Nucleic Acids Flashcards
Nucleic Acids are polymers in which a repeating unit is
Nucleotides
True or False:
Nucleotides and nucleic acids are biological molecules that possess heterocyclic nitrogenous bases as principal components of their structure.
True
Nucleotides are important in?
- Elements of heredity and transfer of characteristics from parents to offspring.
- Energy metabolism such as Adenosine triphosphate (ATP), CTP, and GTP.
Consider the following;
DNA
Statement 1: Deoxyribonucleic Acid: Found within the cell nucleus
Statement 2: Storage and transfer of genetic information
Statement 3: Passed from one cell to another during cell division
A. One of the statements are true
B. Two of the statements are true
C. Three of the statements are true
D. None of the statements are true
C. Three of the statements are true
Consider the following:
RNA
Statement 1: Ribonucleic Acid: Occurs in all parts of a cell
Statement 2: The primary function is to synthesize the proteins
A. Statement 1 is correct while statement 2 is incorrect
B. Statement 1 is incorrect while statement 2 is correct
C. Both statements are correct
D. Both statements are incorrect
C. Both statements are correct
What are the three components of Nucleotides?
◦ Pentose Sugar: Monosaccharide
◦ Phosphate Group (PO43-)
◦ Heterocyclic Base
a —OH group present on carbon 2’ in
Ribose
a —H atom in
Deoxyribose
True or False
RNA and DNA differ in the identity of the sugar unit in their nucleotides.
True
What are the five Nitrogen-Containing Heterocyclic Bases?
- Adenine (A)
- Guanine (G),
- Cytosine (C)
- Uracil (U)
- Thymine (T)
Three pyrimidine derivatives
- Cytosine (C)
- Uracil (U)
- Thymine (T)
Two purine derivatives
- Guanine (G)
- Adenine (A)
Found in both DNA and RNA.
Adenine (A), guanine (G), and cytosine (C)
Found only in RNA
Uracil
Found only in DNA
Thymine
The pyrimidine rings;
- Cytosine (2-oxy-4-oxy pyrimidine)
- Uracil (2-oxy-4-oxy pyrimidine)
- Thymine (2-oxy-4-oxy-5 methyl pyrimidine)
The purine rings;
- Adenine (6-amino purine)
- Guanine (2-amino-6-oxy purine)
Phosphate, the third component of a nucleotide, is derived from
Phosphoric acid (H3PO4)
Under cellular pH conditions, the phosphoric acid is fully dissociated to give
Hydrogen phosphate ion (HPO42-)
The formation of a nucleotide from sugar, base, and phosphate is visualized as
Phosphate is attached to C5’ and the base is attached to the C-1’ position of pentose
Sugar-phosphate groups are referred to as nucleic acid backbone, found in?
All nucleic acids
- Sequence of nucleotides in DNA or RNA
- Primary structure is due to changes in the bases
- Phosphodiester bond at 3’ and 5’ position
- The 5’ end has free phosphate and the 3’ end has a free OH group
- Sequence of bases read from 5’ to 3’
Primary Structure
- It involves two polynucleotide chains coiled around each other in a helical fashion
- The poly nucleotides run anti-parallel (opposite directions) to each other, i.e., 5’ - 3’ and 3’ - 5
Secondary Structure
The sequence of bases on one polynucleotide is complementary to the other polynucleotide.
DNA sequence
