Sugars & Phosphate; Structure and Superstructure Flashcards
What is the sugar component of RNA?
D-ribose
What is the sugar component of DNA?
2-deoxy-D-ribose
A compound that consists of D-ribose or 2-deoxy-D-ribose bonded to a purine and pyrimidine base by a glycosidic bond.
Nucleoside
The third component of nucleic acids.
Phosphoric acid
When this group forms a phosphate ester bond with a nucleoside, the result is a compound known as a _____________.
Nucleotide
A nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide.
Nucleotide
At which positions is phosphoric acid is esterified?
Most commonly either at the 3’ or the 5’ -OH.
Serves as a common currency into which energy gained from food is converted and stored.
Adenosine 5’ -triphosphate (ATP)
Base + Sugar
Nucleoside
Base + Sugar + Phosphate
Nucleotide
A chain of Nucleotides
Nucleic Acid
The primary structure can be DIVIDED into two (2) parts:
- The backbone of the molecule
- The bases that are the side-chain groups.
The strand is read from the?
The 5’ end to the 3’ end
ADDITIONAL INFO
The phosphodiester bond is a covalent linkage between the phosphate of one nucleotide and the hydroxyl (OH) group attached to the 3′ carbon of the deoxyribose sugar in an adjacent nucleotide, forming what is known as the “sugar-phosphate backbone” of DNA.
True or False. The base sequence is read from the 5’ end to the 3’ end.
True
Explain what is SECONDARY STRUCTURE.
Secondary Structure is the ordered arrangement of nucleic acid strands.
A type of 2° STRUCTURE in which two polynucleotide strands are coiled around each other in a SCREW-LIKE FASHION.
Double helix
In the DNA double helix, the two polynucleotide chains run in OPPOSITE DIRECTIONS which is called __________.
Antiparallel
A purine, always approximately equals the amount of a particular second base, a pyrimidine.
The bases are paired according to what rule?
Chargaff’s Rule
True or False. A-T and G-C are not complementary base pairs.
False. They are COMPLEMENTARY base pairs
DNA is coiled around proteins called __________.
Histones
Two basic amino acids whose side chains have positive charge.
Lys and Arg
What do you call the ATTRACTION between a negatively-charged DNA MOLECULES and positively-charged HISTONES?
Nucleosomes
A core of eight histone molecules around which the DNA helix is wrapped.
Nucleosome
True or False. Nucleosomes are further condensed into CHROMATIN.
True
Chromatin fibers are organized into loops, and the loops into the bands that provide the superstructure of _________.
Chromosomes.
REMEMBER!
Nucleosome to Chromatin to Chromosomes ;)
Solenoids of nucleosomes form a ______ nm filament.
30 nm
Are other substructures.
Loops and minibands
How many turns per Loop?
50 turns per loop
How many loops in miniband?
18 Loops
