Happy Thursday….
Turn in the DNA homework sheet from Tuesday if
you did not finish it in class.
Bellwork: Explain the steps of the DNA
replication process. You must use all of the
words below.
Double Helix, unzip, helicase, DNA
polymerase, complementary, nucleotides,
semi-conservative
Test tomorrow…
Review sheet
Notes
Power Points
Extra Credit
Open your Journal to page 38. Title that
page Test Review.
Number your page 1-25 (leave space)
DNA: Structure
and Replication
Hallway Practice
1. What would the
complementary strand of the DNA
molecule shown below look like?
1. What would the
complementary strand of the DNA
molecule shown below look like?
T A AG C C C T A T A A
2. Scientists
compared the
DNA in four
mammals
shown to the
right. Based on
the table, which
two mammals
are most closely
related to each
other?
Mammal
DNA Sequence
1
TCTCAACTACAA
2
TCTCAGCTGCAA
3
ACTCAGCTACAA
4
TCTCAGCTGCAG
2. Scientists
compared the
DNA in four
mammals
shown to the
right. Based on
the table, which
two mammals
are most closely
related to each
other?
Mammal
DNA Sequence
1
TCTCAACTACAA
2
TCTCAGCTGCAA
3
ACTCAGCTACAA
4
TCTCAGCTGCAG
3.-4. In a sample of doublestranded DNA, 30% of the
nitrogenous bases are thymine.
What percentage of the
nitrogenous bases in the sample
are adenine? What percentage
are guanine (in the same sample)?
3.-4. In a sample of doublestranded DNA, 30% of the
nitrogenous bases are thymine.
What percentage of the
nitrogenous bases in the sample
are adenine? What percentage
are guanine (in the same sample)?
If 30% is Thymine then 30% must be Adenine (base pairing rule).
The total percent of A and T would equal 60% (30% A + 30% T = 60%)
That leaves 40% total for C and G. We know they have to be equal so we
split 40% in half (base pairing rule).
The percentage for C must be 20% and the percentage for G therefore
must be 20%. 
5. A single nucleotide of DNA is composed of which of the following
substances?
A.
adenine, guanine, and cytosine
B.
hydrogen, a phosphate group, and
adenine
C.
ribose sugar, deoxyribose sugar,
and thymine
D.
deoxyribose sugar, a phosphate
group, and a nitrogenous base
5. A single nucleotide of DNA is composed of which of the following
substances?
A.
adenine, guanine, and cytosine
B.
hydrogen, a phosphate group, and
adenine
C.
ribose sugar, deoxyribose sugar,
and thymine
D.
deoxyribose sugar, a phosphate
group, and a nitrogenous base
6. Which of the following statements
describes each new molecule of DNA
produced when DNA replicates?
A.
Each new molecule is half the length of the original molecule.
B.
Each new molecule has only the coding portions of the original
molecule in its sequence.
C.
Each new molecule contains one strand from the original molecule
and one newly synthesized strand.
D.
Each new molecule retains the A, C, and G bases in the DNA
sequence but replaces the T base with U
6. Which of the following statements
describes each new molecule of DNA
produced when DNA replicates?
A.
Each new molecule is half the length of the original molecule.
B.
Each new molecule has only the coding portions of the original
molecule in its sequence.
C.
Each new molecule contains one strand from the original molecule
and one newly synthesized strand.
D.
Each new molecule retains the A, C, and G bases in the DNA
sequence but replaces the T base with U
7-9. Identify the part of DNA
indicated by the arrow.
C
7
8
9
7-9. Identify the part of DNA
indicated by the arrow.
C
7
Deoxyribose
Sugar
8
Hydrogen
Bonds
9
Nitrogenous
Base
10. For each statement below,
indicate the biomolecule that is
being described. (carbohydrate,
lipid, protein, nucleic acid)
A.
B.
C.
D.
Store and transmit genetic information
Main component of the cell membrane
Speeding up biochemical reactions (catalyst)
Polysaccharide broken down for energy
10. For each statement below,
indicate the biomolecule that is
being described. (carbohydrate,
lipid, protein, nucleic acid)
A.
B.
C.
D.
Store and transmit genetic information (Nucleic Acid)
Main component of the cell membrane (Lipid)
Speeding up biochemical reactions (catalyst) (Protein/enzyme)
Polysaccharide broken down for energy (Carbohydrate)
11. Which of the following
models most accurately represents
the structure of DNA? Explain why.
A
B
C
D
11. Which of the following
models most accurately represents
the structure of DNA? Explain why.
A
Sugar Phosphate
Backbone, Antiparallel.
Bases properly paired
in the middle
B
Incorrect:
bases on
outside
C
Incorrect:
Single strand
instead of
double
D
Incorrect: shows
two phosphates
instead of one in
backbone.
12-14. Identify the structure indicated
by the arrows below
12
13
14
12-14. Identify the structure indicated
by the arrows below
12
Sugar Phosphate
Backbone
13
Nucleotide
14
Nitrogenous Bases
15. Copy and complete the
chart below
Monomer
Polymer
Carbohydrate
Fatty Acid
Protein
Nucleotide
15. Copy and complete the
chart below
Monomer
Monosaccharide
Fatty Acid
Amino Acid
Nucleotide
Polymer
Carbohydrate
Lipid
Protein
Nucleic Acid
16. What information about DNA
was discovered from the picture
below?
16. What information about DNA
was discovered from the picture
below?
This famous picture from Rosalind Franklin was the important
because it gave the first real evidence for the double helix
STRUCTURE of DNA
17. The graph below shows how
the activity of an enzyme changes
over a range of pH values. What is
the optimum pH for this enzyme
to function in?
17. The graph below shows how
the activity of an enzyme changes
over a range of pH values. What is
the optimum pH for this enzyme
to function in?
Optimum means
“best”.
The Enzyme works
“best” at a pH of
6.6
18. Indicate whether the following
statements are true or false.
A. Enzymes are recycled after each use, and can be used over and
over again.
B. Enzymes reduce the activation energy required for chemical
reactions.
C. Enzymes fit with multiple types of substrates.
D. Enzymes are specific and fit with only one type of substrate.
18. Indicate whether the following
statements are true or false.
A. Enzymes are recycled after each use, and can be used over and
over again. T
B. Enzymes reduce the activation energy required for chemical
reactions. T
C. Enzymes fit with multiple types of substrates. F
D. Enzymes are specific and fit with only one type of substrate. T
19. Explain what biological
process is occurring in the picture
below.
19. Explain what biological
process is occurring in the picture
below.
This is a picture of
the DNA
replication
process
20. A ring is analogous to a
carbohydrate, just as a twisted ladder
is analogous to ________.
20. A ring is analogous to a
carbohydrate, just as a twisted ladder
is analogous to _DNA_______.
*Analogous means “similar to”
21. Describe the function of both
helicase and DNA polymerase as
enzymes in DNA replication.
21. Describe the function of both
helicase and DNA polymerase as
enzymes in DNA replication.
Helicase: unzips the double helix structure of DNA
DNA Polymerase: assembles the new complementary
strand onto the original strand
22. Why is DNA referred to as the
common genetic code? **Hint:
What information is carried in the
DNA molecule?**
22. Why is DNA referred to as the
common genetic code? **Hint:
What information is carried in the
DNA molecule?**
All living things have DNA and the exact same four Nitrogenous
Bases (ATCG). The sequence of the bases determines the “code”
for that organism.
23. Which of the following
features in DNA is most important
in determining the traits of an
organism?
A.
the direction of the helical twist
B.
the number of deoxyribose sugars
C.
the sequence of nitrogenous bases
D.
the strength of the hydrogen bonds
23. Which of the following
features in DNA is most important
in determining the traits of an
organism?
A.
the direction of the helical twist
B.
the number of deoxyribose sugars
C.
the sequence of nitrogenous bases
D.
the strength of the hydrogen bonds
24. The statements below describe
the function of an enzyme in the
body. Which statement is true?
A. The enzyme increases the amount of time the light is visible.
B. The enzyme decreases the amount of energy required for the
reaction to start.
C. The enzyme increases the number of sites on the substrate that
must bind to oxygen.
D.The enzyme decreases the temperature of the environment
inside the body.
24. The statements below describe
the function of an enzyme in the
body. Which statement is true?
A. The enzyme increases the amount of time the light is visible.
B. The enzyme decreases the amount of energy required for the
reaction to start.
C. The enzyme increases the number of sites on the substrate that
must bind to oxygen.
D.The enzyme decreases the temperature of the environment
inside the body.
25. Enzymes usually end in the
letters _____, while carbohydrates
usually end in the letters _____.
25. Enzymes usually end in the
letters _ase_, while carbohydrates
usually end in the letters _ose_.