This lesson explains the effects of temperature on the rate of enzyme activity and includes examples in plants, animals and microorganisms. The PowerPoint and the accompanying resource have been designed to cover point 5.16 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and this lesson has been specifically planned to tie in with a lesson in topic 2 where the roles and mechanism of action of enzymes were introduced. The lesson begins by challenging the students to recognise optimum as a key term from its 6 synonyms that are shown on the board. Time is taken to ensure that the students understand that the optimum temperature is the temperature at which the most enzyme-product complexes are produced per second and therefore the temperature at which the rate of an enzyme-controlled reaction works at its maximum. The optimum temperatures of DNA polymerase in humans and in a thermophilic bacteria and RUBISCO in a tomato plant are used to demonstrate how different enzymes have different optimum temperatures and the roles of the former in the PCR is briefly described to prepare students for this lesson in topic 6. Moving forwards, the next part of the lesson focuses on enzyme activity at temperatures below the optimum and at temperatures above the optimum. Students will understand that increasing the temperature increases the kinetic energy of the enzyme and substrate molecules, and this increases the likelihood of successful collisions and the production of enzyme-substrate and enzyme-product complexes. When considering the effect of increasing the temperature above the optimum, continual references are made to the previous lesson and the control of the shape of the active site by the tertiary structure. Students will be able to describe how the hydrogen and ionic bonds in the tertiary structure are broken by the vibrations associated with higher temperatures and are challenged to complete the graph to show how the rate of reaction decreases to 0 when the enzyme has denatured.

This lesson describes the steps in the emulsion test for lipids and then uses a range of tasks to challenge the students on their knowledge of topic 1.3. The engaging PowerPoint and accompanying resource are part of the last lesson in a series of 3 lessons which have been designed to cover the content of point 1.3 (lipids) of the AQA A-level Biology specification. The first part of the lesson describes the key steps in the emulsion test for lipids, and states the positive result for this test. There is a focus on the need to mix the sample with ethanol, which is a distinctive difference to the tests for reducing sugars and starch. The remainder of the lesson uses exam-style questions with mark schemes embedded in the PowerPoint, understanding checks, guided discussion points and quick quiz competitions to challenge the following specification points: The structure of a triglyceride The relationship between triglyceride property and function The hydrophilic and hydrophobic nature of the phospholipid The phospholipid bilayer of the cell membrane Cholesterol is also introduced so that students are prepared for this molecule when it is met in topic 2.3 (cell membranes)

This lesson describes the principles of hormone production by endocrine glands and the two modes of action on target cells. The detailed PowerPoint and accompanying resources have been primarily designed to cover points 9.2 (i) & (ii) of the Edexcel A-level Biology B specification but can also be used as a revision tool to check on their knowledge of topics like biological molecules and transcription factors Students should have a base knowledge of the endocrine system from GCSE so this lesson has been planned to build on that knowledge and to add the detail needed at this level. The lesson begins by challenging this knowledge to check that they understand that endocrine glands secrete these hormones directly into the blood. Students will learn that most of the secreted hormones are peptide (or protein) hormones and a series of exam-style questions are used to challenge them on their recall of the structure of insulin as well as to apply their knowledge to questions about glucagon. Moving forwards, the students are reminded that hormones have target cells that have specific receptor sites on their membrane. The relationship between a peptide hormone as a first messenger and a second messenger on the inside of the cell is described to allow students to understand how the activation of cyclic AMP triggers a cascade of events on the inside of the cell. The rest of the lesson focuses on steroid hormones and specifically their ability to pass through the membrane of a cell and to bind to transcription factors, as exemplified by oestrogen.

This lesson outlines the need for energy in living organisms, and describes how ATP is formed by phosphorylation in respiration and photosynthesis. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover points 12.1 (a, b, c & e) of the CIE A-level Biology specification but can be used as a revision of topics 1, 4 and 6 as the students knowledge of cell structure, membrane transport and ATP is constantly challenged. As this is the first lesson in topic 12 (respiration), it has been specifically planned to act as an introduction to this cellular reaction and provides important details about glycolysis, the Krebs cycle and oxidative phosphorylation that will support the students to make significant progress when these stages are covered during individual lessons. Photophosphorylation is also introduced so students are prepared for the light-dependent reaction of photosynthesis in topic 13. The main focus of the start of the lesson is the demonstration of the need for energy in a variety of reactions that occur in living organisms. Students met ATP in topics 1 and 6, so a spot the errors task is used to check on their recall of the structure and function of this molecule. This will act to remind them that the release of energy from the hydrolysis of ATP can be coupled to energy-driven reactions in the cell such as active transport and a series of exam-style questions are used to challenge them on their knowledge of this form of membrane transport. They will also see how energy is needed for protein synthesis and DNA replication and the maintenance of resting potential, before more questions challenge them to apply their knowledge of cell structure and transport to explain how it is needed during the events at a synapse. The rest of the lesson focuses on the production of ATP by substrate-level, oxidative and photophosphorylation and the students will learn when ATP is formed by each of these reactions and will see how the electron transport chain in the membranes in the mitochondria and chloroplast is involved

This fully-resourced lesson describes how allopatric or sympatric speciation may result from geographical, ecological or behavioural separation. The engaging PowerPoint and accompanying resources have been designed to cover point 17.3 [c] of the ICE A-level Biology specification and uses actual biological examples to increase the relevance and likelihood of understanding The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This lesson describes the meaning of ecological terms and explains how biotic and abiotic factors control the distribution of organisms in a habitat. The engaging PowerPoint and accompanying resources have been designed to cover points 5.11, 5.12 and 5.13 in unit 4 of the Edexcel International A-level Biology (Salters Nuffield) specification and therefore cover the biological definitions of ecosystem, community, population and habitat. A quiz round called REVERSE Biology Bingo runs throughout the lesson and challenges students to recognise the following key terms from descriptions called out by the bingo caller: community ecosystem abiotic factor photosynthesis respiratory substrate biomass calorimetry distribution niche The ultimate aim of this quiz format is to support the students to understand that any sugars produced by photosynthesis that are not used as respiratory substrates are used to form biological molecules that form the biomass of a plant and that this can be estimated using calorimetry. Links are made to photosynthesis and net primary productivity as these will be met later in topic 5 as well as challenging their prior knowledge of adaptations, heterozygosity index classification and biological molecules. The final part of the lesson uses an exam-style question to get the students to recognise that biotic and abiotic factors control the distribution of organisms in a habitat and to recall the concept of niche.

This fully-resourced lesson describes the process of contraction of skeletal muscle in terms of the sliding filament theory. The PowerPoint and accompanying resources have been designed to cover point 7.11 of the Edexcel International A-level Biology specification and includes descriptions of the role of actin, myosin, troponin, tropomyosin, calcium ions, ATP and ATPase. The lesson begins with a study of the structure of the thick and thin filaments. Students will recognise that the protruding heads of the myosin molecule are mobile and this enables this protein to bind to the binding sites when they are exposed on actin. This leads into the introduction of troponin and tropomyosin and key details about the binding of calcium to this complex is explained. Moving forwards, students are encouraged to discuss possible reasons that can explain how the sarcomere narrows during contraction when the filaments remain the same length. This main part of the lesson goes through the main steps of the sliding filament model of muscle contraction and the critical roles of the calcium ions and ATP are discussed. The final task of the lesson challenges the students to apply their knowledge by describing the immediate effect on muscle contraction when one of the elements doesn’t function correctly. This lesson has been written to tie in with the previous lesson on the structure of skeletal muscle fibre (point 7.10)

This lesson describes the extracellular action of peptide hormones and the role played by steroid hormones in binding to DNA transcription factors. The detailed PowerPoint and accompanying resources have been designed to cover point 7.22 of the Edexcel International A-level Biology specification and focuses on the differing effects of these two types of hormones on their target cells Students should have a base knowledge of the endocrine system from GCSE so this lesson has been planned to build on that knowledge and to add the detail needed at this level. The lesson begins by challenging this knowledge to check that they understand that endocrine glands secrete these hormones directly into the blood. Students will learn that most of the secreted hormones are peptide (or protein) hormones and a series of exam-style questions are used to challenge them on their recall of the structure of insulin as well as to apply their knowledge to questions about glucagon. Moving forwards, the students are reminded that hormones have target cells that have specific receptor sites on their membrane. The relationship between a peptide hormone as a first messenger and a second messenger on the inside of the cell is covered in detail in an upcoming lesson but students are briefly introduced to G proteins and cyclic AMP so they are prepared. The rest of the lesson focuses on steroid hormones and specifically their ability to pass through the membrane of a cell and to bind to transcription factors, as exemplified by oestrogen. Students covered transcription and the control of gene expression in topics 2 and 3 so the final tasks challenge their recall of these concepts

This lesson describes how the electron transport chain and the chemiosmosis are involved in the synthesis of ATP by oxidative phosphorylation. The PowerPoint has been designed to cover point 7.4 of the Edexcel International A-level Biology specification and also looks at the role of the enzyme, ATP synthase. The lesson begins with a discussion about the starting point of the reaction. In the previous stages, the starting molecule was the final product of the last stage but in this stage, it is the reduced coenzymes which release their hydrogen atoms. Moving forwards, the process of oxidative phosphorylation is covered in 7 steps and at each point, key facts are discussed and explored in detail to enable a deep understanding to be developed. Students will see how the proton gradient is created and that the flow of protons down the channel associated with ATP synthase results in a conformational change and the addition of phosphate groups to ADP. Understanding checks are included throughout the lesson to enable the students to assess their progress. This lesson has been specifically written to tie in with the other uploaded lessons on glycolysis, the link reaction and Krebs cycle.

This lesson reminds students of the meaning of homeostasis and describes the how thermoregulation maintains the body in dynamic equilibrium during exercise. The PowerPoint has been designed to cover point 7.17 of the Edexcel International A-level Biology specification. Students were introduced to homeostasis at GCSE and this lesson has been written to build on that knowledge and to add the key detail needed at this level. Focusing on the three main parts of a homeostatic control system, the students will learn about the role of the internal and peripheral thermoreceptors, the thermoregulatory centre in the hypothalamus and the range of effectors which bring about the responses to restore optimum levels. The following responses are covered in this lesson: Vasodilation Increased sweating Body hairs In each case, time is taken to challenge students on their ability to make links to related topics such as the arterioles involved in the redistribution of blood and the high specific latent heat of vaporisation of water.

This lesson describes how to calculate the cardiac output as the product of stroke volume and the heart rate. The PowerPoint and accompanying resource have been designed to cover point 7.13 (i) of the Edexcel International A-level Biology specification. The lesson begins by challenging the students to recognise that the left ventricle has the most muscular wall of all of the heart chambers. This allows the stroke volume to be introduced as the volume of blood ejected from the left ventricle each heart beat and then a quiz competition is used to introduce normative values for the stroke volume and the heart rate. Moving forwards, students will learn that the cardiac output is the product of the stroke volume and the heart rate. A series of exam-style questions will challenge the students to use this formula and to manipulate it and to work out the percentage change. The final part of the lesson looks at the adaptation of the heart to aerobic training in the form of cardiac hypertrophy and then the students are challenged to work out how this would affect the stroke volume, the cardiac output and the resting heart rate.

This lesson describes how the sensory receptors of the nervous system detect stimuli by transducing different forms of energy into electrical energy. The PowerPoint has been designed to cover the content of the 1st part of specification point 8.5 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and acts as an introduction to the next lesson where the roles of the rod cells in the retina is described. The lesson begins by using a quiz to get the students to recognise the range of stimuli which can be detected by receptors. This leads into a task where the students have to form 4 sentences to detail the stimuli which are detected by certain receptors and the energy conversion that happen as a result. Students will be introduced to the idea of a transducer and learn that receptors always convert to electrical energy which is the generator potential. The remainder of the lesson focuses on the Pacinian corpuscle and how this responds to pressure on the skin, resulting in the opening of the sodium channels and the flow of sodium ions into the neurone to cause depolarisation.

This fully-resourced lesson describes the major routes that pathogens take when entering the body and the body’s barriers to this infection. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 6.7 (i) & (ii) of the Edexcel International A-level Biology specification and includes descriptions of the following barriers: skin the blood clotting process mucous membranes stomach acid vaginal acid and flora skin and gut flora wax in the ear canal There are clear links to topics 1, 2 and 3 in each of these barriers, so these are considered and discussed during each of the descriptions. For example, the presence of keratin in the cytoplasm of the skin cells allows the student knowledge of the properties of this fibrous protein to be checked. Other topics that are revisited during this lesson include protein structure, key terminology and the epithelium that lines the different parts of the airways. All of the exam-style questions have mark schemes that are embedded into the PowerPoint and a number of the tasks have been differentiated to allow students of differing abilities to access the work.

This lesson describes how the critical evaluation of new data by the scientific community leads to new taxonomic groupings, like the three domains of life. The detailed PowerPoint and accompanying resources have been designed to cover point 4.6 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a previous lesson, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank. Moving forwards, the rest of the lesson describes how molecular phylogeny uses other molecules and that these are compared between species for classification purposes. One of these is a protein called cytochrome which is involved in respiration and can be compared in terms of primary structure to determine relationships. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code (as covered in topic 2) and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes the classification system, focusing on the biological classification of a species and the 7 taxa found above this lowest taxon. The engaging PowerPoint and accompanying resource have been designed to cover point 4.6 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and also describes the binomial naming system which uses the genus and species. The lesson also contains links to upcoming lessons where molecular phylogeny is described and the three-domain system is covered in greater detail with a focus on the results of Carl Woese’s rRNA study The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a horse and a donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Moving forwards, students will learn that classification is a means of organising the variety of life based on relationships between organisms using differences and similarities in phenotypes and in genotypes and is built around the species concept and that in the modern-day classification hierarchy, species is the lowest taxon. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn (or recall) the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system.