Flashcards in ATP and DNA Deck (46)
What are Exons?
Regions of DNA that codes for proteins
What are Introns?
Non coding blocks of nucleotides repeated to cause genetic variation
What type of genes have introns?
Eukaryotic Genes (discontinuous genes)
What type of genes have no introns?
Prokaryotic Genes (continuous genes)
What is the difference between DNA and RNA?
DNA consists of Adenine, THYMINE, Guanine and Cytosine
RNA consists of Adenine, URACIL, Guanine and Cytosine
What is the function of DNA? (2)
1.Replication in diving cells (replication allows accurate copying of DNA for cell division)
2.Carries the genetic information for proteins synthesis
What is DNA?
Large molecules made of several nucleotides
What is a pryrimidine?
A single ring of carbon and nitrogen consisting of Cytosine and Thymine
What is a purine?
A double ring of carbon and nitrogen consisting of Guanine and Adenine
What is the monomer of DNA?
What is the structure of DNA?
Phosphate group bonded to deoxyribose bonded to Nitrogenous base
What is DNA replication?
When the DNA is coped and 2 of each molecules is present in the nucleus
Why does DNA replication take place?
The DNA needs to double in quantity before cell division by mitosis or meiosis
When does DNA replication take place?
During the interphase stage of cell division
Where does DNA replication take place?
In the nucleus
What is the first stage to DNA replication?
1. One end of the DNA unwinds due to DNA helicase, this is a replication fork. The DNA helicase attaches to one end of the DNA and travels along the molecules. It unwinds the double helix and breaks the Hydrogen bonds between the complementary base pairs (unzipping)
What enzyme 'unzips' the DNA?
What bonds does DNA helicase break?
What happens to the DNA during replication after it has been unzipped?
Free DNA nucleotides bind to their complementary base of the template strand and hydrogen bonds form between A=T and C=G. The enzyme DNA polymerase joins the new nucleotides together by the formation of phosphodiester bonds, to produce a new sugar- phosphate backbone.
What enzyme catalyses the condensation of the new nucleotides?
Why does only one side of the unzipped DNA bond with nucleotides?
The DNA polymerase enzyme only works in one direction
How does the direction of the strand effect the replication process? How is this overcome?
On one side the enzyme can travel the entire way (from 3' to 5'). On the other strand the enzyme has to male small sections at a time and these sections have to be joined together by the enzyme DNA ligase
What are the three types of RNA?
1.mRNA- messenger RNA
2.tRNA- transfer RNA
3.rRNA- Ribosomal RNA
What is the structure of mRNA?
Messenger NA (mRNA) is a long single stranded molecules formed into a helix
What is the structure of rRNA?
Ribosomal RNA (rRNA) is a long large, complex molecules made up of both double and single helices.
What is the structure of tRNA?
Transfer RNA (tRNA) is a small single stranded molecule which forms a clover leaf shape. One end contains the bases CCA- this is where the acid attaches. At the opposite end of the molecule there is a series of 3 bases called the anticodon.
What is the function of mRNA?
Manufactured in the nucleus and carries the genetic code from the DNA in the nucleus to the ribosome
What is the function of rRNA?
Ribosomes are made up of rRNA and protein
What is the function of tRNA?
tRNA molecules bring amino acids to the ribosome so that proteins can be synthesised.