Unit 1 - KA 1: Structure Of DNA Flashcards
Name the basic unit of a DNA molecule.
Nucleotide.
Describe how nucleotides are joined to form a strand of a DNA molecule.
A strong sugar phosphate covalent bond joins the 3’ carbon of one nucleotide to the 5’ carbon of the next nucleotide.
State the base pairings that form between the strands of a DNA molecule.
Adenine-Thymine
Guanine-Cytosine
Name the type of bonds that hold the strands/bases together.
Weak hydrogen bonds
State the term used to describe the structure of a DNA molecule.
Antiparallel double helix
Define the term antiparallel.
The term means the strands run in opposite directions.
Define the term prokaryote.
A prokaryotic cell is one that lacks a nucleus. Such as a bacterial cell.
Define the term eukaryote
A eukaryotic cell is one which has its DNA stored in a nucleus. Such as animal, plant and fungal cells.
Name 2 forms that double stranded DNA can take.
DNA can be linear or circular.
Describe the structure of DNA in prokaryotes.
Prokaryotic cells have a single, circular chromosome and small circular plasmids.
Describe the structure of DNA in eukaryotes.
Eukaryotic cells have linear chromosomes in the nucleus which are are tightly coiled and packaged with histones.
State which 2 organelles found in eukaryotes contain circular chromosomes.
Chloroplasts and mitochondria contain circular chromosomes.
State which eukaryotic cell may contain circular plasmids
Yeast may contain plasmids in the cytoplasm.
