Download HW-Replication and Transcription

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HW-Replication and Transcription
Name:
Class:
Date:
1. Describe the structure of DNA.
2. State the base-pairing rules of DNA.
3. What is replication?
4. What is RNA? How is it different from DNA?
5. What is transcription? (Include the name and function of the enzyme involved.)
6. How is mRNA involved in protein synthesis?
7. Write the mRNA transcription of the DNA sequence presented below. Next, write the tRNA anticodons that
would pair with the mRNA transcription. Finally, write the amino acids coded for by the mRNA transcription
using the genetic code (p. 292 of your text).
DNA (Mark off the triplets.) T A C C T G T T C A T A A T T
mRNA codons
tRNA anticodons
Amino acid sequence
8. If you transcribed the “wrong” side of the DNA molecule, what would the result be? How might this affect the
proteins that the organism produced?
9. What is an advantage of having DNA remain in the nucleus of eukaryotic cells?
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HW-Replication and Transcription
Name: KEY
Class:
Date:
1. Describe the structure of DNA.
DNA is made of two chains of nucleotides twisted around a central axis. Each nucleotide is made up of the
sugar deoxyribose, a phosphate group, and a base.
2. State the base-pairing rules of DNA.
Adenine binds with thymine. Guanine binds with cytosine.
3. What is replication?
Replication is the process of making another copy of DNA.
4. What is RNA? How is it different from DNA?
RNA is a single-stranded nucleic acid that contains the information from DNA. It is also made of nucleotides, but
has the sugar ribose instead of deoxyribose and the base uracil instead of thymine.
5. What is transcription? (Include the name and function of the enzyme involved.)
Transcription is the process of making mRNA from a DNA template. The enzyme that adds RNA nucleotides to
the DNA template is called RNA polymerase.
6. How is mRNA involved in protein synthesis?
mRNA is made from a DNA template. The final mRNA strand (exons only) carries genetic information from the
DNA in the nucleus to the site of protein synthesis in the cytoplasm of a eukaryotic cell.
7. Write the mRNA transcription of the DNA sequence presented below. Next, write the tRNA anticodons that
would pair with the mRNA transcription. Finally, write the amino acids coded for by the mRNA transcription
using the genetic code (p. 292 of your text).
DNA (Mark off the triplets.) T A C/ C T G/ T T C/ A T A/ A T T
mRNA codons
A U G/ G A C/ A A G/ U A U/ U A A
tRNA anticodons
U A C/ C U G/ U U C/ A U A/ A U U
Amino acid sequence
methionine-aspartate-lysine-tyrosine
8. If you transcribed the “wrong” side of the DNA molecule, what would the result be? How might this affect the
proteins that the organism produced?
It would result in different amino acids for most (if not all) of the polypeptide chain. This would result in a
completely different (probably nonfunctional) protein.
9. What is an advantage of having DNA remain in the nucleus of eukaryotic cells?
The main advantage is that the nucleus is an isolated and protected area for storing genetic information.
(Another effect: Eukaryotes can house more DNA and undergo more complex cell divisions than prokaryotes
can.)