DNA Structure Analysis Questions
Answered
1.
2.
3.
4.
5.
6.
The twisted ladder structure of DNA is called a Double
Helix.
The backbone of DNA is made up of deoxyribose sugar
and phosphate group.
The ladder-like rungs of DNA are made up of nitrogenous
bases.
Adenine always pairs up with Thymine.
Cytosine always pairs up with Guanine.
A nucleotide is the basic building block of DNA. A
nucleotide is made up of one deoxyribose sugar, one
phosphate group, and one nitrogenous base.
DNA Replication
p. 46
DNA Packaging
• A cell’s nucleus contains chromosomes
made up of DNA.
Chromatin
Fibers
Each chromatin
fiber is a tightly
wound supercoil
Each super coil is
made up of coils. A
coil is a chain of
beadlike structures
called nucleosomes
Each nucleosome
consists of DNA wound
around histones
DNA replication
• Before a cell divides, it duplicates its DNA
in a copying process called replication
• this process insures that each resulting
cell receives a complete set of DNA
molecules
• During replication, the
DNA molecule separates
into two strands, then
produces two new
complementary strands
following the rules of
base pairing. Each
strand of the double helix
of DNA serves as a
template for a new strand
DNA Replication
• In Eukaryotic Cells
replication occurs in
hundreds of places at
once
• Replication proceeds
in both directions until
each chromosome is
completely copied
• The places where
separation and
replication occur are
called replication
forks
Creating a New Strand
• Two strands of the double helix separate
allowing two replication forks to form
• Each new strand forms following the rules of
base pairing. For example:
The original strand has the bases:
TACGTT
What would the complementary strand be?
ATGCAA
• The result is two DNA molecules identical to
each other and to the original
• NOTE: each DNA molecule will have one
original strand and one new strand.
• More practice. Create the complementary
strand
CCGTACTTACG
Answer
GGCATGAATGC
How Replication Occurs
• DNA replication is carried out by a series
of Enzymes
• The enzymes “unzip” a molecule of DNA
by breaking the hydrogen bonds between
the base pairs
• DNA polymerase joins individual
nucleotides to produce a DNA molecule
and proofreads each new DNA strand
Placed on the same page as your
notes
Glue the picture of DNA
replication into your notes.
Copy diagram 1 into your
notes. The diagram shows
one side of a strand of
DNA. Create the
complementary strand of
DNA that would be made
by the process of
replication.
A
T
T
G
A
C
G
A
C
Diagram 1
On page 45 of your spiral…
Word
Double Helix
Nucleotide
Nitrogen Base
Replication
Transcription
Codon
Translation
Anticodon
Ribosome
Amino Acid
Protein
Definition in own words
Picture