Transcript Teaching the Concept of Protein Synthesis Rebecca

Teaching the Concept of
Protein Synthesis
Rebecca Lostracco
Jacqueline McCann
Introduction to Protein Synthesis
If you asked any body builder, they
would tell you that muscles are built
from protein. But have they ever
wondered how proteins are
actually made in our body?
It all starts with one thing: DNA!
Now you just create protein
from DNA. Sounds simple, right?
Wrong!
To understand this concept, you’ll
need to learn about the
central dogma of transcription
Really, really
and translation.
Important!!
Lesson Sequence

Lesson 1: Protein Synthesis: An Overview
 The Central Dogma, RNA, The Genetic Code

Lesson 2: Transcription
 Initiation, Elongation, Termination

Lesson 3: Translation
 The Ribosome, Transfer RNA, Elongation of the Polypeptide Chain,
Termination

Lesson 4: Control Mechanisms
 The lac Operon, the trp Operon

Lesson 5: Mutations
 Types of Mutation, Causes of Mutation

Lesson 6: Differences Between Eukaryotes and Prokaryotes
Curriculum Expectations
D2.4 investigate and analyse the cell components
involved in the process of protein synthesis,
using appropriate laboratory equipment and
techniques, or a computer simulation
D3.2 compare the structures and functions of
RNA and DNA, and explain their roles in the
process of protein synthesis
D3.3 explain the steps involved in the process of
protein synthesis and how genetic expression is
controlled in prokaryotes and eukaryotes by
regulatory proteins (e.g., the role of operons in
prokaryotic cells; the mechanism of gene expression
in eukaryotic cells)
The Central Dogma:
Teaching Approach

Video demonstration of Protein Synthesis
The Central Dogma:
Teaching Approach

Protein Synthesis Virtual Lab
 Students use an inquiry-based approach to transcribe a DNA
molecule into RNA, and then translate the mRNA into a protein
 Students interactively learn more about transcription and
translation
Transcription and Translation Virtual Lab
The Central Dogma:
Teaching Approach

Protein Synthesis Role-Play
 Teacher ropes off a designated area as the nucleus where transcription
must occur. The rest of the classroom is the cytoplasm where
translation will occur.
 8 students are assigned to DNA sequences (24 nucleotides in each)
 8 students are assigned to complementary mRNA sequences
 8 students are assigned to complementary tRNA anticodons with
corresponding amino acids (polypeptide chain)
 8 special learning opportunity messages (Ex. “Ribosomes move along
the mRNA in a 5’ to 3’ direction, while reading the coding sequence.”)
are posted around the classroom corresponding to amino acid
polypeptide chains
The Central Dogma:
Teaching Approach

Protein Synthesis Role Play Continued
 DNA students and mRNA students remain in nucleus during
transcription. After transcription, mRNA students move into cytoplasm,
where tRNA students are waiting for translation.
 DNA students begin by writing down the complimentary RNA
sequence to their DNA sequence (transcription). They then search the
nucleus for their matching mRNA student.
 mRNA student then leaves the nucleus and uses the genetic code to
write down the corresponding amino acids to their RNA sequence
(translation). They then search the cytoplasm for their matching tRNA
student.
 The tRNA student then searches for the
special message associated with their
polypeptide chain, thus completing
the task.
Potential Student Difficulties
• Abstract concept – may be hard for students to picture
• Remembering that in RNA, Thymine is replaced with Uracil
• Recognizing the matches between nucleotide bases and
amino acids (i.e., using the genetic code table)
• Distinguishing between DNA and RNA as well as between the roles
of mRNA and tRNA
 mRNA carries coded DNA message
 tRNA carries amino acids
• Recognizing a stop codon which
signals for translation to end
• Only 2 tRNA molecules can
attach to the ribosome at a time
• Polypeptide chain is transferred from
one tRNA to the other before tRNA
leaves the ribosome
Solutions to Student Difficulties
• Role-play activity will help to make concept more concrete
• Students can make their own mnemonics
for remembering stop codons
(UAU, UAG, UGA)
• Having an anchor chart with
nucleotide bases and their
corresponding amino acids
• During role-play activity, emphasize the distinction between mRNA
and tRNA by having the students in those groups wear a label
• Create a T-Chart/Venn Diagram to compare roles of DNA & RNA
and mRNA & tRNA
• Model translation in role-play activity slowly and clearly for the
students
• Have students proceed step-by-step, explaining their role in the
process
Safety Considerations
• This unit includes a virtual lab, which makes the main
safety concern appropriate internet conduct
• To safely implement the role-play
activity, the classroom will need to
be free from clutter with space for
students to move around
• Students will be given explicit
instructions on the role play activity so they
are aware of the expectations how to execute their role
Practical Applications
“What makes a Firefly Glow?”
• demonstration of how protein synthesis is involved
in making a firefly glow
Foods and Protein Synthesis
• examples of foods that increase
protein synthesis to support
muscle building
Exercise and Protein Synthesis
• discuss the rate of protein
synthesis in relation to exercise
Differentiated Assessment
• Students would have a choice for their culminating task assessment on protein
synthesis. The following tasks are targeted to students’ multiple intelligences:
 A poster displaying the process of protein synthesis (Visual)
 A song about the concept of protein synthesis (Musical)
 A 3-D model showing the main “players” in protein synthesis (Kinesthetic)
 A videotaped oral story about the process of protein synthesis (Linguistic)
 A journal entry on what they learned about protein synthesis (Intrapersonal)
 A lesson on protein synthesis that is taught to the class (Interpersonal)
 A lab activity involving transcription of provided DNA nucleotide sequences
into mRNA, splicing of the mRNA, and translation of the mRNA into a
protein (Logical)
• Students’ understanding of the concepts of protein synthesis would also be
evaluated on a unit test
• Formative assessment would be completed based on students’ contributions to
class discussions during role-play and participation in the online lab