Lesson 1 - Nucleotides and ATP Flashcards
What is a nucleotide
molecules with 3 parts - a pentose sugar, a nitrogenous base and a phosphate group - joined by condensation reactions
what are the functions of nucleotides
- provide an energy currency in the form of ATP
- provide the building blocks for the mechanisms of inheritance in the form of RNA and DNA
state the difference between RNA and DNA
- the pentose sugar in RNA is ribose, and in DNA is deoxyribose
- DNA is double stranded whilst RNA is single stranded
- DNA contains the bases A, G, T and C, whilst RNA contains the bases A, G, U and C
- RNA is shorter and less stable than DNA
what do the most common nucleotides have
purine base or a pyrimidine base
compare the purine base with the pyrimidine base
the purine base has 2 nitrogen-containing rings, and the pyrimidine base has 1 nitrogen-containing base. They are both weak bases
Give 2 examples of purines
- Adenine (A)
- Guanine (G)
give 3 examples of pyrimidines
- Cytosine (C)
- Thymine (T)
- Uracil (U)
what is the result of having a phosphate group in a nucleotide
nucleotide is an acidic molecule and carry a negative charge
how is a nucleotide formed
the sugar, base and phosphate group are joined together by condensation reaction, with the elimination of 2 water molecules
what is ATP
a nucleotide that acts as the universal energy supply molecule in cells. It is made up of the base adenine, the pentose sugar ribose and 3 phosphate groups
what is Adenine
a purine base found in RNA and DNA
what is Guanine
a purine base found in RNA and DNA
what is Cytosine
a pyrimidine base found in DNA and RNA
what is Thymine
a pyrimidine base found in DNA
what is Uracil
a pyrimidine base found in RNA
what is ATPase
an enzyme that catalyses the formation and the breakdown of ATP, depending on conditions
what is ADP
a nucleotide formed when ATP loses a phosphate group and provides energy to drive reactions in the cell
what is a redox reaction
reactions in which one reactant loses electrons (is oxidised) and another gains electrons (is reduced)
when energy is needed in a cell, what happens?
the 3rd phosphate bond in ATP is broken in a hydrolysis reaction, catalysed by ATPase. The products are ADP, another nucleotide, and a free inorganic phosphate group, this releases energy
how is energy lost when ATP is split
by heat
how is the energy produced used
for energy-requiring biological activity e.g. active transport, nerve impulses & muscle contraction
what type of reaction is the breakdown of ATP into ADP
reversible reaction
what does ATP stand for
Adenosine Triphosphate
what does ADP stand for
Adenosine Diphosphate
