#7:Teacher notes
This true-or-false activity could be used as a plenary or revision exercise on enzymes, or at the start of the lesson to gauge students’ existing knowledge of the subject matter. Coloured traffic light cards (red = false, yellow = don’t know, green = true) could be used to make this a whole-class exercise.
#9:Teacher notes
This illustration contains several discussion points relating to enzymes, including:
Thermostat
Different enzymes have different optimum temperatures. Beyond their optimum temperature enzymes denature (breakdown). The thermostat in the illustration is set to a high temperature, and most of the enzymes seem uncomfortably hot.
Arguments
The shape of an enzyme’s active site determines which reactants it can bond with. In this illustration, incompatible enzyme–reactant pairs are shown either arguing or ignoring each other.
‘The happy couple’
Enzymes and reactants that are compatible are said to fit together like a ‘lock and key’. The happy couple shown in the bottom left of the illustration have corresponding shapes, and seem to be reacting well to each other in the warm environment.
#10:Photo credit: JC Revy / Science Photo Library
The image shows a molecular computer graphics image of ribonuclease A, an enzyme involved in the destruction of messenger RNA (mRNA) in the cytoplasm of bacteria. At left is its substrate, shifted away from the active site. Enzymes are biological catalysts, proteins that speed up the rates of reactions within cells. Each enzyme is specific for a particular reaction; interaction occurs (typically as a weak bond) between an active site on the enzyme & a reactant (or substrate) due to the arrangement of mutually attractive groups of atoms. This image displays the molecular surface (blue) & polypeptide chain: colours are used to represent the polarity of constituent amino acids.
#12:Teacher notes
This four-stage animation demonstrates the principles of the ‘lock and key’ model. While showing the animation, the specific shape of the active site could be highlighted.
Suitable prompts could include:
What is special about the shape of the active site?
Is the enzyme the ‘lock’ or the ‘key’?
#13:Teacher notes
See the ‘Energy Transfer’ and ‘Rates of Reaction’ chemistry presentations for more information on activation energy.
#16:Teacher notes
This five-stage animation could be used as a precursor to running the experiment in the lab, or as a revision exercise.
#17:Teacher notes
This four-stage animation shows how competitive and non-competitive inhibitors block the action of enzymes by either binding to, or altering the shape of, their active site.
#18:Teacher notes
This matching activity could be used as a plenary or revision exercise on enzymes. Students could be asked to complete the questions in their books and the activity could be concluded by the completion on the IWB.
#22:Teacher notes
This activity could be used to check students’ understanding of chemical digestion.
#25:Teacher notes
See the ‘Animal and Plant Cells’ presentation for more information about mitochondria and respiration.
#27:Teacher notes
This illustration contains several discussion points relating to items made using enzymes, including:
Baby food: Proteases such as trypsin are used to predigest the protein in baby foods.
Baking (bread): Fungal enzymes are used to catalyze the breakdown of starch into sugar. The enzymes also produce carbon dioxide gas, which makes the dough rise.
Biological detergent (washing powder): Proteases, amylases and lipases are used to remove protein, starch and oily stains from clothes.
Brewing (beer): Proteases in barley are released as it is fermented during beer production. The enzymes break-down starch, carbohydrases and proteins, and clarify stored beers.
Confectionary (chocolates): Enzymes are used to make soft-centred chocolates.
Dairy products (cheese): Rennet (an enzyme from calves’ stomachs) is used to coagulate milk during cheese production, separating the curd (solids) from the whey (liquid). Lipases are used to enhance the flavour and ripening of blue cheeses, and lactases are used to break down-lactose into glucose and galactose.
Fruit juice: Enzymes that act on cellulose reduce the cloudiness of fruit juices.
Paper (penicillin box): Proteases and cellulases are used to soften and smooth pulped fibres during paper manufacture
Photography: Proteases are used to dissolve gelatin from waste film, allowing its silver content to be recovered and recycled.
Rubber (place mat in high chair): Catalase is used to convert latex into foam rubber.
#28:Teacher notes
This three-stage animation shows how enzymes are used in breadmaking. Suitable prompts could include:
What happens to the amylase and invertase during the baking process?
What is the name of the gas that the yeast produce during fermentation?
#29:Teacher notes
This activity could be used as a precursor to a wider discussion on drugs use and abuse.
See the GCSE Science (Biology) ‘Drug Use and Abuse’ presentation for more information on alcohol.
#35:Teacher notes
Appropriately coloured voting cards could be used with this classification activity to increase class participation.
#40:Teacher notes
This matching activity could be used as a plenary or revision exercise on enzymes. Students could be asked to complete the questions in their books and the activity could be concluded by the completion on the IWB.
#41:Teacher notes
This activity could be used to check students’ understanding of the lock and key model.
#42:Teacher notes
This multiple-choice quiz could be used as a plenary activity to assess students’ understanding of enzymes. The questions can be skipped through without answering by clicking “next”. Students could be asked to complete the questions in their books and the activity could be concluded by the completion on the IWB.
