nucleic acids Flashcards
what is a nucleic acid?
nucleic acids are large polymers of nucleotides. basically they are the bigger thing like dna or rna. nucleotides make up nucleic acids.
Formally - Nucleic acids are biological molecules, DNA and RNA, carrying genetic information in cells through sequences of nucleotides, vital for inheritance and protein synthesis.
what are polymers?
Polymers are like building blocks that repeat and connect to create long chains. They’re used in things like plastics, and in living things like DNA. They are large molecules composed of smaller molecules called monomers linked together in a chain-like fashion.
what are nucleotides made up of?
Nucleotides are made up of a pentose sugar, nitrogenous base and phosphate group that join together by a condensation reaction to form a polymer.
what is a condensation reaction?
In DNA formation, condensation reactions join nucleotides. During this process, a phosphate group and a sugar molecule link, releasing a water molecule. This covalent bond formation repeats to create the DNA double helix structure.
Basically it’s the removal of water then a phosphate group and a sugar molecule join together through a covalent bond.
what is a purine, what are the types?
Purines are adenine and guanine, they have 2 rings in their structure. - they are larger than pyrimidines.
what are pyrimidines, what are the types?
Pyrimidines are thymine, cytosine, and uracil. They contain only 1 ring in their structure and they are smaller than purines.
Describe the formation of the sugar-phosphate backbone by nucleotide polymerisation in DNA and RNA.
Nucleotide polymerization in DNA and RNA involves linking nucleotides through condensation reactions. The phosphate group of one nucleotide attaches to the sugar of the next, forming a covalent bond. The resulting sugar-phosphate backbone has a 5’ to 3’ directionality and provides structural support.
Basically the phosphate grp of one nucleotide at the 5’C end attaches to the sugar of another nucleotide at the 3’C end to crate a sugar phosphate backbone.
what is a phosphodiester bond?
phosphodiester bond is the linkage between the 3’ carbon atom of one sugar molecule and the 5’ carbon atom of another
what is nucleotide polymerization?
Nucleotides polymerize/connect by chemically linking a phosphate group at the 5′ position of one nucleotide to the hydroxyl group at the 3′ position of the next nucleotide - thus creating a covalent bon between them.
Why does only RNA have uracil?
Stability– Because of structural differences, uracil is less stable than thymine and more susceptible to mutations.
Explain the complementary pairing in a double-strand structure of DNA.
In a double-strand structure of DNA, complementary pairing is the specific binding of nitrogenous bases between the two DNA strands.
Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C), forming hydrogen bonds.
Explain the importance of complementary base pairing in allowing genetic information to be replicated and expressed.
This base pairing forms hydrogen bonds, and ensures genetic code fidelity (less mistakes) and stability in DNA replication and transcription.
complementary base pairing in DNA is fundamental for maintaining the accuracy of genetic information during replication and for enabling the expression of this information when creating proteins, which are essential for all cellular processes.
