DLA 1.1 DNA Structure And Analysis Flashcards
Give a brief overview of the scientific community realizing that DNA is the genetic material of heredity
Two major classes of molecules in the cell: nuclei can acid and proteins
By the end of the 1950s, much scientific evidence using bacteria, bacteriophages and radioactively labelled DNA and proteins demonstrated that nucleic acid is the genetic material
Discuss DNA being mutated by UV light
- DNA can be mutated if exposed to UV light at 260 nm
- Cataracts and cancer are caused
—Scurntusts used this to study bacteria and yeast
Discuss early scientists differentiating DNA and proteins
Both are colorless
-early scientists could be distinguish DNA from protein using a sample in a cuvette in a spectrophotometer and the correct wavelength of ultraviolet light
Discuss the difference in absorption of UV light between DNA and proteins
Nucleic acid absorbs UV light at 260nm and protein absorbs UV light at 280 nm
What are Mendel’s unit factors?
Now called genes
List the 4 criteria for genetic Material
- Replication
- Storage information
- Expression of information
- Variation by mutation
What is Replication?
Genetic material duplicates and then partitions into two daughter cells
What is storage of information ? (Criteria or genetic material )
- Genetic material is a repository of information that may or may not be expressed in the cell
- A chemical language for the survival of the cell
What is the expression of information criteria of genetic information?
- A cell needs to turn genes on and turn genes off
- Depends on the needs of the cell at any given time
Explain the Variation by mutation of genetic material criteria of genetic material
-A change in the chemical composition of the DNA that affects the expressed product of DNA
Assess the similarities and differences of a Nycoeic acids of RNA and DNA
- Both consist of nitrogenous bases with a pentose sugar to form a nucleotide
- Both Nucleosides join with phosphate groups to form a nucleotide
- Nucleotides join together to form polynucleotides through phosphate groups
- DNA uses thymine whereas Uracil is used by RNA
What are pyrimidines?
Pyrimidine rings are 6-membered single ring
Give 3 examples of pyrimidines
Cytosine and thymine and uracil
What are purines?
Purine rings are 9 membered rings(6 membered rings with five membered rings attached)
Give 2 examples of purines
Pure as gold- guanine and adenine
How is uracil chemically different to thymine?
Thymine has a methyl group at carbon -5 while uracil has an H
Where does the pentose sugar accept the nitrogenous base?
Carbon q
How can ribose and deoxyribose sugar be differentiated?
C2’: If it has OH here it is called ribose and for RNA
If it has H instead of OH, it’s called “deoxyribose” and used for DNA
Which carbons in the pentose sugar are used to make bonds for polynucleotides?
C3 and C5
What kind of bond forms between ribose/deoxyribose and nitrogenous bases?
A glycosidic bond
List the ribonucieosides
Adenosine
Cytidine
Guanosine
Uridine
List the deoxyribonucleosides
Deoxyadenosine
Deoxycytidine
Deixyguanosine
Deoxythymidine
What is a nucleotide?
When at least one(up to 3) phosphate groups are connected to the 5’ Carbon of the pentose sugar
What is the importance to phosphate groups in making DNA and RNA?
They store energy to help drive the synthesis of DNA and RNA
-form the structural backbone of DNA and RNA
Why are nucleoside triphosphates important to forking DNA and RNA?
- Have large amounts of energy due to delocalised electrons that is released when you break bonds between the groups
- This energy is used to drive the synthesis reaction, making polynucleotides