are biological molecules that participate in nearly all biochemical interactions and form the monomers of nucleic acids. they are molecules consisting of a five-carbon sugar, a phosphate group and a nitrogenous base
1 of 20
what is the role of nucleotides
they become phosphorylated nucleotides when they contain more than one phosphate group, they help to regulate metabolic pathways and can be components of many coenzymes
2 of 20
what is a nucleic acid
it is an important class of macromolecules found in all cells and viruses. For example DNA and RNA
3 of 20
what is the structure of DNA
it is a polymer, consists of two polynucleotides, the strands go in an antiparallel direction, each nucleotide consists of a phosphate group a deoxyribose and a nitrogenous base, and a phosphodiester bond between the sugar residue and the phosphate group
4 of 20
what is the difference between purines and pyrimidines
a purine is a two-ringed nitrogenous base, and a pyrimidine is a one ringed base
5 of 20
what is the importance of hydrogen bonds
the antiparallel DNA strands are joined together by hydrogen bonds. Adenine pairs with thymine with two hydrogen bonds and guanine pairs with cytosine with three hydrogens bonds and purines pair with pyrimidines and hydrogen bonds allow molecules to unzip
6 of 20
why does DNA have an anti-parallel structure
the opposite directions two strands refer to the direction that the third and fifth carbon molecule on the deoxyribose sugar the 5' end of the molecule is where the phosphate group is attached to the fifth carbon atom of the deoxyribose and the 3' is on t
7 of 20
how does DNA differ in Eukaryotic and Prokaryotic cells
majority of the DNA content or the genome is in the nucleus. Each DNA is tightly wound around a histone protein. There is also a loop of DNA without histone proteins inside mitochondria and chloroplasts. In prokaryotic cells the DNA is in a loop free in t
8 of 20
what is semi-conservative replication
This is how DNA replicates, resulting in two new molecules, each of which contains one old strand and one new strand. One old strand is conserved in each new molecule.
9 of 20
how does mutation occur
mutations occur when the wrong nucleotides are inserted, it is estimated to occur in 1 in 10^8 base pairs. However during the replication process there are enzymes that can proofread and edit out such incorrect nucleotides.
10 of 20
what is RNA
sugar molecule win each nucleotide is ribose and the nitrogenous base is uracil which replaces thymine and is a pyrimidine and the polynucleotide chain is usually single-stranded
11 of 20
how does the structure of RNA differ from DNA
RNA is single-stranded whilst DNA is double-stranded. RNA contains uracil whilst DNA has thymine. RNA has the sugar ribose which has an extra hydroxyl group whilst DNA has the sugar deoxyribose. RNA can have multiple structures, and is read by ribosomes w
12 of 20
what is the nature of the genetic code
the genetic code is near universal, the genetic code is degenerate and the genetic code is non-overlapping
13 of 20
how are proteins made - what are the different steps
Transcription and translation
14 of 20
what are the three forms of RNA
messenger RNA, transfer RNA and ribosomal RNA
15 of 20
what is a gene
a length of DNA that codes for a polypeptide or for a length of RNA that is involved in regulation gene expression
16 of 20
what is an anticodon
a triplet base of tRNA molecule, complementary to the mRNA codon
17 of 20
what is a base triplet
a triplet of bases on a DNA molecule
18 of 20
what is a codon
a triplet base on a length of mRNA
19 of 20
what is the functions of polypeptides
the shape of active site of an enzyme molecule must be complementary to the shape of the substrate molecule. Antibody has to have a shape complementary and receptors on a cell membrane must have a complementary to the shape of the cell-signalling molecul
20 of 20
Other cards in this set
Card 2
Front
what is the role of nucleotides
Back
they become phosphorylated nucleotides when they contain more than one phosphate group, they help to regulate metabolic pathways and can be components of many coenzymes
Card 3
Front
what is a nucleic acid
Back
Card 4
Front
what is the structure of DNA
Back
Card 5
Front
what is the difference between purines and pyrimidines
Comments
No comments have yet been made