Chapter 12 Study Guide
Name: _______________________________________________________ Date: _________________ Period: _____________
1.
What are the two types of Nucleic Acids? How are they similar? How are they different?
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2.
DNA and RNA – they are nucleic acids, polymers, macromolecules and are made up of the
monomer nucleotides.
DNA is a double strand in the shape of a helix. Made up of the sugar deoxyribose and has the
nitrogen base Thymine. RNA is a single strand. Made up of the sugar ribose and has the
nitrogen base Uracil. RNA has three types.
What is the Central Dogma?
DNA ------- RNA --------Protein
Nucleolus -----Ribosomes -----Protein
3.
What did each of the scientists do?
a. Griffith - Experimented with mice and bacteria that cause pneumonia and demonstrated
TRANSFORMATION. Concluded that some FACTOR was responsible for the change.
b. Avery - Followed up on Griffith’s experiment, He then extracted the 4 macromolecules
from these dead cells, all of which were considered to be possible candidates for the
carriers of genetic information. He concluded that DNA is the source of genetic information.
c. Hershey and Chase - supported the conclusion - DNA is the source of genetic information
d. Chargaff – complimentary base pairing for DNA --- A-T and C-G
e. Watson and Crick/Rosalind Franklin – discovering structures and shape of DNA.
4.
What does DNA stand for? Write out the name – Deoxyribose Nucleic Acid
5.
What is the monomer of DNA? Nucleotide – made of deoxyribose sugar, a phosphate group and
a nitrogen base.
6.
Describe the structure of DNA. Include the following terms. Nitrogen bases, hydrogen bonds,
Deoxyribose, double helix, phosphate, backbone, rungs, and nucleotide. Include a diagram as
well.
DNA is made up of the four nitrogen bases known as Adenine, Thymine, Guanine and Cytosine.
The nitrogen bases are joined together by hydrogen bonds. The sugar that makes up DNA is
deoxyribose. DNA is a double stranded helix model. The sides (also known as the backbone)
are made of sugars and phosphates that alternate. The rungs are made of the nitrogen bases
pairs.
7.
What are the base pairing rules? Adenine with Thymine and Guanine with Cytosine for a DNA
molecule.
8.
What is the process of DNA replication? When does it take place?
Replication is a process of making a duplicate strand of DNA. It takes place in the nucleus and
happens during the S-phase of cell division.
9.
What are the steps of DNA replication?
Helicase (an enzyme) unwinds the DNA helix. DNA polymerase (another enzyme) attaches to each
strand of the DNA and starts moving along it adding complementary base pairs until the DNA
molecule has been fully replicated. Both molecules rewind and the result is two identical DNA
molecules.
10.
What is the role of the enzyme in DNA replication? What is the name of the enzyme?
Helicase (an enzyme) unwinds the DNA helix. DNA polymerase (another enzyme) adds
complementary base pairs.
11.
What is the relationship between the two molecules of DNA at the end of replication? What is
the relationship between the strands of DNA? Identical DNA molecules. One strand on the
molecule is an old/original and the other is a new complementary strand.
12.
DNA Strand 1: CTTAGGAAT
DNA Strand 2: GAATCCTTA
13.
What are the two processes of protein synthesis and where in the cell do they occur?
Transcription occurs in the nucleus because that is where DNA is located.
Translation occurs in the cytoplasm because that is where the ribosomes are found.
14.
What does Transcription make?
Makes a RNA molecule from the DNA code.
15.
What is the role of enzymes in transcription? What is the name of the enzyme?
RNA polymerase – its role is to add complementary RNA bases pairs by using the DNA as a code.
16.
What are the three kinds of RNA? What are their functions?
mRNA – made during transcription. It is carrying the message or code from DNA.
rRNA – the ribosome structure that contains the mRNA.
tRNA – translate the mRNA into specific amino acids which will code for specific enzymes.
17.
Describe the process of transcription.
Transcription takes place in the nucleus because DNA is too big to fit through the nuclear
pores. mRNA is made from the code of DNA.
1. DNA unwinds.
2. RNA Polymerase binds to DNA promoter site (beginning gene)
3. It adds complementary RNA nucleotides (U↔A) C-G
4. DNA termination sequence signals gene end.
5. RNA Polymersase releases DNA & RNA molecules.
18.
Describe the process of translation.
Translation takes place in the cytoplasm. RNA makes protein.
1. mRNA leaves nucleus
2. Ribosome attaches to mRNA start codon - AUG
3. mRNA codon pairs with tRNA anticodon delivering amino acid
4. Peptide bond forms between amino acids
5. mRNA stop codon signals end of translation (UAA, UAG, UGA). The ribosome releases the
newly formed polypeptide.
6. mRNA released & polypeptide complete
19.
What are the following?
a. Start codon – an amino acid that tells when to start translation of the RNA molecule, AUG
b. Stop codon - three different amino acids that tell when to stop translation of the RNA
molecule, UAA, UAG, UGA
c. Anticodon - complements to mRNA
d. Codons – three nucleotides that code for specific amino acids.
e. Polypeptide – a chain of amino acids.
f. Peptide bonds – join the amino acids together, form polypeptide into protein.
g. Amino acids – monomer of protein, used to build specific proteins for the body.
20.
Mutations that are passed on to offspring are sex cell mutations.
21.
What do you call mutations that affect only the individual? Somatic mutations because they
affect the body cells.
22.
Describe substitution, deletions and insertion point muttaions.
Substitution  1 nitrogen base gets substituted by another nitrogen base; this results in a
new codon
Sickle Cell Anemia: substitute A for T
Nucleotide deletions & insertions
– Frame-shift mutations
– Changes amino acid sequence
23.
Which type of point mutation (substitution or deletion/insertions) has the biggest effect?
24.
Why are deletions and insertion point mutations called frame-shift mutations?
They shift the entire frame which will change all the amino acids in the sequence.
25.
What holds the nitrogen bases together? Hydrogen bonds.
26.
Why is transcription necessary for protein synthesis?
DNA is too big to fit through the nuclear pores. The only way DNA can send its message to the
body is to make RNA first because RNA is small enough to fit through the pores while in a
ribosome. The RNA will then be able to make the specific protein for the body by using mRNA,
rRNA and tRNA.
27.
Which nucleotides are purines? Which are the pyrimidines?
A and G are purines
T and C are pyrimidines
28.
What are the three components of a RNA nucleotide?
Ribose sugar, a phosphate group and a nitrogen bases (A, U, C G) NO THYMINE.
29.
What is the difference between a codon and an anticodon?
A codon codes for a specific amino acid using DNA as the source. Anticodons complement the
mRNA strand to help build specific proteins.
30.
Give the RNA sequence for the following DNA sequence
a. TAC TTA CGT GGA CCT ATC
AUG AAU GCA CCU GGA UAG
Know how to use this Genetic Code wheel during Protein
Synthesis
GUC = _____Valine_________________________
AAG = _____Lysine_________________________
UGA = _____Stop_________________________
UUA = _____Leucine________________________
CCC = _____Proline_________________________
Identify the specific type of RNA shown below
What is letter X? nucleotide
rRNA
tRNA
mRNA
A. Nucleus with nuclear pores.
B. mRNA strand coming out of nucleus
C. Ribosome
D. tRNA
E. Anticodon
F. amino acid sequences
G. mRNA
A. original DNA strand
B. new DNA strand
C. phosphate/sugar backbone
D. mRNA strand
E. start codon
F. codon
X. transcription
Y. translation
A. amino acid
B. tRNA
C. anticodon
Process: DNA replication
D. codon
E. mRNA
F. ribosome
G. polypeptide chain