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2-1 Concept Check
Nucleic Acids, DNA Replication, etc
49
Biology
Undergraduate 1
11/11/2016

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Term
DNA
Definition
the fundamental hereditary material of all living organisms. In eukaryotes, stored primarily in the cell nucleus. A nucleic acid using deoxyribose rather than ribose. DNA is a double helix made up of two antiparallel polynucleotide chains. The two chains are joined by hydrogen bonds between the nucleotide bases, which pair specifically: A with T, G with C.
Term
Nucleic acid
Definition
a polymer made up of nucleotides, specialized for the storage, transmission and expression of genetic information. DNA and RNA are nucleic acids.
Term
Nucleoside
Definition
a nucleotide without the phosphate group; a nitrogenous base attached to a sugar
Term
Nucleotide
Definition
the basic chemical unit in nucleic acids, consisting of a pentose sugar, a phosphate group and a nitrogen containing base.
Term
Nucleoside triphosphate (NTP)
Definition
is a molecule containing a nucleoside bound to three phosphate groups. It is thus one type of nucleotide.
Term
RNA
Definition
an often single stranded nucleic acid whose nucleotides use ribose rather than deoxyribose and in which the base uracil replaces thymine found in DNA Serves as genome from some viruses.
Term
Purine
Definition
one of the two types of nitrogenous bases in nucleic acids. Each of the purines, adenine and guanine pairs with a specific pyrimidine. Two fused rings.
Term
Pyrimidine
Definition
one of the two types of nitrogenous bases in nucleic acids. each of the pyrimidines (Cytosine, thymine and uracil) pairs with a specific purine. Single ring.
Term
Adenine
Definition
a nitrogen containing base found in nucelic acids, ATP, NAD and other compounds
Term
Guanine
Definition
a nitrogen containing base found in DNA, RNA and GTP
Term
cytosine
Definition
a nitrogen containing base found in DNA and RNA
Term
Thymine
Definition
nitrogen containing base found in DNA
Term
Uracil
Definition
a pyrimidine base found in nucleotides of RNA
Term
Ribose
Definition
five carbon sugar found in nucleotides and RNA
Term
deoxyribose
Definition
a five carbon sugar found in nucleotides and DNA
Term
dNTP
Definition
A deoxyribonucleotide is the monomer, or single unit, of DNA, or deoxyribonucleic acid. Each deoxyribonucleotide comprises three parts: a nitrogenous base, a deoxyribose sugar, and one phosphate group.
Term
phosphodiester linkage
Definition
the connection in a nucleic acid stand, formed by linking two nucleotides
Term
5' end
Definition
The 5′-end designates the end of the DNA or RNA strand that has the fifth carbon in the sugar-ring of the deoxyribose or ribose at its terminus.
Term
3' end
Definition
The 3′-end of a strand is so named due to it terminating at the hydroxyl group of the third carbon in the sugar-ring, and is known as the tail end.
Term
double helix
Definition
refers to DNA and the usually right handed coil configuartion of two complementary anti parallel stranfs
Term
complementary base pairing
Definition
The AT (or AU), TA (or UA), CG and GC pairing of bases in double stranded DNA, in transcription and between tRNA and mRNA.
Term
Major/minor grooves
Definition
The strand backbones are closer together on one side of the helix than on the other. The major groove occurs where the backbones are far apart, the minor groove occurs where they are close together. The grooves twist around the molecule on opposite sides. Certain proteins bind to DNA to alter its structure or to regulate transcription (copying DNA to RNA) or replication (copying DNA to DNA). It is easier for these DNA binding proteins to interact with the bases (the internal parts of the DNA molecule) on the major groove side because the backbones are not in the way.
Term
replication
Definition
the duplication of genetic material
Term
right handed
Definition
DNA is usually a right-handed helix. If you curl the fingers of your right hand and point your thumb upward the curve of the helix follows the direction of your fingers and it winds upward in the direction of your thumb
Term
transcription
Definition
the synthesis of RNA using one strand of DNA as a template
Term
translation
Definition
the synthesis of protein (polypeptide) takes place on ribosomes, using the information encoded in messenger RNA
Term
gene expression
Definition
the transcription and translation into a protein of the information (nucletoide sequence) contained in a gene
Term
genome
Definition
the complete DNA sequence for a particular organism or individual
Term
gene
Definition
a unit of heredity. used here as the unit of genetic function which carries the information for a polypeptide or RNA
Term
chargaff's rule
Definition
Chargaff's rules states that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. This pattern is found in both strands of the DNA.
Term
conservative replication
Definition
In the conservative model, the parental molecule directs synthesis of an entirely new double-stranded molecule, such that after one round of replication, one molecule is conserved as two old strands. This is repeated in the second round.
Term
semi conservative replication
Definition
In the semi-conservative model, the two parental strands separate and each makes a copy of itself. After one round of replication, the two daughter molecules each comprises one old and one new strand. Note that after two rounds, two of the DNA molecules consist only of new material, while the other two contain one old and one new strand.
Term
dispersive replication
Definition
In the dispersive model, material in the two parental strands is distributed more or less randomly between two daughter molecules. In the model shown here, old material is distributed symmetrically between the two daughters molecules. Other distributions are possible.
Term
Meselson-Stahl experiment
Definition
supported the hypothesis that DNA replication was semiconservative. In semiconservative replication, when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. It has been called "the most beautiful experiment in biology
Term
origin of replication (ori)
Definition
DNA sequence at which helicase unwinds the DNA double helix and DNA polymerase binds to initiate DNA replication
Term
replication fork
Definition
a point at which a DNA molecule is replicating. the fork forms by the unwinding of the parent molecule
Term
primer
Definition
strand of nucleic acid, usually RNA, that is the necessary starting material for the synthesis of a new DNA strand, which is synthesized from the 3' end of the primer
Term
primase
Definition
an enzyme that catalyzes the synthesis of a primer for DNA replication
Term
processive
Definition
pertaining to an enzyme that catalyzes many reactions each time it binds to a substrate, as DNA polymerase does during DNA replication
Term
template
Definition
a molecule or surface on which another molecular is synthesized in a complementary fashion, as in the replication of DNA
Term
template strand
Definition
in double stranded DNA, the strand that is transcribed to create an RNA transcript that will be processed into a protein. Also refers to a strand of RNA that is used to create a complementary RNA
Term
telomere
Definition
repeated DNA sequences at the ends of eukaryotic chromosomes
Term
telomerase
Definition
an enzyme that catalyzes the addition of telomeric sequences lost from chromosomes during DNA replication
Term
single strand binding protein
Definition
in DNA replication, a protein that binds to single strands of DNA after they have been separated from each other, keeping the two strands separate for replication
Term
sliding DNA clamp
Definition
protein complex that keeps DNA polymerase bound to DNA during replication
Term
leading strand
Definition
in DNA replication, the daughter strand that is synthesized continuously
Term
lagging strand
Definition
in DNA replication, the daughter strand that is synthesized in discontinuous stretches
Term
okazaki fragments
Definition
newly formed DNA making up the lagging strand in DNA replication. DNA ligase links Okazaki fragments together to give a continuous strand
Term
DNA helicase
Definition
an enzyme that unwinds the double helix
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