1.1 STRUCTURE OF DNA FLASHCARDS
QUESTION
1
What does DNA store and what
does this determine?
2
What is a DNA molecule
composed of?
3
4
5
6
7
8
9
10
11
12
13
14
15
16
What are the 4 bases?
How many types of nucleotides
are there and why?
Where does a chemical bond
form?
ANSWER
Genetic information in its sequence of bases
which determines the genetic code and structure
of its proteins
Two strands composed of repeating units called
nucleotides composed of deoxyribose sugars,
phosphates and bases
Adenine A, Thymine T, Guanine G, Cytosine C
Four as there are four bases
Between the phosphate group of one nucleotide
and the C3 of the deoxyribose of another
nucleotide to produce a sugar-phosphate
backbone for each strand
What bonds the bases of both
Weak hydrogen bonds
strands?
Which end are nucleotides added
C3 end
for the DNA strand to grow?
The DNA strand on the left has
the 3C growing end at the
bottom and its 5C at the top. The
strand on the right is the reverse A double stranded antiparallel structure
of this which results in the two
strands running in opposite
directions. What does this form?
Both strands form a twisted coil for the base
Why does a double helix form?
pairs to align with each other
Single-celled organisms without a nucleus such
What are prokaryotes?
as bacteria and archaeans
How is DNA organised in
In circular chromosomes in the cytoplasm
prokaryotes?
In circular plasmids in the cytoplasm
What are eukaryotes?
Organisms that have cells with a nucleus
Where are eukaryotes mainly
In multicellular plants and animals
found?
In linear chromosomes in the nucleus
How is DNA organised in
In circular chromosomes in the mitochondria and
eukaryotes?
chloroplasts
It is tightly coiled and packaged with associated
How does DNA fit into linear
proteins called histones that help to keep the
chromosomes in the nucleus?
DNA strands untangled
In linear chromosomes in the nucleus
How is DNA organised in
In circular chromosomes in the mitochondria
eukaryotic yeast cells?
In circular plasmids in the cytoplasm of some
yeast species