Topic 5- Nucleic Acids Flashcards
(52 cards)
What is a nucleotide
The basic unit from which nucleic acids are formed. They are a combination of a phosphate a pentose sugar and an organic nitrogenous base
What are the three components that make up a nucleotide
A phosphate group
A pentose sugar
And an organic nitrogenous base
How do the components of a nucleotide come together
Via two condensation reactions with the removal of a water molecule
Condensation to join the phosphate group to the pentode sugar and a condensation joining the pentode sugar and the organic nitrogenous base - forming a Single nucleotide
Where do the condensation reactions occur in the formation of a nucleotide
A condensation reaction between the phosphate group r and the pentose sugar and a condensation reaction between the pentose sugar and the nitrogenous base
What are nucleic acids
Polymers made up of many units of monomers called nucleotides
What does ATP stand for
Adenosine-tri-phosphate
What is ATP known as
The universe energy of currency
Describe the three advantages of ATP for its function as the universal source of energy
It’s soluble so diffuses easily across the cell membrane and hence can be transported around the cell easily
It is an immediate source of energy as only one type of enzyme is needed to hydrolyse it
And it realises energy in a useable amount that are matched closely to the energy required in a couple reaction
Name cellular activities requiring ATP
Active transport
Protein synthesis
Nerve transmission
Muscle contraction
What is the structure of ATP
Phosphorylated RNA nucleotide composed of a nitrogenous base adenine joined to a ribose sugar and three phosphate groups
What are the two types of nucleic acid
Deoxyribosenucleic acid
And ribonucleic acid
What are the pyramidine bases
Cytosine uracil thymine
What are the purine bases
Adenine and guanine
What are the pyrimidine bases in DNA
Thymine and cytosine
What are the pyrimidine bases in RNA
Uracil and thymine
What structure is pyrimidine bases
Single ring structure
What is the structure of a purine base
Double ring structure
Describe the structure of DNA
Millions of nucleotides linked together to form a long chain called a polynucleotide. These two polynucleotide chains wind together to form a double helix
How is a polynucleotide formed
When the nucleotide join together via condensation reactions between the deoxyribose sugar and the phosphate group the deoxyribose of one sugar forms a bond via a condensation reaction with the phosphate group of another nucleotide to forms a sugar phosphate backbone
In a polynucleotide strand where do the bases attach
The bases attach to the sugar phosphate backbone
How is the double helix of DNA formed
The two polynucleotides are wound together and held by hydrogen bonds between the nitrogenous bases
How are the two polynucleotides held together
Hydrogen bonds between pairs of nitrogenous bases
Why is complimentary base pairing important
It ensures the DNA replicates correctly
It ensures the same proportion of A and T is in a DNA molecule and the same proportion of G and C
It ensures the polynucleotide strands are anti parallel to each other
How many hydrogen bonds are there between G and C
3 hydrogen bonds
