NUCLEIC ACID Flashcards
BUILDING BLOCKS OF NUCLEIC ACID
nucleotides
what are the 4 nitrogenous bases of DNA?
adenine, guanine, thymine, cytosine
what machine was used to confirm the SHAPE OF THE DNA MOLECULE as double helix?
x-ray crystallography
who were the first scientist to determine the 3D STRUCTURE OF DNA?
james watson and francis crick
is common in the CYTOPLASM OF A CELL
RNA
ACTS AS MESSENGER, carrying information from the DNA towards cytoplasm where proteins are synthesized
RNA
this proposed flow of genetic information from DNA TO RNA TO PROTEIN is the basis of what we now called
central dogma
it ACTS AS AN ADAPTOR
transfer RNA
is a procedure used to ISOLATE DNA FROM THE NUCLEUS OF CELLS
DNA extraction
it is usually performed to OBTAIN A RELATIVELY PURE FORM OF DNA that can be used for further investigations
DNA extraction
INCREASES THE SURFACE AREA for the extraction process. The larger the surface area, the faster the extraction procedure
mashing
membrane lipids are REMOVED IN THE SAMPLE by adding a DETERGENT
lysis of cells
it helps the DNA strands to STICK TO EACH OTHER, it also causes proteins and carbohydrates to PRECIPITATE
addition of saline solution
DNA is INSOLUBLE IN ALCOHOLS, usually with ethanol or isopropanol. Draws water molecule away from DNA, causing it to collapse and precipitate
addition of cold alcohol
the isolated DNA appears like a WHITE MUCUS
isolate the DNA from the solution
are either PHYSICAL OR CHEMICAL AGENT that permanently changes genetic material, usually the DNA
mutagens
is a CHANGE IN A SINGLE NUCLEOTIDE BASE on the m-RNA chain
point mutation
NO CHANGE IN AMINO ACID SEQUENCE specified by codons
silent mutation
CHANGE IN AMINO ACID SEQUENCE specified by codons
missense
SHORTENED AMINO ACID SEQUENCE due to substitution causing a stop codon to form somewhere in the mRNA
nonsense mutation
ADDITION/DELETION of nucleotide resulting in codon frameshift
frameshift mutation
INVOLVE LARGE REGIONS OF CHROMOSOMES and can be divided into four categories; deletion, duplication, inversion, and translocation
chromosomal mutation
DNA is found in the
cytoplasm of prokaryotic
cells
PROKARYOTIC DNA
DNA is found in the nucleus
of the cell
EUKARYOTIC DNA
cut the phosphodiester
backbone of one strand of DNA
Class I topoisomerases
cut both strands of DNA,
pass some of the remaining DNA helix
Class II topoisomerase
Enzymes that are involved in changing
the supercoiled state of DNA.
TOPOISOMERASE
is a bacterial topoisomerase that
introduces negative supercoils into DNA.
DNA gyrase
a complex of DNA and protein found in
eukaryotic nuclei
chromatin
basic proteins found complexed to
eukaryotic DNA
histones
a globular structure in chromatin in which
DNA is wrapped around an aggregate of histone
molecules
nucleosome
is an individual DNA molecule bound to a group of proteins.
chromosomes
are strands of DNA in a double helix with base pairing such that each
base is located opposite its complementary base.
Complementary DNA strands
Purine and pyrimidine bases are what in nature?
hydrophobic
ANTICANCER DRUGS THAT INHIBITS DNA SYNTHESIS
ANTIMETABOLITES
formed directly by DNA transcription
Heterogenous nuclear RNA
facilitates the conversion of heterogeneous nuclear RNA
Small nuclear RNA
carries instructions for protein synthesis
Messenger RNA
combines with specific proteins to form ribosomes
Ribosomal RNA
delivers amino acids to the sites for protein synthesis
Transfer RNA
delivers amino acids to the sites for protein synthesis
Transfer RNA
is the process by which DNA directs the synthesis of hnRNA/mRNA molecules
Transcription
is a segment of a DNA strand that contains the base sequence for the production of a specific hnRNA/mRNA molecule.
gene
all of the genetic material (the total DNA) contained in the
chromosomes of an organism.
genome
unwinding of DNA double
helix done by______ not by DNA helicase
RNA polymerase
is the process by which mRNA codons are deciphered
translation