Structure of DNA Flashcards
What is the full name of DNA?
Deoxyribonucleic acid
What is held inside DNA?
All the genetic information for that cell.
What is the shape of DNA?
Double-stranded helix shape (twisted ladder).
What is a nucleotide?
Subunits of DNA
What do nucleotides join together to form?
The two sides of the DNA molecule.
What do nucleotides consist of?
A phosphate group, deoxyribose sugar, and a nitrogenous base - just a base.
How many carbon atoms does the deoxyribose sugar have?
5 carbon atoms
Where are the carbons on the deoxyribose sugar with reference to the phosphate and base?
C1 is attached to the base and C4-C5 goes to the phosphate.
Where can free single nucleotides join onto the DNA?
At the 3’ end only.
What joins to thymine?
Adenine
What joins to guanine?
Cytosine
Describe the structure of the double-stranded helix.
Antiparallel
Why is the double helix antiparallel?
The nucleotides on either side of the structure run in opposite ways.
What type of bond holds together the base pairs?
Hydrogen bonds
What bonds hold together the sugar-phosphate backbone?
Sugar-phosphate bonds
What are the prime ends?
5’ end and 3’ end.
What molecule is at the 5’ end?
Phosphate
What are the two types of cells?
Prokaryotes and eukaryotes.
What type of cell possesses membrane-bound organelles (nucleus)?
Eukaryotes
What type of cell doesn’t possess membrane-bound organelles (nucleus)?
Prokaryotes
What type of cells has singular, circular chromosome and smaller circular plasmids?
Prokaryotes
What type of cells has linear chromosomes and circular chromosomes in mitochondria and chloroplasts?
Eukaryotes
What type of cell has a nucleus?
Eukaryotes
Why is yeast a special example of a type of cell, and what type is it?
Eukaryote - it is a fungal cell that sometimes contains plasmids.
Why must a strand of DNA be condensed?
To fit inside of the nucleus.
What are molecules of DNA tightly coiled and packaged around?
Histones - bundles of protein.
