Download Study Guide B

From DNA to Proteins
Study Guide B
Answer Key
SECTION 2. STRUCTURE OF DNA
1.
2.
3.
4.
5.
6.
7.
8.
Nucleotide: Refer to the Visual Vocab in Section 2 for visual answers. Students should label:
phosphate group; nitrogen-containing base; and deoxyribose sugar.
4
the phosphate group and the deoxyribose sugar; the nitrogen-containing base
that it was of uniform width
by building models
The sugar-phosphate backbone is on the outside. Inside the structure, a base with two rings always
pairs with a base with only one ring.
A; G
DNA Double Helix: drawing should include sugar-phosphate backbone; nitrogen-containing
bases; and hydrogen bonds
The sugar-phosphate backbone is like the twisting handrails of the staircase, and the nitrogencontaining bases are like the steps that connect the railings to each other.
Because A only pairs with T and C only pairs with G, the amount of A will be equal to the amount
of T, and the amount of C will be equal to the amount of G.
SECTION 3. DNA REPLICATION
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
the process by which DNA is copied during the cell cycle
nucleus
S stage
so that every cell will have a complete set of DNA following cell division
something that serves as a pattern
ATCCATG
Proteins help unzip the DNA strand, hold the strands apart, and bond nucleotides together.
hydrogen bonds connecting base pairs
because each molecule consists of one old strand and one new strand
Enzymes unzip the helix.
DNA polymerase binds nucleotides together to form new strands that are complementary to the
original strands.
12. Two identical DNA molecules result.
13. origins of replication
14. proofreading
15. DNA polymerase is an enzyme that makes DNA by forming bonds between nucleotides. The “ase” ending signals that it is an enzyme. The first part of the word tells that the enzyme makes
DNA by stringing together lots of monomers to form polymers.
16. Replication is the process by which DNA is copied during the cell cycle. Accept any reasonable
answer. Students may compare replication to making copies on a copier.
17. Share the best bumper stickers with the class.
Study Guide B continued
SECTION 4. TRANSCRIPTION
1. replication (nucleus)
2. transcription (nucleus)
3. translation (cytoplasm)
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
1
From DNA to Proteins
Section 2: Structure of DNA
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Contains the sugar ribose
Has the bases A, C, G, and T
Typically single-stranded
RNA polymerase
A large transcription complex, including RNA polymerase and other proteins, assembles at the
start of a gene and begins to unwind the DNA. Using one strand of the DNA as a template, RNA
polymerase strings together a complementary strand of RNA. The RNA strand detaches from the
DNA as it is transcribed, and the DNA zips back together.
mRNA: intermediate message that is translated to form a protein; rRNA: forms part of
ribosomes; tRNA: brings amino acids from the cytoplasm to a ribosome to help make the growing
protein
Both occur within the nucleus of eukaryotic cells, are catalyzed by large enzymes, involve
unwinding of the DNA double helix, involve complementary base pairing of the DNA strand, and
are highly regulated by
the cell.
Replication occurs only once during each round of the cell cycle and makes a double-stranded
copy of all the DNA in a cell. Transcription occurs repeatedly throughout the cell cycle to make
proteins, rRNAs, and tRNAs as needed by a cell. Transcription makes a single-stranded
complement of only a particular DNA sequence.
mRNA is a form of the DNA message that tells the cell what type of protein to make. rRNA is a
key component of ribosomes. tRNA transfers, or carries, amino acids from the cytoplasm to the
ribosome.
the process of copying a sequence of DNA to produce a complementary strand of RNA
Section 5. Translation
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
the process that converts an mRNA message into a polypeptide, or protein
sequences of three nucleotides that code for an amino acid
RNA
the order in which nucleotides are read; they are read as a series of three, nonoverlapping
nucleotides
arginine (Arg)
stop codon
UGG
glycine (Gly)
Ribosomes, tRNA molecules
small
large
amino acid, anticodon
Cycle Diagram:
A. An exposed codon attracts a complementary tRNA bearing an amino acid.
B. the ribosome forms a peptide bond between the amino acids. It breaks the bond between the
first amino acid and tRNA.
C. the ribosome pulls the mRNA strand the length of one codon. The first tRNA exits the
ribosome, and another codon is exposed.
codons
anticodon
Stop codons indicate where translation is to stop. (Students may mention that methionine is also a
start codon.)
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
2
From DNA to Proteins
Section 2: Structure of DNA
Section 2: Structure of DNA
Study Guide B
KEY CONCEPT
DNA structure is the same in all organisms.
VOCABULARY
nucleotide
base pairing rules
double helix
MAIN IDEA: DNA is composed of four types of nucleotides.
In the space below, draw a nucleotide and label its three parts using words and
arrows.
1. How many types of nucleotides are present in DNA?
_______________________________________________________________
2. Which parts are the same in all nucleotides? Which part is different?
_______________________________________________________________
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
3
From DNA to Proteins
Section 2: Structure of DNA
Study Guide B continued
MAIN IDEA: Watson and Crick developed an accurate model of DNA’s threedimensional structure.
3. What did Franklin’s data reveal about the structure of DNA?
_______________________________________________________________
4. How did Watson and Crick determine the three-dimensional shape of DNA?
_______________________________________________________________
5. How does DNA base pairing result in a molecule that has a uniform width?
_______________________________________________________________
MAIN IDEA: Nucleotides always pair in the same way.
6. What nucleotide pairs with T? with C?
_______________________________________________________________
In the space below, draw a DNA double helix. Label the sugar-phosphate
backbone, the nitrogen-containing bases, and the hydrogen bonds.
Vocabulary Check
7. Explain how the DNA double helix is similar to a spiral staircase.
_______________________________________________________________
_______________________________________________________________
8. How do the base pairing rules relate to Chargaff ’s rules?
_______________________________________________________________
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
4
From DNA to Proteins
Section 2: Structure of DNA
Section 3: DNA Replication
Study Guide B
KEY CONCEPT
DNA replication copies the genetic information of a cell.
VOCABULARY
replication
DNA polymerase
MAIN IDEA: Replication copies the genetic information.
1. What is DNA replication?
_______________________________________________________________
2. Where does DNA replication take place in a eukaryotic cell?
_______________________________________________________________
3. When is DNA replicated during the cell cycle?
_______________________________________________________________
4. Why does DNA replication need to occur?
_______________________________________________________________
5. What is a template?
_______________________________________________________________
6. If one strand of DNA had the sequence TAGGTAC, what would be the
sequence of the complementary DNA strand?
_______________________________________________________________
MAIN IDEA: Proteins carry out the process of replication.
7. What roles do proteins play in DNA replication?
_______________________________________________________________
8. What must be broken for the DNA strand to separate?
_______________________________________________________________
9. Why is DNA replication called semiconservative?
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
5
From DNA to Proteins
Section 3: DNA Replication
Study Guide B continued
Use words and diagrams to summarize the steps of replication, in order, in the
boxes below.
10.
_______________
_______________
11.
12.
_______________
_______________
_______________
_______________
MAIN IDEA: REPLICATION IS FAST AND ACCURATE.
13. Human chromosomes have hundreds of _________________, where the DNA
is unzipped so replication can begin.
14. DNA polymerase has a __________________ function that enables it to detect
errors and correct them.
Vocabulary Check
15. Explain what DNA polymerase is by breaking the word into its parts.
_______________________________________________________________
16. Write a short analogy to explain what replication is.
_______________________________________________________________
Be Creative
17. People sometimes like to display bumper stickers that relate to their trade or
field of study. For example, a chemist may have a bumper sticker that says “It
takes alkynes to make the world.” Then, chemists or other people who know
that an alkyne is a molecule that contains carbon atoms joined by a triple bond
get a nice little chuckle out of the play on words. Use your knowledge of DNA
replication to write a bumper sticker.
_______________________________________________________________
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
6
From DNA to Proteins
Section 3: DNA Replication
Section 4: Transcription
Study Guide B
KEY CONCEPT
Transcription converts a gene into a single-stranded RNA molecule.
VOCABULARY
central dogma
messenger RNA (mRNA)
RNA
ribosomal RNA (rRNA)
transcription
transfer RNA (tRNA)
RNA polymerase
MAIN IDEA: RNA carries DNA’s instructions.
Label each of the processes represented by the arrows in the diagram below.
Write where each of these processes takes place in a eukaryotic cell in
parentheses.
1. _______________
DNA
RNA
2. _______________
_______________
Proteins
3. _______________
_______________
____________
Fill in the table below to contrast DNA and RNA.
DNA
RNA
4. Contains the sugar deoxyribose
5.
Has the bases A, C, G, and U
6. Typically double-stranded
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
7
From DNA to Proteins
Section 4: Transcription
Study Guide B continued
MAIN IDEA: Transcription makes three types of RNA.
7. What enzyme helps a cell to make a strand of RNA?
_______________________________________________________________
8. Summarize the three key steps of transcription.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
9. Write the basic function of each type of RNA in the chart below.
Type of RNA
Function
mRNA
rRNA
tRNA
MAIN IDEA: The transcription process is similar to replication.
10. List two ways that the processes of transcription and replication are similar.
_______________________________________________________________
11. List two ways that the end results of transcription and replication differ.
_______________________________________________________________
Vocabulary Check
12. How does the name of each type of RNA tell what it does?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
13. What is transcription?
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
8
From DNA to Proteins
Section 4: Transcription
Section 5: Translation
Study Guide B
KEY CONCEPT
Translation converts an mRNA message into a polypeptide, or protein.
VOCABULARY
translation
stop codon
codon
start codon
anticodon
MAIN IDEA: Amino acids are coded by mRNA base sequences.
1. What is translation?
_______________________________________________________________
2. What is a codon?
_______________________________________________________________
3. Would the codons in Figure 5.1 be found in a strand of DNA or RNA?
_______________________________________________________________
4. What is a reading frame?
_______________________________________________________________
Refer to Figure 5.1 to complete the table below.
Codon
Amino Acid or Function
5. AGA
6. UAG
7.
tryptophan (Trp)
8. GGA
MAIN IDEA: Amino acids are linked to become a protein.
9. _______________ and _______________ are the tools that help a cell
translate an mRNA message into a polypeptide.
10. The _______________ subunit of a ribosome holds onto the mRNA strand.
11. The _______________ subunit of a ribosome has binding sites for tRNA.
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
9
From DNA to Proteins
Section 5: Translation
Study Guide B continued
12. A tRNA molecule is attached to an _______________ at one end and has an
_______________ at the other end.
Fill in the cycle diagram below to outline the steps of translation.
Ribosome assembles on
start codon of mRNA
strand.
A.
B.
C.
When the ribosome
encounters a stop
codon, it falls apart and
the protein is released.
Vocabulary Check
13. What are AGG, GCA, and GUU examples of?
_______________________________________________________________
14. What is a set of three nucleotides on a tRNA molecule that is complementary
to an mRNA codon?
_______________________________________________________________
15. What do codons code for in addition to amino acids?
_______________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
10
From DNA to Proteins
Section 5: Translation
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
11
From DNA to Proteins
Section 7: Mutations