Download DNA and Protein Synthesis Worksheet

Name:…………………………………………………….
Date: ……………………
DNA and Protein Synthesis Worksheet
This worksheet accompanies DNA Summary
and Genes and Protein Synthesis Summary.
1. Answer the following questions about DNA.
a) Label the image using the words in the box below.
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DNA double helix
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chromosome
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base pairs
gene
Name:…………………………………………………….
Date: ……………………
b) Fill in the missing words in the text using the words in the box below.
double helix
gene
bases
genetic code
base pairs
DNA
cell activity
Chromosomes are found in the nucleus of cells and are made up of long molecules of
tightly coiled …………………. These molecules carry coded information that controls
………………… and the characteristics of the organism. A ………………… is a small
section of a DNA molecule. DNA has a ………………… structure that is formed by two
strands that are coiled together. These strands of the DNA molecule are linked by
………………… which are held together by weak hydrogen bonds. The four bases of DNA
are adenine (A), thymine (T), cytosine (C) and guanine (G). These …………………
always pair up in the same way – A with T, and C with G. The sequence of these bases
along a DNA molecule is what forms the ………………….
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Name:…………………………………………………….
Date: ……………………
2. DNA controls the function of cells by controlling the production of proteins. Answer
the following questions about proteins.
a) Explain how the structure of a protein is determined by the order of base pairs in a DNA
molecule. Include the following terms: amino acids, triplet, sequence, base code.
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b) Different proteins are made of different sequences of amino acids joined together to form
polypeptide chains. Each protein consists of one or more polypeptide chains. The number
and sequence of amino acids in a protein determine its shape and biological functions.
Name two functions of proteins.
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c) Name two specific proteins.
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Name:…………………………………………………….
Date: ……………………
3. Fill in the gaps in the table below to complete the process of protein synthesis.
Stages in the process
What happens
A section of ………………… containing the gene unwinds
Stage 1
Stage 2 –
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and the two strands separate.
A molecule of RNA is produced, containing a copy of the
genetic information.
The new RNA molecule called ………………… RNA
Stage 3 – mRNA moves
out of the nucleus
(mRNA) leaves the nucleus and enters the cytoplasm.
The mRNA attaches to a ribosome in the cytoplasm.
Stage 4
The ribosome ……………...... the sequence of codons in
the mRNA.
As the mRNA passes through the ribosome, the correct
Stage 5 –
amino acid is added to the growing chain by tRNA. Amino
………………………………
acids link up to form a polypeptide.
A completed polypeptide chain is released into the
Stage 6 – Modification of
the protein.
cytoplasm. Several ………………… combine to form a
protein.
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Name:…………………………………………………….
Date: ……………………
4. Draw a diagram to show the process of transcription. Label your diagram using the
following terms: molecule of RNA, exposed bases, DNA strands, nucleus.
5. Gene mutations are caused by errors that occur during DNA replication. Gene
mutations can prevent the production of the protein that the gene normally codes for.
a) Describe what a gene mutation is.
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b) When do gene mutations occur?
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c) Give an example of a mutagenic agent that could interfere with DNA replication and cause
a gene mutation.
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