1.1 - Structure Of DNA Flashcards
(18 cards)
Where is Genetic Information found?
Genetic information in every living cell is contained within deoxyribonucleic acid (DNA).
Explain he structure of DNA
It is a double-stranded, ladder-shaped molecule, twisted in one direction to form a double helix shape.
What is the DNA molecule comprised of?
The DNA molecule is comprised of two chains of nucleotides joined by hydrogen bonds between the bases.
What does a DNA nucleotide look like?
A phosphate connecting to a deoxyribose sugar to a base
What is a polynucleotide?
A chain of nucleotides which make up one strand of DNA
What are the four complementary base pairs?
Adenine and Thymine, Guanine and Cytosine
DNA is a double-stranded anti-parallel structure, explain what this means
So each strand of DNA runs in the opposite direction to the other – it is parallel but upside down to the other strand.
What are the two nucleotide srands held together by between the bases?
Weak hydrogen bonds that can be broken easily
What causes DNA to have the double helix shape?
The way that the hydrogen bonds form between the bases forces the two strands of nucleotides to twist into a double helix shape.
What two types can organisms be divided into?
Prokaryotes and Eukaryotes.
Do prokaryotes have a distinct membrane bound nucleus?
No, prokaryotes do not have a distinct membrane bound nucleus.
Do eukaryotes have a distinct membrane bound nucleus?
Yes, eukaryotes do have a distinct membrane bound nucleus.
Give an example of a prokaryote.
Bacteria.
Give 5 examples of eukaryotes.
Animals, plants, fungi, protists, yeast
Describe where prokaryotes store their DNA.
Prokaryotes usually have a single circular double stranded chromosome. Some of the DNA is in the form of tiny rings called plasmids.
Describe where eukaryotes store their DNA.
The chromosome is linear and contained in a membrane-bound nucleus. But the mitochondria and chloroplasts contain tiny pieces of circular DNA.
Can eukaryotes contain plasmids?
Yes, some yeast cells do.
What is it called when the DNA is tightly wound and packaged round proteins?
Histones.
