Nucleotide Structure Flashcards
Nucleotide =______________+______________+ ______________
Nucleotide = nitrogenous base + pentose sugar + phosphate
This refers to the combination of nitrogenous base & pentose sugar
Nucleoside
This serves as the bond between the 5’-OH of pentose sugar and phosphoryl group.
Ester bond: Phosphodiester Bond
True or False. DNA-protein interaction is via hydrophobic interaction only.
False. DNA -protein interaction is via hydrophobic interaction & ionic bonding.
This rule states that the number of purines = Number of pyrimidines.
Chargaff’s Rule
Identify the most abundant chromatin protein.
Histones
This type of DNA is the most common form physiologically.
B-DNA
Which histone is seen in the linker region?
H1
Differentiate Euchromatin versus Heterochromatin.
Euchromatin:
1. Less condensed
2. Transcriptionally active
3. Stains less densely
Heterochromatin:
1. Highly condensed
2. Transcriptionally inactive
2. Stains densely
This is the most heterogenous RNA.
mRNA
This is the most abundant RNA, about 80% of total RNA.
rRNA
What are the unusual bases tRNA?
- Dihydrouridine
- Pseudouridine
- Inosine
- Ribothymidine
What is the production of an RNA copy from a DNA strand called?
Transcription
What activator is responsible for transcription which functions to add one ribonucleotide at a time to an elongating RNA strand?
Polymerase
What are the types of non- protein coding RNA?
- rRNA
2.IncRNA
3.tRNA
4.snRNA
5.miRNA
6.siRNA
(MISS TR)
Which type of non-coding RNA play a significant role in diabetes mellitus?
IncRNA
Name the 3 stop codons that terminate translation
- UAA
- UGA
- UAG
The poisonous mushroom Amanita Phalloides (death cap) contains the peptide a-amnitin which inhibits ___________?
RNA Polymerase II
Which antibiotic binds to the B subunit of bacterial DNA-dependent RNA Polymerase
Rifampicin
__________ is purine to purine & pyrimidine to pyrimidine
Transition
_________% of cellular DNA is in mitochondria.
0.01%
Which DNA is described as left-handed helix with 12 base pairs per turn?
Z-DNA
This is the adapter molecules that translate the nucleotide sequence of mRNA into specific amino acids.
Transfer RNA
Which RNA is involved in rRNA and mRNA processing and gene regulation?
Small Nuclear RNA
Which maintain the separation of the parent strands?
Single- stranded DNA binding proteins
These are RNA molecules that have the ability to catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes.
Ribozymes
True or False. G-C bonding is stronger than A-T bonding.
True. 3H bonds vs 2H bonds. The higher the G-C content of a DNA, the higher the melting temperature of DNA.
DNA is wrapped _______ times over a histone octamer in left-handed helix.
1.75 times
Identify the number of base pairs per turns in a Z-DNA.
12 base pairs
Name the two types of grooves of the DNA.
Major & Minor grooves
Levels of DNA organization that consists of nucleosomes separated by a linker DNA.
10nm chromatin fibril
True or False. Nucleic acids are negatively charged at physiologic pH.
True
Levels of DNA organization also known as “solenoid”.
30 nm chromatin fibril
Characteristics of the genetic code where a certain codon codes, always codes for the same amino acid.
Non-ambiguous / Specific
Characteristics of a genetic code where codon always code for the same amino acid from generation to generation and between species.
Universal
What characteristics of a genetic code where a given amino acid may have more than one triple codon coding for it.
Redundant / Degenerate
What characteristics of a genetic code where DNA is read from a starting point as a continuous sequence of bases , taken three at a time without any gaps?
Non-overlapping / Commaless
What are the (7) Nitrogenous bases ?
Guanine
Adenine
Thymine
Uracil
Cytosine
Xanthine
Hypoxanthine
Enumerate (6) Nucleosides ?
Guanosine
Adenosine
Thymidine
Cytidine
Uridine
Inosine
Nucleoside = base + Sugar
Enumerate (4) Nucleotides?
ATP
GMP
UDO
cAMP
Nucleotides = base + sugar + phosphate
