Unit 7: Transcription & Translation - Ivory

5 Classes

Dates

Day

IB Topic

Activities

Objectives

Homework

12/14 & 12/17

33

Quiz: Transcription, 2.7/7.2

DNA Test Results

Introduction to Protein Synthesis

Transcription Animations

Complete Paper Airplanes

Protein Synthesis Activity

  • The amino acid sequence of polypeptides is determined by mRNA according to the genetic code
  • Codons of three bases on mRNA correspond to one amino acid in a polypeptide
  • Transcription is the synthesis of mRNA copied form the DNA base sequences by RNA polymerase
  • Skill: Use a table or mRNA codons and their corresponding amino acids to deduce the sequence of amino acids coded by a short mRNA strand of known base sequence.
  • Skill: Deducing the DNA base sequence for the mRNA strand.
  • Transcription occurs in a 5’ to 3’ direction.

2.7/7.3 Translation Notes Part 1

Reading: 337-341

12/18 & 12/19

34

Quiz: Translation, 2.7/7.3 Part 1

Translation Walkthrough & Explanation

Protein Synthesis Activity

Videos & Animations

  • Initiation of translation involves assembly of the components that carry out the process.
  • Synthesis of the polypeptide involves a repeated cycle of events.
  • Disassembly of the components follows termination of translation.
  • Free ribosomes synthesize proteins for use primarily within the cell.
  • Bound ribosomes synthesize proteins primarily for secretion or for use in lysosomes.
  • Translation can occur immediately after transcription in prokaryotes due to the absence of a nuclear membrane.
  • The sequence and number of amino acids in the polypeptide is the primary structure.
  • The secondary structure is the formation of alpha helices and beta pleated sheets stabilized by hydrogen bonding.
  • The tertiary structure is the further folding of the polypeptide stabilized by interactions between R groups.
  • The quaternary structure exists in proteins with more one polypeptide chain.
  • Translation is the synthesis of polypeptides on ribosomes
  • Translation depends on  complementary base pairing between codons on mRNA and anticodons of tRNA
  • Application: tRNA- activating enzymes illustrate enzyme-substrate specificity and the role of phosphorylation.
  • Skill: Identification of polysomes in electron micrographs of prokaryotes and eukaryotes.

2.7/7.3 Translation Notes Part 2

Reading: 337-341

12/20 & 12/21

35

Quiz: Translation, 2.7/7.3 Part 2

Exploration Practice 1

1/7 & 1/8

36

Influencing Gene Expression: Epigenetics & Regulation

Gene Regulation

  • Skill: The use of molecular visualization software to analyse the structure of eukaryotic ribosomes and a tRNA molecule.

  • Nucleosomes help to regulate transcription in eukaryotes.
  • Eukaryotic cells modify mRNA after transcription.
  • Splicing of mRNA increases the number of different proteins an organism can produce.
  • Gene expression is regulated by proteins that bind to specific base specific base sequences in DNA.
  • The environment of a cell and of an organism has an impact on gene expression.
  • Application: The promoter as an example of non-coding DNA with a function.
  • Skill: Analysis of changes in the DNA methylation patterns.

Exploration Practice 1

1/9 & 1/10

37

Review

Protein Synthesis Review Activity

Videos & Animations

Exploration Practice 1 peer review via peer grade

Practice Test

Exploration Practice 2

Exploration Practice 3

Review of Standards

PCR Virtual Lab

1/11 DNA Test Retakes Deadline

1/11 & 1/14

38

Transcription & Translation Assessment

Discuss the potential benefits and possible harmful effects of one example of genetic modification

Exploration #2