Topic 1- Nucleic Acids and ATP Flashcards
Describe the structure of a nucleotide.
Made up of a pentose sugar, a nitrogen-containing base and a phosphate group.
How is a polynucleotide formed?
A polynucleotide is formed when two nucleotides join together by a condensation reaction between the phosphate group of one nucleotide and the sugar of another.
The chain of phosphates and sugars is known as the sugar-phosphate backbone.
What is the bond formed between two nucleotides?
A phosphodiester bond via a condensation reaction.
What is DNA?
DNA (Deoxyribonucleic acid) is a molecule found in all organisms. It holds all the genetic information.
What is the structure of each DNA nucleotide?
Each DNA nucleotide consists of a deoxyribose sugar, a nitrogen-containing organic base and a phosphate group.
There are four possible bases - adenine (A), thymine (T), cytosine (C), and guanine
(G).
What is the structure of a DNA molecule?
A DNA molecule is twisted into a double helix composed of two separate strands of polynucleotides joined together by a hydrogen bonds between complementary bases.
What are the 4 possible bases that can be found in a DNA molecule and which bases are complementary to each other?
Adenine pairs with thymine and guanine pairs with cytosine. through complementary base pairing.
How does the structure of the DNA lead to their properties?
The double stranded feature helps DNA to become more stable and act as template in semi-conservative replication.
The coiled feature helps the DNA to be more compact.
The complementary base pairing ensures semi-conservative replication to occur as the hydrogen bonds between the bases are weak and can easily be broken during semi-conservative replication.
Describe the process of DNA replication.
- The enzyme DNA helicase breaks the hydrogen bonds between the base pairs on the two polynucleotide DNA strands. This unwinds the helix to form two single
strands. - Each original single strand acts as a template for the new strand. Complementary base pairing means that free-floating DNA nucleotides are attracted to their base pair - A with T, and C with G.
- Condensation reactions join the nucleotides of the new strands together using the enzyme DNA polymerase as the catalyst. Hydrogen bonds form between bases on the original and new strands.
- Each new DNA molecule contains one strand from the original DNA molecule and one new strand.
What is RNA?
RNA (Ribonucleic acid) is a molecule found in all organisms. It transfers genetic information from the DNA to the ribosomes.
There are two types of RNA and they are called mRNA (messenger RNA) and tRNA (transfer RNA).
What is the structure of each RNA nucleotide?
Each RNA nucleotide consists of a ribose sugar, an organic base and a phosphate group.
What is the structure of a RNA molecule.
An RNA molecule is relatively short and it is single stranded.
What are the 4 possible bases that can be found in a RNA molecule and which bases are complementary to each other?
The possible bases are adenine, guanine, cytosine and uracil.
Adenine pairs with uracil and guanine pairs with cytosine through complementary base pairing.
What is ATP?
ATP (Adenosine triphosphate) is an energy carrier molecule that delivers energy for life processes.
What is the structure of ATP?
ATP is made from 1 adenine base, 3 phosphates and a ribose sugar.
