Overview for teachers: chemistry unit planner QLD curriculum

 

Unit Overview

The polymerase chain reaction (PCR) is a laboratory technique used for copying large quantities of specific DNA sequences. Millions of copies of DNA can be created in just a few hours with PCR. The amplified DNA is used for diagnostic purposes and also for genetic manipulation. PCR can be used to detect pathogens in food, ingredients, crops, etc.

Students will spend time building their knowledge and conceptual understanding about the mechanisms and techniques of PCR.

A supervised assessment will be given at the end of the unit to test the students' understanding of the subject matter.

Suggested Texts:

Smith, D., Gould, M., Monteath, S., Smith, R. 2006. Chemistry In Use: Book 2, McGraw-Hill Australia Pty Ltd, North Ryde

MCKay, D., Walker, M. 2006. Unravelling Genes. A layperson's guide to genetic engineering. Pearson Education Australia. Sydney

Deep Understandings

Through developing comprehensive knowledge and conceptual understanding of the mechanisms and techniques of PCR students will be able to explain the advantages and applications of DNA amplification, analysis and manipulation in primary industry.

Students will learn and use DNA procedures and techniques such as DNA extraction, DNA electrophoresis and PCR.

Links will be formed between the subject matter and practical skills so that reflective evaluations on scientific investigations can occur.

Targeted Key Concepts and Key Ideas

Key Concepts Key Ideas

Structure:

  1. All matter is composed of atoms
  2. Materials can be categorised and represented symbolically and their macroscopic properties can be explained and predicted from understandings about electronic structure and bonding

Reactions:

  1. Specific criteria can be used to classify chemical reactions
  2. Chemical reactions involve energy changes
  3. The mole concept and stoichiometry enable the determination of quantities in chemical processes
  4. Specialised qualitative and quantitative techniques are used to determine the quantity, composition and type of reaction
  5. Chemical reactions are influenced by the conditions under which they take place and, being reversible, may reach a state of equilibrium

S1.1 - Matter is composed of atoms which, in turn, contain protons and neutrons in a nucleus, and electrons outside the nucleus.

S1.2 - The number of positively charged protons is equal to the number of negatively charged electrons in a neutral atom, and determines all the chemical properties of an atom.

S1.3 - An element is a substance in which all atoms have the same number of protons.

S1.5 - Every element is assigned a unique chemical symbol.

S1.6 - The atomic mass of an atom is arbitrarily defined relative to the mass of the isotope carbon-12.

S1.7 - In modern theories of atomic structure, electrons are viewed as occupying orbitals which are grouped in electron shells.

S2.2 - The macroscopic properties are related to their microscopic properties.

S2.3 - Pairs of atoms may be bound together by the sharing of electrons between them in a covalent bond.

S2.4 - Two or more atoms bound together by one or more covalent bonds form a molecule, with definite size, shape and arrangement of bonds.

S2.7 - When chemical bonds, whether ionic or covalent, are formed between different elements, a chemical compound is obtained, which can be represented by a chemical formula.

S2.8 - Forces weaker than covalent bonding exist between molecules.

S2.10 - Materials may be elements, compounds or mixtures.

S2.11 - In compounds containing carbon-hydrogen bonds (known as organic compounds), the carbon atoms bind to one another through single, double or triple covalent bonds to form chains or rings.

R1.1 - Redox reactions involve a transfer of electrons and a change in oxidation number.

R1.2 - Precipitation reactions result in the appearance of a solid from reactants in aqueous solution.

R1.3 - Acid-base reactions involve transfer of protons from donors to acceptors.

R1.4 - Polymerisation reactions produce large molecules with repeating units.

R2.1 - All chemical reactions involve energy transformations.

R3.2 - Every chemical reaction can be represented by a balanced equation, whose coefficients indicate both the number of reacting particles and the reacting quantities in moles.

R3.4 - The use of molarity for expressing concentration allows easy interconversions between volume of solution and moles of solute.

R4.1 - Techniques such as volumetric and gravimetric analysis are used to determine amounts of reactants and products.

R4.2 - Specialised techniques and instrumentation are used in chemical analysis.

R4.3 - Qualitative and quantitative testing may be used to determine the composition or type of material.

R5.1 - Chemical reactions occur at different rates and changing the nature of the reactants, temperature, or concentration, or introducing a catalyst, may alter these.

R5.2 - Life is maintained by chemical reactions, especially those catalysed by large molecules called enzymes.

R5.3 - Chemical reactions may be reversible.

Unit Focus

Knowledge and Conceptual Understanding Investigative Processes
  • Apply knowledge and conceptual understanding to a range of complex and challenging tasks.
  • Gather and interpret the meaning and significance of complex and challenging concepts.
  • Make links between concepts, principles and theories to find solutions in complex and challenging situations.
  • Explain systematically the mechanisms and processes of PCR.
  • Use scientific terminology to clearly communicate ideas and information related to PCR.

Assessment Task Outline

SA (Supervised Assessment)

Students will be given a supervised assessment (exam) at the end of the unit. The SA will consist of short answer responses, extended answer responses and response to stimulus material. Both quantitative and qualitative tasks will be included. The exam is recommended to be supervised and run for 60 minutes.

Evidence

Demonstrated evidence needs to include:

  • Reproduction, interpretation and linking of concepts and principles to find solutions in complex and challenging situations.
  • Explaining and justifying the mechanisms and process of PCR.
  • Analysing and evaluating complex scientific interrelationships.

Assessable Elements

KCU - Knowledge and Conceptual Understanding

Students should be given opportunities to:

  1. Recall and interpret concepts, theories and principles of Chemistry
  2. Describe and explain processes and phenomena of Chemistry
  3. Link and apply algorithms, concepts, theories and schema of Chemistry

IP - Investigative Processes

Students should be given opportunities to:

  1. Conduct and appraise chemical research tasks
  2. Operate chemical equipment and technology safely
  3. Use primary and secondary chemical data

EC - Evaluating and Concluding

Students should be given opportunities to:

  1. Determine, analyse and evaluate the chemical interrelationships involved in Chemistry
  2. Predict chemical outcomes and justify chemical conclusions and recommendations
  3. Communicate chemical information in a variety of ways

AV - Attitudes and Values

Students should be given opportunities to:

  1. Retain openness to new chemical ideas, and develop intellectual honesty, integrity, collegiality, cooperation and respect for evidence and ethical conduct
  2. Develop a level of sensitivity to the implications of chemistry for individuals and society and understand that chemistry is a human endeavour with consequent limitations
  3. Develop a thirst for chemical knowledge, become flexible and persistent learners and appreciate the need for lifelong learning