DNA Structure & Replication Flashcards
What 3 structures are the DNA Monomers composed of?
- Phosphate
- Nitrogen Base
- Deoxyribose Sugar
What structure does DNA arrange itself in?
Double Helix
Which structure is dependent on the type of nucleotide?
Nitrogen Base
What are the 4 types of nitrogen bases that make up nucleotides?
- Guanine
- Cytosine
- Thymine
- Adenine
How do the nucleotides in DNA pair with one another?
Guanine —> Cytosine
Thymine —> Adenine
Which 2 nitrogen bases are known as Purines?
Adenine & Guanine
Which 2 nitrogen bases are known as Pyramidines?
Cytosine & Thymine
What does DNA do?
DNA is the cell’s instructions for making proteins
What are the structures in DNA called?
Chromosomes
What do chromosomes contain?
Genes
Genes
Areas that have the code for a specific protein
Whom discovered the structure of DNA?
James Watson & Francis Crick
What bond connects nucleotides in base pairs?
Hydrogen Bond
Who discovered DNA?
Rosalind Franklin
DNA Helicase
A protein enzyme that opens up DNA exposing the nitrogen bases of the nucleotides
DNA Polymerase
A protein enzyme that adds new base pairs to the opened DNA strands
Steps to DNA Replication
- DNA Helicase unwinds and opens the DNA Molecule
- DNA Polymerase adds new bases on to each DNA strand and checks for errors
- Two identical DNA molecules are produced
Why is the DNA Replication Process known as “semi-conservative”?
Half of each strand is old, half is new
Why do cells need to replicate their DNA?
- Growth of multi-cellular organisms
- Reproduction
- Repair of injury
- Replacement of old cells
What is transcription?
A step in which DNA is turned into messenger RNA
Which organelles make proteins?
Rough ER
Why does the location of these 2 organelles in a cell make the transcription of mRNA necessary?
The nucleus sends instructions to Rough ER & sends it to ribosomes to make proteins
Why do cells need to perform DNA replication before a cell goes through cell division?
So the cells that divide have the same DNA as the original cell
