100
_______ proofreads each new nucleotide against the template nucleotide as soon as it is added. If there is an incorrect pairing, this enzyme removes the wrong nucleotide and then resumes synthesis.
DNA polymerase
200
What is the function of primase?
Primase can start an RNA chain from a single RNA nucleotide, adding RNA nucleotides one at a time, using the parental DNA strand as a template. Serves as a guide for DNA polymerase III.
200
This bacteriologist tried to identify the transforming substance in Griffith's experiment, focusing on three main candidates: DNA, RNA, and protein.
Oswald Avery
200
What pentose sugar makes up a nucleotide?
Deoxyribose
200
The ________ strand requires only one primer and elongates continuously.
The ________ strand is synthesized as a series of short segments called Okazaki fragments.
leading; lagging
200
This enzyme cuts out a segment of a damaged strand, and the resulting gap is filled in with nucleotides, using the undamaged strand as a template.
Nuclease
300
What is the function of DNA polymerase III?
DNA polymerases catalyze the synthesis of new DNA by adding nucleotides to a preexisting chain. Can catalyze on in the 5' --> 3' direction, building off the pentose sugar.
300
To determine the source of genetic material in the phage, _______ and _______ designed an experiment in which they could label protein and DNA and then track which entered the E. coli cell during infection.
Alfred Hershey and Martha Chase
300
What is the name of the sugar-phosphate backbone of DNA?
phosphodiester backbone
300
What are the strands of DNA on the lagging strand that are about 1000 to 2000 nucleotides long?
Okazaki fragments
300
DNA replication error rate is only one mistake per 10 _______ nucleotides.
billion
400
What is the function of DNA ligase?
DNA ligase eventually joins the sugar-phosphate backbones of the Okazaki fragments to form a single DNA strand.
400
_________ _____ are a series of rules based on a survey of DNA composition in organisms. These rules show a peculiar regularity in the ratios of nucleotide bases.
Chargaff's rules
400
How do the DNA strands run?
Antiparallel
400
The leading strand copies continuously toward the _______ _______.
Replication fork
400
When two ______ are mistakenly paired together, it creates a "bump" in the DNA strand.
purines
500
What is the function of DNA polymerase I?
DNA polymerase I replaces the RNA nucleotides of the primers with DNA versions, adding them one by one to the 3’ end of the adjacent Okazaki fragment.
500
These scientists shook the scientific world with an elegant double-helical model for the structure of deoxyribonucleic acid, or DNA.
James Watson and Francis Crick
500
How do the nitrogenous bases complement each other?
Pyrimidine binds to a purine (A&T, C&G).
500
This model of DNA replication, suggested by Watson and Crick, predicts that when a double helix replicates, each of the daughter molecules has one old strand and one newly made strand.
Semi-conservative model
500
________ are the ends of eukaryotic chromosomal DNA molecules and do not contain genes.
Telomeres