This fully-resourced lesson explains how an enzyme’s specificity is related to their 3D structure and enables them to act as biological catalysts. The engaging PowerPoint and accompanying resources have been designed to cover the first parts of specification point 1.4.2 and considers the details of Fischer’s lock and key hypothesis and Koshland’s induced-fit model to deepen student understanding of the mechanism of enzyme action The lesson has been specifically planned to tie in with related topics that were previously covered such as protein structure and globular proteins. This prior knowledge is tested through a series of exam-style questions along with current understanding and mark schemes are included in the PowerPoint so that students can assess their answers. Students will learn that enzymes are large globular proteins which contain an active site that consists of a small number of amino acids. Emil Fischer’s lock and key hypothesis is introduced to enable students to recognise that their specificity is the result of an active site that is complementary in shape to a single type of substrate. Time is taken to discuss key details such as the control of the shape of the active site by the tertiary structure of the protein. The induced-fit model is described so students can understand how the enzyme-susbtrate complex is stabilised and then students are challenged to order the sequence of events in an enzyme-controlled reaction. The lesson finishes with a focus on ATP synthase and DNA polymerase so that students are aware of these important intracellular enzymes when learning about the details of respiration and DNA replication before they are challenged on their knowledge of carbohydrates, lipids and proteins from topics 1.2 - 1.4 as they have to recognise some extracellular digestive enzymes.

This lesson describes the structure of the chloroplast, focusing on the sites of the light-dependent and light-independent stages of photosynthesis. This fully-resourced lesson, which consists of an engaging PowerPoint and accompanying resources, has been designed to cover points 13.1 (a) & (b) of the CIE A-level Biology specification and has been specifically designed to introduce students to the grana and stroma as the site of the light-dependent and light-independent stages respectively before they are covered in greater detail in the lessons that are taught later in topic 13.1. Students were introduced to eukaryotic cells and their organelles in topic 1 so this lesson has been written to test and to build on that knowledge. A version of the quiz show POINTLESS runs throughout the lesson and this maintains engagement whilst challenging the students to recall the parts of the chloroplast based on a description which is related to their function. The following structures are covered in this lesson: double membrane thylakoids (grana) stroma intergranal lamellae starch grains chloroplast DNA and ribosomes Once each structure has been recalled, a range of activities are used to ensure that key details are understood such as the role of the thylakoid membranes in the light-dependent reactions and the importance of ATP and reduced NADP for the reduction of GP to TP in the Calvin cycle. Links to other topics are made throughout and this is exemplified by the final task of the lesson where students are challenged on their recall of the structure, properties and function of starch, as originally covered in topic 2.2

This lesson describes the light-dependent stage, focusing on photoactivation of chlorophyll, photolysis of water and the production of ATP and reduced NADP. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 13.1 (f) of the CIE A-level Biology specification and also describes cyclic and non-cyclic photophosphorylation The light-dependent stage of photosynthesis is a process which students can find difficult to understand in the necessary detail so this lesson has been planned to walk them through all of the key details. Time is taken to describe the roles of the major protein complexes that are embedded in the thylakoid membrane and this includes the two photosystems, the cytochrome proton pump and ATP synthase. A series of exam-style questions have been written that link to other biological topics in this course such as eukaryotic cell structures and membrane transport as well as application questions to challenge them to apply their understanding. Some of these resources have been differentiated to allow students of differing abilities to access the work and to be pushed at the same time. Students will learn that there are two pathways that the electron can take from PSI and at the completion of the two tasks which describe each of these pathways, they will understand how ATP is generated in non-cyclic and cyclic photophosphorylation. The final task of the lesson asks them to compare these two forms of photophosphorylation to check that they understand when photolysis is involved and reduced NADP is formed. Due to the detail included in this lesson, it is estimated that it will take up to 3 hours of allocated A-level teaching time to complete.

This lesson describes and explains how temperature affects enzyme activity. The PowerPoint and the accompanying resource are part of the 1st lesson in a series of 3 which cover the content detailed in point 1.5 (iv) of the Edexcel A-level Biology B specification and this lesson has been specifically planned to tie in with the previous lesson covering 1.5 (i, ii & iii) where the structure, properties 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 latter two in the PCR and photosynthesis are briefly described to prepare students for these lessons in topics 7 and 5. Moving forwards, the rest 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. Please note that this lesson has been designed specifically to explain the relationship between the change in temperature and the rate of enzyme activity in a reaction and not the practical skills that would be covered in a core practical lesson

This fully-resourced lesson describes how enzyme and substrate concentration can affect the rate of an enzyme-controlled reaction. The PowerPoint and accompanying resources are the 4th in a series of 5 lessons which cover the detail of point 1.4.2 of the AQA A-level Biology specification. Transcription and translation are also introduced and therefore this lesson could be used in preparation for the detailed lessons in topic 4.2. The first part of the lesson describes how an increase in substrate concentration will affect the rate of reaction when a fixed concentration of enzyme is used. Time is taken to introduce limiting factors and students will be challenged to identify substrate concentration as the limiting factor before the maximum rate is achieved and then they are given discussion time to identify the possible factors after this point. A series of exam-style questions are used throughout the lesson and the mark schemes are displayed to allow the students to assess their understanding and for any misconceptions to be immediately addressed. Moving forwards, the students have to use their knowledge of substrate concentration to construct a graph to represent the relationship between enzyme concentration and rate of reaction and they have to explain the different sections of the graph and identify the limiting factors. The final section of the lesson describes how the availability of enzymes is controlled in living organisms. Students will recognise that this availability is the result of enzyme synthesis and enzyme degradation and a number of prior knowledge checks challenge students on their knowledge of proteins as covered in topic 1.4.1 Please note that this lesson explains the Biology behind the effect of concentration on enzyme-controlled reactions and not the methodology involved in carrying out such an investigation as this is covered in a core practical lesson.

This fully-resourced lesson explains why the speed of transmission along myelinated axons is greater than along non-myelinated axons. The PowerPoint and accompanying resources have been designed to cover point 9.5 (iii) of the Edexcel A-level Biology B specification which states that students should understand the role of saltatory conduction in the transmission of action potentials. A wide range of activities have been written into this resource to maintain the motivation of the students whilst ensuring that the detail is covered in real depth. Interspersed with the activities are understanding checks and prior knowledge checks to allow the students to not only assess their understanding of the current topic but also challenge themselves to make links to earlier topics such as the movement of ions across membranes and biological molecules. Time at the end of the lesson is also given to future knowledge such as the involvement of autonomic motor neurones in the stimulation of involuntary muscles. Over the course of the lesson, students will learn and discover the myelin sheath wrapped around the axons of sensory and motor neurones allows these neurones to conduct impulses quickly between receptors and the CNS and between the CNS and effectors. There is a focus on this myelin sheath and specifically how the insulation is not complete all the way along which leaves gaps known as the nodes of Ranvier which allow the entry and exit of ions. Saltatory conduction is poorly understood (and explained) by a lot of students so time is taken to look at the way that the action potential jumps between the nodes and this is explained further by reference to local currents. The rest of the lesson focuses on the other two factors which are axon diameter and temperature and students are challenged to discover these two by focusing on the vampire squid.

This detailed lesson describes the formation and effects of excitatory and inhibitory postsynaptic potentials . The PowerPoint has been designed to cover point 9.5 (v) of the Edexcel A-level Biology B specification. This is a topic which is generally poorly understood by students or brushed over so considerable time has been taken to design the activities to motivate the students so that the content is memorable whilst still being covered in detail. Links are continually made to earlier topics in this topic such as synapses and generator potentials but also to topics covered in the previous year. The lesson begins by challenging the students to recognise a description of generator potential and they will then discover that this is also known as an EPSP. Students will recall that a small depolarisation may not lead to the opening of the voltage gated channels and therefore the full depolarisation which is needed for the initiation of an action potential and will discuss how this problem could be overcome. Lots of discussion points like this are included in the lesson to encourage the students to challenge and debate why a particular process of mechanism occurs. Students will therefore learn that EPSPs can be combined and this is known as summation. A quiz round is used to introduce temporal and spatial summation. Moving forwards, students are presented with a number of examples where they have to decide why type of summation is involved. Again, the lesson has been written to include real-life examples such as chronic pain conditions so the chances of the content sticking is increased. The final part of the lesson introduces IPSPs and the effect of these on summation and action potentials is discussed.

This fully-resourced lesson describes the ultrastructure of eukaryotic cells and the functions of the different cellular components. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 2.1.1 (g) & (i) of the OCR A-level Biology A specification and therefore also describes the interrelationship between the organelles involved in the production and secretion of proteins. As cells are the building blocks of living organisms, it makes sense that they would be heavily involved in all 6 modules in the OCR course and intricate planning has ensured that links to the lessons earlier in module 2.1.1 are made as well as to the upcoming modules. The lesson uses a wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, to maintain motivation and engagement whilst describing the relationship between the structure and function of the following organelles: nucleus nucleolus centrioles ribosomes rough endoplasmic reticulum Golgi apparatus lysosomes smooth endoplasmic reticulum mitochondria cell surface membrane vacuole chloroplasts plasmodesmata Details of the cilia and flagella are covered in the lesson on the importance of the cytoskeleton. All of the worksheets have been differentiated to support students of differing abilities whilst maintaining challenge Due to the detail that is included in this lesson, it is estimated that it will take in excess of 3 hours of allocated A-level teaching time to go through all of the tasks

This lesson describes biodiversity and explains how it can be calculated within a species, a habitat and how it can be compared between habitats. The detailed PowerPoint and accompanying resources have been designed to cover points 4.16, 4.17 & 4.18 in unit 2 of the Edexcel International A-level Biology specification and the meaning of endemism is also explained. A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise key terms from their definitions. This quiz will introduce species, population, biodiversity, endemic, heterozygote and natural selection and each of these terms is put into context once introduced. Once biodiversity has been revealed, the students will learn that they are expected to be able to measure biodiversity within a habitat, within a species and within different habitats so that they can be compared. The rest of the lesson uses step by step guides, discussion points and selected tasks to demonstrate how to determine species richness, the heterozygosity index and an index of diversity. Students are challenged with a range of exam-style questions where they have to apply their knowledge and all mark schemes are displayed and clearly explained within the PowerPoint to allow students to assess their understanding and address any misconceptions if they arise.

This fully-resourced lesson describes the structural and physiological differences between fast and slow twitch muscle fibres. The detailed PowerPoint and accompanying resources have been designed to cover point 7.10 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and due to the obvious links, this lesson also challenges the students on their knowledge of respiration from earlier in topic 7 and cell structures and biological molecules from topics 1, 2 and 3 The following structural and physiological characteristics are covered over the course of this lesson: Reliance on the aerobic or anaerobic pathways to generate ATP Resistance to fatigue mitochondrial density capillary density myoglobin content (and colour) fibre diameter phosphocreatine content glycogen content A wide variety of tasks are used to cover this content and include knowledge recall and application of knowledge exam-style questions with fully-displayed mark schemes as well as quick quiz competitions to maintain motivation and engagement. This lesson has been specifically planned to tie in with the previous lesson in this topic covering the contraction of skeletal muscles by the sliding filament mechanism

This lesson describes the overall reaction of aerobic respiration, introducing the 4 stages before the finer details are covered in the upcoming lessons. The engaging PowerPoint and accompanying resource have been designed to cover points 7.1 (i) and (ii) of the Edexcel International A-level Biology specification and explains how each step in this many-stepped process is catalysed by a specific intracellular enzyme. The lesson begins with an introduction to glycolysis and students will learn how this first stage of aerobic respiration is also the first stage when oxygen is not present. This stage involves 10 reactions and an opportunity is taken to explain how each of these reactions is catalysed by a different, specific intracellular enzyme. A version of “GUESS WHO” challenges students to use a series of structural clues to whittle the 6 organelles down to just the mitochondrion so that they can learn how the other three stages take place inside this organelle. Moving forwards, the key components of the organelle are identified on a diagram. Students are introduced to the stages of respiration so that they can make a link to the parts of the cell and the mitochondria where each stage occurs. Students will learn that the presence of decarboxylase and dehydrogenase enzymes in the matrix along with coenzymes and oxaloacetate allows the link reaction and the Krebs cycle to run and that these stages produce the waste product of carbon dioxide. Finally, time is taken to introduce the electron transport chain and the enzyme, ATP synthase, so that students can begin to understand how the flow of protons across the inner membrane results in the production of ATP and the the formation of water when oxygen acts as the final electron acceptor.

This detailed lesson describes the roles of the link reaction and the Krebs cycle in the complete oxidation of glucose which occur in the mitochondrial matrix. The PowerPoint and the accompanying resource have been designed to cover point 7.3 of the Edexcel International A-level Biology specification and includes descriptions of the formation of carbon dioxide, ATP, reduced NAD and FAD The lesson begins with a challenge, where the students have to recall the details of glycolysis in order to form the word matrix. This introduces the key point that these two stages occur in this part of the mitochondria and time is taken to explain why the reactions occur in the matrix as opposed to the cytoplasm like glycolysis. Moving forwards, the Link reaction is covered in 5 detailed bullet points and students have to add the key information to these points using their prior knowledge as well as knowledge provided in terms of NAD. The students will recognise that this reaction occurs twice per molecule of glucose and a quick quiz competition is used to test their understanding of the numbers of the different products of this stage. This is just one of the range of methods that are used to check understanding and all answers are explained to allow students to assess their progress. The rest of the lesson focuses on the Krebs cycle. In line with the detail of the specification, students will understand how decarboxylation and dehydrogenation reactions result in the regeneration of the oxaloacetate

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 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 role of barriers in protecting the body from infection by pathogens when entering the body by the major routes. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 6.11 (i) & (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and describe the following barriers: skin key steps of the blood clotting process mucous membranes stomach acid vaginal and skin flora There are clear links to topics 1, 2 and 3 in each of these barriers, so time is taken to consider these during 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 blood clotting, protein structure, key terminology and the epithelium that lines the different parts of the airways. All of the exam-style questions and tasks have mark schemes that are embedded in the PowerPoint and a number of them have been differentiated to allow students of differing abilities to access the work.