Molecules of Life Flashcards
What are nucleic acids?
They are polymers made up of nucleotides
What is the difference between DNA and RNA?
Sugar - DNA had deoxyribose and RNA has ribose
What is a nucleoside
A nucleotide lacking a phosphate
What are the pyrimidines?
Cytosine, thymidine, uracil
What are purines?
Adenine and guanine
What type of linkage is the glycosidic bond?
It is always Beta
What is the ester linkage between nucleotides?
Phosphodiester bond
How many hydrogen bonds are present between A and T?
2
How many hydrogen bonds are present between C and G?
3
What three steps is DNA replicated by?
Initiation
Elongation
Termination
Describe DNA replication.
- Unwinding the DNA
- Process is carried out by DNA Helicase which break the hydrogen bonds
- The parent strands act as a template for the synthesis of a new DNA strand
- New DNA strands are complementary to the parent strands
- DNA synthesis is catalysed by DNA polymerase
What are the precursors for the synthesis of new DNA strands?
Nucleoside triphosphates
How does RNA differ structurally from DNA?
- Sugar
- Thymine replaced by uracil in RNA
- RNA is single stranded
What is a gene?
A DNA segment that contains the information necessary for the synthesis of one protein
What is the template strand?
This is the complementary strand