Download Name: ____________ Pd.: ______ Date: Cells cannot make

Name: _____________________________________________________ Pd.: ________ Date: ______________________
Homework – DNA Transcription
1. Cells cannot make proteins directly from DNA. They must convert the DNA into an intermediate molecule called
RNA, or ribonucleic acid. That conversion process is called __________________________________________.
2. The __________________ _________________ of molecular biology
states that information flows in one direction, from DNA to RNA, to
proteins.
3. It involves three major processes in a eukaryotic cell:
__________________________ (copies DNA)
__________________________ (converts DNA to RNA)
__________________________ (interprets an RNA message to a string
of amino acids which make up proteins)
4. The double helix structure explains how DNA can be replicated, or copied, but it does not explain how a gene
works. Genes are coded DNA instructions that control the production of proteins within the cell. The first step in
decoding these genetic messages is to copy part of the nucleotide sequence from DNA into RNA, or ribonucleic
acid. These RNA molecules then carry out the process of making proteins. You can think of an RNA molecule as
a disposable copy of a segment of DNA. However, there are three main differences between RNA and DNA.
Complete the table below to summarize the three main differences:
DNA
RNA
Sugar is deoxyribose
Molecule is double-stranded
Bases are A, T, C, G
5. Transcription is the process of copying a sequence of DNA to produce a complementary strand of RNA. During
the process of transcription, a ____________, not an entire chromosome, is transferred into an RNA message.
6. RNA molecules have many functions, but in the majority of cells most RNA molecules are involved in just one jobprotein synthesis. The assembly of amino acids into proteins is controlled by RNA. There are three main types of
RNA. Complete the table below to summarize the function of each type of RNA:
Type of RNA
Messenger (mRNA)
Ribosomal (rRNA)
Transfer (tRNA)
Function of RNA
7. Transcription requires
an enzyme to bind to
the DNA and separate
the DNA strands. The
enzyme is called RNA
_________________.
8. During transcription
of a DNA gene to a
messenger RNA
strand, the adenine
nucleotide is
transcribed to a
_________________
nucleotide.
9. Where in the cell do both transcription and replication occur in eukaryotic cells? __________________________
10. The diagram below represents a portion of a DNA molecule that is being transcribed to mRNA. What are the
nucleotide bases 1 through 10 that will be transcribed from the nucleotides of the DNA strand? Write the letters
of the RNA nucleotides in the spaces.
11. What is produced during transcription?
12. Unlike DNA, RNA contains
a. RNA molecules
a. adenine
b. DNA molecules
b. uracil
c.
c. Phosphate groups
RNA polymerase
d. proteins
d. thymine