CHAPTER IV: THE GENETIC MATERIAL (MODULE) Flashcards
The size of the DNA polymer varies with the complexity of
the organism; more complex organisms tend to have _______
DNAs
larger
Nucleoproteins are found in?
Cytoplasm particularly in the ribosomes
Has a very acidic property which gives nucleic acids their acidity
Phosphate (from phosphoric acid)
The 2 strands of the DNA structure is ________– each
has an opposite polarity to the other
antiparallel
Purines are composed of?
Adenine and Guanine
__________ is a polymeric substance made up of four nucleotides
(A, G, C, T).
DNA
Nitrogenous bases are connected by ___________.
H bonds
The other strand is formed in short segments (Okazaki fragments) in the 3’ to 5’ direction. The segments are joined together by DNA ligase
step 4 in DNA replication
Knowledge of the___________ and function of ___________ is essential in understanding genetics and many aspects of disease, pathophysiology, as well as the genetic basis of the disease
Structure
Nucleic acids
RNA is ___________, thus it does not contain equal amounts of specific bases
single stranded
What are the stop codons?
UAA, UAG, UGA
Stores all the information about the proteins that make-up the organism (genetic material)
DNA
Properties of Nucleoproteins:
1. ________
2. Soluble in _____ with which they form salts.
3. Precipitated from solutions by _______ but redissolved by dilute _____
4. Not _______by heat
5. Exhibit similar __________ and color reactions with proteins
Soluble
alkalies
acetic acid; HCl
coagulated
precipitation
What are the functions of Nucleoproteins?
- Duplication
- Storage, expression and transmission of genetic information
DNA: ____________
Chargaff’s rule
is the biochemical process by which DNA molecules produce exact duplicates of themselves
DNA Replication
TRUE OR FALSE:
Each time the cell divides, an exact copy of the DNA of the parent cell is needed for the new daughter cell
TRUE
DNA segment that codes for the biosynthesis of specific protein
Gene
groups of 3 adjacent bases that specify an amino acid
Codons/Coding triplet
Three Stages of Protein Synthesis:
- Transcription
- Translation
- Formation of Polypeptide chain
nucleoside joined with a phosphate group (Sugar + base)
Nucleotide
_________ are variable and stick out from the backbone
Nitrogenous bases
nitrogen base combined with 5-carbon sugar (Sugar + base + PO4);
Nucleoside
The base composition of the DNA of all organisms ____________
CONSTANT
The 2 strands are held together by __________________
complementary base pairing
The first __________are more significant and important.
2 bases
short segments of the DNA molecule
Okazaki fragments
The double helix is held together
by ______________extending
from the base on one strand of
the double helix to a complementary base on the other strand.
hydrogen bonds
serves as the backbone of
its structure
Ribose-PO4
The enzyme DNA helicase causes the two strands to unwind, producing two separate strands
step 1 in DNA replication
The structure of the DNA has been likened to a ladder that is twisted into a double helix, with the rungs of the ladder kept ________ to the twisted railings
perpendicular
Macromolecules which were first discovered in the nuclei of cells, which contain all the information to
direct the activities of a cell and its reproduction
Nucleic acids
____________ is the predominant conformation
Double helix
The _________ is variable and sensitive to mutation
3rd base
causes the DNA helix to unwind
DNA helicase
These are proteins conjugated with a nucleic acid (as a DNA) and is the principal constituent of the hereditary material in chromosomes
Nucleoproteins
The structure of DNA, according
to Watson and Crick, consists of
______________ of nucleotides in the form of a _____________, with both nucleotide strands coiled around the same axis.
two polymeric strands
double helix
The RNA is much ___________ than the DNA
smaller
What is the importance of nucleoproteins?
they are closely associated with chromosomes
fundamental sub-unit
of nucleic acids
Nucleoside
TRUE OF FALSE:
The amount of purine bases is always unequal to the amount of pyrimidine bases
FALSE
What are the secondary structure of RNA?
hairpins, step-loop structure
RNA: Functions
o Serves as the ___________ of genetic information to the site of protein synthesis (mRNA)
o Essential __________ of the ribosomes
o Serves as the ________ for some viruses
carrier
components
genetic material
The four bases are __________in their ring structures.
flat
Amount and # of Nucleotides of tRNA?
5%
75
Amount and # of Nucleotides of mRNA?
15%
1200
DNA polymerase joins the newly attached nucleotides to create one continuous strand in the 5’ to
3’ direction
step 3 in DNA replication
The other strand is formed in short segments (Okazaki fragments) in the _______ direction. The segments are joined together by DNA ligase
3’ to 5’
DNA ligase
A 5-carbon sugar (ribose or deoxyribose)
Sugar (pentose)
Joins Okazaki fragments together
DNA ligase
The phosphate and deoxyribose units ______________along the two railings of the ladder, and two
nitrogen bases form each rung of the ladder
alternate
Amount and # of Nucleotides of rRNA?
80%
1800
Free nucleotides pair with their complementary base on the template strands by means of
hydrogen bonds
step 2 in DNA replication
What are the TERTIARY structure of RNA?
pseudoknot, cloverleaf structure
The ____________component of the DNA is located on the side of the ladder
sugar-PO4
DNA polymerase joins the newly attached nucleotides to create one continuous strand in the ____ to
___ direction
5’
3’
It is the start codon
AUG
Describes the flow of genetic information from DNA to RNA to Proteins
The Central Dogma of Molecular Biology
catalyzes the formation of a new phosphodiester linkage between the nucleotide and the growing strand
DNA polymerase
Pyrimidines are composed of?
Cytosine, Uracil, Thymine
