Download Chapter 11: DNA: The Molecule of Heredity

#: ___ Scientist’s Name: _______________________
Competency 5 – Analyze the roles DNA & RNA play
on the mechanism of inheritance.
c. Explain & distinguish among the roles of DNA & RNA in
replication, transcription, & translation.
Biology Textbook ~ Chapter 12: Molecular Genetics
DaBook ~ Section 12
DNA





Means…
Is a type of _________________
What ________ & ___________ are made
of
Made up of repeating ___________ subunits
1 nucleotide looks like the illustration to the
left – label it
2 strands so bases can pair up
o A binds ___ only
o C binds ___ only
Strand 1
Strand 2
P
S
P
T
P
S
Phosphates + sugars
on the outside
4 types (nitrogen bases):
1–
234-
S
P
G
Remember
DNA is like an Oreo
S
Bases on the inside
(Bases fit like
puzzle pieces)
Phophates + sugars = cookies
Bases = cream filling
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

Shape is a ______________: 2 spirals wound around each other
______________________ took an X-ray photo of DNA; died
from cancer due to experiments with DNA; she discovered the
sides of the helix, but not the rungs; ______________ &
_________________ interpreted the photo and discovered the
double helix structure (They won the Nobel Prize). She received
no credit.
Codon: Group of ___ bases

Genes:
o The code is the order of the _______ (letters)
o Genes are hundreds or thousands of _________ long
Eye color gene
Dimples gene
Hair color gene
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Chargaff’s Rule
 In DNA, the amount of ___ = the amount of T
the amount of ___ = the amount of G
DNA is complementary
 Complementary:

Example: Strand 1- ATG GGC CTA
Strand 2- TAC CCG GAT
Replication



Happens when ____________________________ before
mitosis and meiosis
Semiconservative replication:
Original DNA
DNA unzips
Each original strand
grows a new strand
o DNA never ever leaves the nucleus
o DNA is the master copy of the directions a cell needs to live so it
needs to be protected
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But DNA in
the cytoplasm
can be
destroyed
DNA in
the
nucleus is
safe
RNA
means…
 You can always make more RNA so it’s ok if it gets destroyed
(You can’t make more DNA!!!)
DNA
RNA
How many
?
?
strands?

Nucleotide
subunit
Phosphate
Group
Nitrogen
Base
?
_____________ sugar
Bases
Phosphate
Group
Nitrogen
Base
?
____________ sugar
T–
U–
G–
G–
Transcription


Definition:
The type of RNA made is called ___________________ because
it sends a message from DNA to the cytoplasm
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DNA safe in the
nucleus
Uses mRNA
To send a
message to the
cytoplasm
Transcription
1.
2.
3.
4.
DNA: GAG AAC TAG TAC
RNA: CUC UUG AUC AUG
For figuring out RNA:
A binds __
C binds __
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DNA
mRNA
mRNA
Cytoplasm
of cell
Nucleus
___________
happens in the
nucleus. An
RNA copy of a
gene is made.
Then the _____
that has been
made moves out
of the nucleus
into the
cytoplasm
Once in the
cytoplasm, the
_______ is used
to make a
protein
How does mRNA tell the cell what to do?
 mRNA is a message that codes for a ______ (made in the
cytoplasm and then work to keep the cell alive)
 Translation (protein synthesis): ____________________
 Proteins are made up of ____________ (small building blocks)
 There are ___ different types of amino acids
Protein
Amino Acids
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Nucleus
Translation
1. ________ moves
out of nucleus and
into cytoplasm
Cytoplasm
2. mRNA attaches
to a ________
3. ______________
decodes the mRNA
and brings amino acids
to build up the protein
Ribosome
tRNA
____
__________ (3 bases
on tRNA): Matches up
to codons on mRNA
4. ________ (chain of
amino acids) detaches
from ribosome and goes
off to work in the cell
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Genetic Code

Code that matches _______ in mRNA to ___________ on tRNAs
mRNA
codons
(3 bases)
Amino
acids
Stop codon – codes for the
end of the mRNA (no amino
acid added)
1. Read your mRNA codon 
ACU
2. Find 1st base on the left, 2nd base on the top, 3rd base on the right.
Find where they all cross in the chart.
3. Read your amino acid.

Threonine
Different codons code for different amino acids!!!
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Central dogma of molecular biology
___________
_
____
Directions to
make proteins are
safely stored in
the nucleus
___________
____
Carries the
directions to
the cytoplasm
_______
Work to keep
the cell alive
DNA is made of repeating units called _______________.
Label the two types of nucleotides based on rings.
How do some cells become brain cells and others become skin cells, when the
DNA in ALL the cells is exactly the same?
Why is the DNA molecule referred to as the "blueprint of life"?
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DNA, RNA, and PROTEINS
MATCH THE PROCESS WITH ITS DESCRIPTION:
TRANSLATION
TRANSCRIPTION
REPLICATION
_______________________ Making a complementary RNA sequence from a DNA code (DNA  RNA)
_______________________ Making a DNA copy of a DNA molecule (DNA  DNA)
_______________________ Making proteins from an RNA message (RNA  protein)
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Use words from the word bank to match the following:
messenger-RNA
transfer-RNA
ribosomal-RNA
___________________ Carries the DNA code from nucleus to cytoplasm
___________________ Made by the nucleolus
___________________ Adds the correct amino acid to the growing protein chain
___________________ Combines with proteins to form ribosomes
___________________ Has a CODON region
___________________ Has an ANTICODON region
___________________
___________________
___________________
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COMPARE AND CONTRAST
CHROMATIN
CHROMOSOMES
DNA
RNA
What are DNA/proteins doing?
Type of cell seen in?
COMPARE AND CONTRAST
Double / Single stranded?
Sugar used?
List all nitrogen bases it has
Which nitrogen base is missing?
Location in cell?
Name the 3 parts of a nucleotide molecule:
__________________
_____________________
_____________________
If a double helix is compared to a “twisted ladder”, which would the following
represent?
Sides of the ladder ? ___________________________
Rungs of ladder ? ______________________________
Glue in the middle that holds the ladder together? ____________
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DNA, RNA, & PROTEINS REVIEW
1. Making a copy of DNA is called _________________________.
2. Which nitrogen base isn’t used during this process?
3. Name the enzyme you learned about that adds the complementary
nucleotides and spell checks to make sure the new copy is correct.
4. This process of copying an RNA message from the DNA code is called
___________________
_.
5. Tell where in the cell this happens.
6. USE THE mRNA CODE
WHEEL to tell the amino acid
sequence coded for by the
following message:
U C A A A A U U C
7. Which kind of RNA has an ANTICODON region and carries the amino acids to the
ribosome?
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8. Name the parts/structures of a cell:
A = __________________
B = __________________
C = __________________
D = __________________
E = __________________
F = __________________
Label the codon & anticodon @ E.
9. Tell several ways DNA is different from RNA.
10. What do we call the small pieces of DNA that are edited out of the mRNA message
before it is expressed?
11. DNA that is SPREAD OUT in the nucleus of NON-DIVIDING cells is called ____.
12. When making DNA, CYTOSINE always pairs with
_______________________.
13. Using an RNA message to make a protein is called
________________.
14. Name this subunit used to build DNA and RNA.
15. Give the complementary DNA strand. A T T
G C C
A G C
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16. NAME THIS KIND OF RNA.
17. Name the molecule attached at the arrow.
18. An experiment conducted by Alfred Hershey and
Martha Chase showed that:
19. PROTEIN SYNTHESIS could also be called
________________.
20. Nitrogen bases made up of TWO
RINGS are called
________________ Name them.
21. Name this subunit used to build PROTEINS.
22.
Label W, X, Y & Z.
23. Which type(s) of RNA is/are involved in protein synthesis?
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24. ___ & ___ are given credit for discovering the
structure of DNA.
25. The three bases on the tRNA molecule that are
complementary to one of the mRNA codons are called
the
26. According to Chargaff’s rules, which nucleotide is
always paired with Adenine IN A DNA MOLECULE?
27. Ribosomes are made out of
28. DNA replication results in two DNA molecules that are said to be semiconservative. This
means 29. Where in the cell does transcription take place?
30. Where in the cell does translation take place?
31. How many codons are needed to specify THREE AMINO ACIDS?
32. What did the Hershey-Chase blender experiment help prove?
33. Nitrogen bases with only 1 ring are called ______________________. Name them.
34. Name the nucleic acid that is double stranded and contains deoxyribose sugar.
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How DNA Controls the Workings of the Cell
Below are two partial sequences of DNA bases (shown for only one strand of DNA). Sequence 1
is from a human and sequence 2 is from a cow. In both humans and cows, this sequence is part
of a set of instructions for controlling a bodily function. In this case, the sequence contains the
gene to make the protein insulin. Insulin is necessary for the uptake of sugar from the blood.
Without insulin, a person cannot use digest sugars the same way others can, and they have a
disease called diabetes.
Using the DNA sequence, make a complimentary
RNA strand from both the human and the cow.
Write the RNA directly below the DNA strand
(remember to substitute U’s for T’s in RNA)
Use one of the codon tables in this packet to
determine what amino acids are assembled
to make the insulin protein in both the cow
and the human. Write your amino acid chain
directly below the RNA sequence.
Sequence 1 – Human
DNA : C C A T A G C A C G T T A C A A C G T G A A G G T A A
RNA :
Amino Acids:
Sequence 2 – Cow
DNA :
C C G T A G C A T G T T A C A A C G C G A A G G C A C
RNA:
Amino Acids:
Analysis
1. The DNA sequence is different for the cow and the human, but the amino acid chain produced
by the sequence is almost the same. How can this happen?
2. Could two humans (or two cows) have some differences in the DNA sequence for insulin, yet
still make exactly the same insulin proteins? Explain.
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Nucleic Acids ~ DNA - The Double Helix
Recall that the nucleus is a small spherical, dense body in a cell. It is often called the
"control center" because it controls all the activities of the cell including cell reproduction,
and heredity. Chromosomes are microscopic, threadlike strands composed of the chemical
DNA (short for deoxyribonucleic acid). In simple terms, DNA controls the production of
proteins within the cell. These proteins in turn, form the structural units of cells and control
all chemical processes within the cell. Think of proteins as the building blocks for an
organism, proteins make up your skin, your hair, and parts of individual cells. The proteins
that are made largely determine how you look. The proteins that will be made for your body
are determined by the sequence of DNA in the nucleus.
What important polymer is located in the nucleus? _______________
___________ is the instructions for making a cell's ______________.
Chromosomes are composed of genes, which is a segment of DNA that codes for a
particular protein, which in turn codes for a trait. Hence you hear it commonly referred to
as the gene for baldness or the gene for blue eyes. Meanwhile, DNA is the chemical in which
genes and chromosomes are made. DNA is called a nucleic acid because it was first found in
the nucleus. We now know that DNA is also found in some organelles such as the
mitochondria and chloroplasts. It is the DNA in the nucleus that actually controls the cell's
workings.
_______ on chromosomes code for specific ___________ in a cell.
DNA is also found in _____________ and ____________.
In 1953, James Watson and Francis Crick established the structure of DNA. The
shape of DNA is a double helix, which is like a twisted ladder. The sides of the ladder are
made of alternating sugar and phosphate molecules. The sugar is a pentose called
deoxyribose. Color all the phosphates pink (one is labeled with a "p"). Color all the
deoxyribose sugars blue (one is labeled with a "D").
What is meant by a double helix? ____________________________
Who was Rosalind Franklin?
Name a pentose sugar. _________________
The sides of DNA are made of _____________ and ______________.
The rungs of the ladder are pairs of 4 types of nitrogen bases. The bases are known
by their coded letters --- A, G, T, and C. These bases always bond in a certain way.
Adenine will only bond to thymine. Guanine will only bond with cytosine. This is known as the
"Base-Pair Rule." The bases can occur in any order along a strand of DNA. The order of
these bases is the code that contains the instructions. For instance, ATGCACATA would
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code for a different gene than AATTACGGA. A strand of DNA contains millions of bases.
(For simplicity, the image only contains a few.)
What makes up the "rungs" of DNA? ____________________
What will pair with adenine? _____________
Color the thymines orange.
Color the adenines green.
Color the guanines purple.
Color the cytosines yellow.
***Note that that the bases attach to the sides of the ladder at the sugars and not
the phosphate.
The DNA helix is actually made of repeating units called nucleotides. Each nucleotide
consists of three molecules: a sugar (deoxyribose), a phosphate, which links the sugars
together, and then one of the four bases. Two of the bases are purines - adenine and
guanine. The pyrimidines are thymine and cytosine. Note that the pyrimidines are single
ringed and the purines are double ringed. Color the nucleotides using the same colors as you
colored them in the double helix.
Nucleotides are made of a pentose ___________, a ____________, and a nitrogencontaining __________.
Name 2 bases with double C-N rings. ____________________
The two sides of the DNA ladder are held together loosely by hydrogen bonds. The
DNA can actually "unzip" when it needs to replicate - or make a copy of itself. DNA needs to
copy itself when a cell divides, so that the new cells each contain a copy of the DNA.
Without these instructions, the new cells wouldn't have the correct information. The
hydrogen bonds are represented by small circles. Color the hydrogen bonds grey.
____________ bonds between bases must be broken to copy DNA.
Copying DNA to make two, identical DNA molecule is called ____________.
Messenger RNA
So, now, we know the nucleus controls the cell's activities through the chemical DNA,
but how? It is the sequence of bases that determine which protein is to be made. The
sequence is like a code that we can now interpret. The sequence determines which proteins
are made and the proteins determine which activities will be performed. This is how the
nucleus is the control center of the cell. The only problem is that the DNA is too big to go
through the nuclear pores so a chemical is used to read the DNA in the nucleus. That
chemical is messenger RNA (mRNA). The messenger RNA (mRNA) is small enough to go
through the nuclear pores. It takes the "message" of the DNA to the ribosomes and "tells
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them" what proteins are to be made. Recall that proteins are the body's building blocks.
Imagine that the code taken to the ribosomes is telling the ribosome what is needed - like a
recipe.
Messenger RNA is similar to DNA, except that it is a single strand, and it has NO thymine.
Instead of thymine, mRNA contains the base Uracil. In addition to that difference, mRNA
has the sugar ribose instead of deoxyribose. RNA stands for Ribonucleic Acid. Color the
mRNA as you did the DNA, except Color the ribose a DARKER BLUE, and
the
uracil brown.
mRNA has a ____________ strand of nucleotides.
__________ replaces __________ on RNA.
_________ is the pentose sugar on RNA.
__________, not DNA can leave the nucleus through ________ in the nuclear envelope.
Proteins are made at the _____________.
The Blueprint of Life
Every cell in your body has the same "blueprint" or the same DNA. Like the blueprints
of a house tell the builders how to construct a house, the cellular DNA "blueprint" tells the
cell how to build the organism. Yet, how can a heart be so different from a brain if all the
cells contain the same instructions? Although much work remains in genetics, it has become
apparent that a cell has the ability to turn off most genes and only work with the genes
necessary to do a job. We also know that a lot of DNA apparently is nonsense and codes
for nothing. These regions of DNA that do not code for proteins are called "introns," or
sometimes "junk DNA.” The sections of DNA that do actually code for proteins are called
"exons."
__________ are non-coding segments of DNA.
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DNA Molecule
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