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Module 1
Biotechnology Basics
Copyright © Texas Education Agency 2012. All rights reserved.
Lessons for Module 1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
Overview of Biotechnology
Cell Structure and Function
DNA Structure and Function
Protein Synthesis
Protein Structure and Function
Math Skills
Lab Overview
Copyright © Texas Education Agency 2012. All rights reserved.
Goals for Lesson 1.5
Describe the molecular structure of a protein.
Describe gene regulation strategies.
Name different types of mutations and give
examples of consequences of mutations.
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Protein Structure
 Once the amino acid chain is
released from the ribosome, a
number of modifications are
made in order for the protein
to perform its intended
function.
 The protein must fold into its
appropriate 3-dimensional
shape.
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Protein Structure
Proper folding of the protein is essential for
activity because it must bind its substrate to
perform its job.
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Protein Structure
 Primary structure is the peptide
bonds in a chain of amino acids.
 Secondary structure is hydrogen
bonding between amino acids forms
alpha-helices and beta-sheets.
 Tertiary structure is the three
dimensional folding of protein due to
disulfide linkages and hydrophobic
interactions between alpha-helices
and beta-sheets.
 Quaternary structure is the
aggregation of multiple polypeptide
chains.
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Control of Gene Expression
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Control of Gene Expression
Prokaryotes cluster genes into operons that are
transcribed together to give a single mRNA
molecule.
Bacterial Chromosome
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Control of Gene Expression
Lac Operon
 Promoter region allows RNA polymerase to attach
and begin transcription.
 Operator region is in the middle of the promoter.
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Control of Gene Expression
If a repressor protein is bound to the operator,
RNA polymerase cannot pass to transcribe the
genes.
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Control of Gene Expression
When the inducer
(lactose) binds to the
repressor protein, it
changes shape and falls
off the operator region.
Now RNA polymerase
can pass and transcribe
the genes into mRNA.
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Animation: Lac Operon
Central Dogma
DNA codes for RNA which codes for proteins.
Proteins confer phenotypic traits.
An alteration in the DNA code will ultimately
effect protein function.
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Mutations
Mutations are changes in the DNA
sequence.
Mutations can be inherited or acquired.
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Mutations
Mutagens are agents that interact with
DNA to cause mutations.
Examples are chemicals and radiation.
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Mutations
 Point mutation changes a single base.
 Point mutations can be silent, meaning they code for the
same amino acid.
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Mutations
Point mutations can also code for a structurally
similar amino acid.
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Mutations
 Point mutations are not always harmless.
 If the mutation occurs on a critical amino acid in the active site of
the protein, it can be detrimental, as in the case of sickle cell
anemia.
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Mutations
Frameshift mutations cause a shift in the
reading frame by adding or deleting nucleotides.
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Mutations
An example of a deletion causing a premature
stop codon
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Resources
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