ATP and DNA Flashcards
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)
- Replication in diving cells (replication allows accurate copying of DNA for cell division)
- 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?
A nucleotide
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?
- 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?
DNA helicase
What bonds does DNA helicase break?
Hydrogen bonds
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?
DNA polymerase
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?
- mRNA- messenger RNA
- tRNA- transfer RNA
- 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.
What are autotrophs?
Organisms that convert light energy from the sun to chemical energy to photosynthesis
What are heterotrophs?
Organisms that cannot use the suns energy to make food
What is the cells energy source?
ATP
What does ATP stand for?
Adenine triphosphate
What is ATP?
A nucleotide
What is the structure of ATP?
Adenine bonded to a Ribose sugar bonded to 3 phosphate groups
What does ADP stand for?
Adenine diphosphate
What is the structure of ADP?
Adenine bonded to a Ribose sugar bonded to 2 phosphate groups
Where is energy stored in the cell?
In the bonds of lipid and carbohydrate molecules
What releases the energy stored in the bonds?
Breaking the bonds
What enzyme catalyses the reaction of ATP to ADP?
ATPase
How much energy does 1 mole of ATP release?
30.6 Kj
What is Phosphorylation?
The addition of one inorganic phosphate group to ADP
Why is ATP known as the universal energy currency of the cell?
This is because it is used by all living organisms, in every cell to carry energy from energy-releasing reactions to energy-consuming reactions. It is used to provide the energy for nearly all biochemical reactions in the cell.
Why is glucose not a suitable energy source? (4)
- Many enzymes are needed to release energy from glucose
- The breakdown requires many intermediates so takes a long time
- Glucose releases energy in large amounts, all at once
- Large polar molecules
Why is ATP a suitable energy source? (4)
- ATP to ADP only requires the enzyme ATPase
- ATP to ADP is a single step reaction so energy is released immediately
- ATP released small amounts of energy at a time where its needed
- Small, soluble molecules so easily transported
What are the 5 roles of ATP?
- Active Transport
- Metabolic Processes
- Movement
- Nerve Transmission
- Secretion
