Chapter I: Nucleic Acid Structure and Organization Flashcards
Transcription.
process of DNA going to RNA
Translation
process of RNA being made into protein
Transcription occurs in what phase of the cell cycle?
throughout interphase
What part of the cell does transcription take place?
nucleus
What phase of the cell cycle does DNA replication occur?
During S phase
Where does translation of RNA occur? What phase?
in the cytoplasm; throughout the cell cycle
Describe M phase of the cell cycle.
mitosis the time in which the cell divides to form 2 daughter cells
Interphase?
the time between 2 cell divisions or mitosis
What is interphase divided into?
G1, S, G2 phase
G1 phase? (another name for it)
(gap 1)
period of cellular growth preceding DNA synthesis
G0 phase? Examples?
cells that have stopped cycling, such as muscle and nerve cells are said to be in a special state called G0
S phase
DNA synthesis; when DNA replication occurs
G2 phase? Another name for it?
gap 2
period of cellular growth after DNA synthesis but preceding mitosis; replicated DNA is checked for any errors before cell division
Reverse transcription?
produces DNA copies of RNA and more commonly associated with life cycles of retroviruses, which replicate and express their genome through a DNA intermediate (an integrated provirus)
What are the 2 types of nucleic acids?
DNA and RNA
What are DNA and RNA assembled from?
What are the 3 components?
nucleotides, which consist of 3 components:
a nitrogenous base, a 5-carbon sugar (pentose), and phosphate
Difference beween nucleic acids and nucleotides?
nucleic acids are polymers of nucleotides
What are some purines?
Pure As Gold
adenine
guanine
Some other purine metabolites not usually found in nucleic acids:
xanthine, hypoxanthine, and uric acid
Pyramidines names?
cytosine, uracil, thymine
Difference between adenine and guanine structure?
adenine has amino group at the top
Difference between cytosine uracil and thymine structure?
cytosine has amino group at the top
uracil and thymine have the same structure but thymine has a methyl group on the side
How do you tell the difference between naming a structure with the prefix deoxy?
on the pentose sugar if there is no OH on the right side (2’) position
Suffix for naming most nucleosides?
“sine” (for purines) or “dine” (for pyrimidines)
adenosine
guanosine
cytidine
uridine
thymidine
Is the DNA double helix usually right or left handed? Also what is another name for the most commonly found type of DNA?
right handed (B- DNA)
How does Daunorubicin and doxorubicin exert their effects? What is daunorubicin and doxorubicin often used for?
anti-tumor drugs that are used in treatment of leukemias
exert their effects by intercalating between the bases of DNA, thereby interfering with the activity of topoisomerase II and preventing proper replication of DNA
Hybridization?
when probe DNA binds to target DNA sequences of sufficient complementarity
Negatively supercoiled DNA?
formed if DNA is wound more loosley than in Watson-crick DNA. (required for most biologic reactions)
Positively supercoiled DNA?
formed in DNA is wound more tightly than in Watson Crick DNA
Topoisomerases
enzyme that can change the amount of supercoiling in DNA molecules.
They make transient breaks in DNA strands by alternately breaking and resealing sugar-phosphate backbone
Histones are rich in what amino acids?
arginine and lysine
Lysine and arginine are both (positively or negatively charged) amino acids?
positively charged
What comprises the histone octomer?
2 copies of each histones:
H2A
H2B
H3,
H4
10 nm chromatin
Whe DNA is wound around outside of the histone octamer to form a nucleosome (a series of nucleosomes called “beads on a string”
30 nm fiber?
When histone H1 is associated with the linker DNA found between nucleosomes to help package them a solenoid-like structure is formed which is referred to as 30 nm DNA
Euchromatin
chromatin that is more open and available for gene expression
Heterochromatin
chromatin more highly condensed and associated with areas of chromosomes that are not expressed
Does heterochromatin typically correspond to (10 nm or 30 nm fibers)?
30 nm fibers
