Biological Molecules - Nucleotides Flashcards
(16 cards)
list the components of nucleotides
list 3
they all have -
- a 5-carbon sugar
- a nitrogenous base
- a phosphate group
give examples of nucleotides.
- What is the most important one.
DNA, RNA, ATP
- ATP is the most important one.
describe the basic structure of ATP
list 3
- 3 phosphate groups
- a ribose molecule
- adenine base
how is ATP formed.
when ADP - adenosine disphosphate reacts with an inorganic phosphate.
- this reaction is endergonic - meaning energy is inputed for the reaction to take place.
where does the energy needed to make ATP come from
from exergonic reaction - like cell respiration. they release energy.
what is the use of ATP
It’s also known as the bodies universal energy currency.
- when ATP is hydrolysed to ADP and an inroganic phophate 30.6 KJ/mol energy is released.
what is a hydrolysis reaction
when a water molecule is used to break down a bond in a substance.
describe the structure of DNA
made up of 2 polynucleotide chains that are anti-parrallel to each other.
the nucleotides are held together by phophodiester bonds.
complementary bases are held together by hydrogen bonding which holds the two strands together in a double helix shape.
describe the bases in DNA - the 2 categories and how they pair up including number of bonds between each.
Adenosine, Guanine, Cytosine and Thymine.
Purines - A G - double ring structure
Pyrimidines - T C - single ring structure
the bases that pair up -
A T = 2 hydrogen bonds
C G = 3 hydrogen bonds
What is RNA. describe the structure
They are single polynucleotide strands. with a ribose sugar. they have 4 different bases - adenine, guanine, cytosine and uracil.
list the 3 main types of RNA
mRNA, tRNA, rRNA
What is mRNA, describe it’s structure
it is a single strand of RNA, wound into a helix. which is complementary to DNA.
describe the function of mRNA
it carries genetic code (complemenary to the DNA) to the ribosome
describe the struture of rRNA
it is made up of 2 subunits, 1 small and 1 large.
describe the function of rRNA
it makes up ribosomes as well as taking part in protein synthesis.
describe the structure and function of tRNA
Has an amino acid binding site on one end and an anticodon on the other end, which is complementary to the codon on the mRNA sequence.
(codon and anticodon are both trinucleotides - made up of 3 nuleotides.
