This lesson describes how the mechanisms involved in the selective reabsorption of solutes in the proximal convoluted tubule. The PowerPoint and accompanying resource have been designed to cover the first part of specification point 9.9 (iii) of the Edexcel A-level Biology B specification and builds on the knowledge gained in the previous lessons on the structure of the nephron and ultrafiltration. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the PCT and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water.

This fully-resourced lesson describes the effects of enzyme and substrate concentration on the rate of enzyme-catalysed reactions. The PowerPoint and accompanying resources are the third in a series of 4 lessons which cover the details of point 3.2 (a) of the CIE A-level Biology specification. 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 attained 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 come to recognise that this availability is the result of enzyme synthesis and enzyme degradation and a series of tasks will introduce the details of transcription and translation and therefore prepare them for the lessons in topic 6. Please note that this lesson explains the Biology behind the effect of concentration on enzyme-catalysed reactions and not the methodology involved in carrying out such an investigation as this is covered in a core practical lesson.

This lesson describes how to use and manipulate the magnification formula to calculate the magnification or the actual size in a range of units. The PowerPoint and accompanying resources have been designed to cover point 2.1.1 (e) of the OCR A-level Biology A specification and contains a number of quiz rounds as part of the competition that runs throughout all of the module 2.1.1 lessons The students are likely to have met the magnification formula at GCSE so this lesson has been written to build on that knowledge and to support them with more difficult questions when they have to calculate actual size without directly being given the magnification. A step by step guide is used to walk the students through the methodology and useful tips are provided. Students could be asked to calculate the actual size in millimetres, micrometres, nanometres or picometres so time is taken to ensure that they can convert between one and another.

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 explains the effects of temperature increases on enzyme activity and describes how to calculate the temperature coefficient. The PowerPoint and the accompanying resource are part of the second lesson in a series of 3, which cover the content detailed in point 2.1.4 (d) [i] of the OCR A-level Biology A specification and this lesson has been specifically planned to tie in with an earlier lesson covering 2.1.4 (a, b & c) 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 latter two in the PCR and photosynthesis are briefly described to prepare students for these lessons in modules 6 and 5. 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. The final part of the lesson introduces the Q10 temperature coefficient and students are challenged to apply this formula to calculate the value for a chemical reaction and a metabolic reaction to determine that enzyme-catalysed reactions have higher rates of reaction 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 is part of a lesson covering specification point 2.1.4 (d) [ii]

This lesson describes the light-dependent reactions of photosynthesis, focusing on the link to the light-independent reactions. The detailed PowerPoint and accompanying resources have been designed to cover the details included in point 5.7 of the Edexcel A-level Biology specification and therefore describes how light energy is trapped by exciting electrons in chlorophyll and the role of these electrons in generating ATP, reducing NADP in photophosphorylation and producing oxygen through photolysis of water. This is a topic which students tend to find difficult so this lesson has been intricately planned to walk them through each of the key reactions in the light-dependent stage. 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 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 cell structure 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 fashion. 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 in excess of 2.5 hours of allocated A-level teaching time to complete

This detailed lesson describes the gross and microscopic structure of the mammalian kidney. The engaging PowerPoint and accompanying resource have been designed to cover point 7.18 of the Edexcel International A-level Biology specification. The lesson was designed to tie in with the upcoming kidney lessons (7.19 - 7.21) on ultrafiltration, selective reabsorption and the control of mammalian plasma concentration and a common theme runs throughout to allow students to build their knowledge gradually and develop a deep understanding of this organ. Students will come to recognise the renal cortex and renal medulla as the two regions of the kidney and learn the parts of the nephron which are found in each of these regions. Time is taken to look at the vascular supply of this organ and specifically to explain how the renal artery divides into the afferent arterioles which carry blood towards the glomerulus and the efferent arterioles which carry the blood away. The main task of the lesson challenges the students to relate structure to function. Having been introduced to the names of each of the parts of the nephron, they have to use the details of the structures found at these parts to match the function. For example, they have to make the connection between the microvilli in the PCT as a sign that this part is involved in selective reabsorption.

This lesson describes the tests that detect reducing and non-reducing sugars and starch using Benedict’s solution and iodine/potassium iodide. The PowerPoint and accompanying resource are part of the last lesson in a series of 4 lessons which have been designed to cover the content of topic 1.2 (Carbohydrates) of the AQA A-level Biology specification. The lesson begins with an explanation of the difference between a qualitative and quantitative test so that the students recognise that the two tests described within this lesson indicate the presence of a substance but not how much. The students are likely to have met these tests at GCSE so this lesson has been planned to build on that knowledge and to add the knowledge needed at this level. A step by step guide walks the students through each stage of the tests for reducing and non-reducing sugars and application of knowledge questions and prior knowledge checks are included at appropriate points to ensure understanding is complete. Time is also taken to ensure that students understand the Science behind the results. The rest of the lesson focuses on the iodine test for starch and the students will learn that the colour change is the result of the movement of an ion into the amylose helix.

This lesson describes the chemical tests for proteins, reducing and non-reducing sugars, starch and lipids and explains how to interpret the results. The PowerPoint and accompanying resource have been designed to cover point 2.1.2 (q) of the OCR A-level Biology A specification. The lesson begins with an explanation of the difference between a qualitative and quantitative test so that the students recognise that the four tests described within this lesson indicate the presence of a substance but not how much. The students are likely to have met these tests at GCSE so this lesson has been planned to build on that knowledge and to add the knowledge needed at this level. A step by step guide walks the students through each stage of the tests for reducing and non-reducing sugars and application of knowledge questions and prior knowledge checks are included at appropriate points to ensure understanding is complete. Time is also taken to ensure that students understand the Science behind the results. The next part of the lesson focuses on the iodine test for starch and the students will learn that the colour change is the result of the movement of an ion into the amylose helix. The rest of the lesson describes the steps in the biuret test for proteins and the emulsion test for lipids. The students will learn that the addition of sodium hydroxide and then copper sulphate will result in a colour change from light blue to lilac if a protein is present and that following the addition of a sample to ethanol and then water, a cloudy emulsion is observed if a lipid is present.

This lesson describes how solutes are selectively reabsorbed in the proximal tubule. The PowerPoint and accompanying resource have been designed to cover the first part of specification point 7.20 of the Edexcel International A-level Biology specification and builds on the knowledge gained in the previous lessons on the microscopic structure of the nephron and ultrafiltration. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the PCT and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water.

This detailed lesson describes how urea is produced from excess amino acids and then removed from the bloodstream by ultrafiltration. The PowerPoint and accompanying resources have been designed to cover point 7.19 of the Edexcel International A-level Biology specification. The first part of the lesson describes how deamination and the ornithine cycle forms urea. Although the students are not required to know the details of the cycle, it is important that they are aware of how the product of deamination, ammonia, is converted into urea (and why). Moving forwards, the rest of the lesson has been written to allow the students to discover ultrafiltration as a particular function of the nehron and to be able to explain how the mechanisms found in the glomerulus and the Bowman’s capsule control the movement of small molecules out of the blood plasma. Key terminology is used throughout and students will learn how the combination of the capillary endothelium and the podocytes creates filtration slits that allow glucose, water, urea and ions through into the Bowman’s capsule but ensure that blood cells and plasma proteins remain in the bloodstream. A number of quiz competitions are used to introduce key terms and values in a fun and memorable way whilst understanding and prior knowledge checks allow the students to assess their understanding of the current topic and to challenge themselves to make links to earlier topics. The final task of the lesson challenges the students to apply their knowledge by recognising substances found in a urine sample that shouldn’t be present and to explain why this would cause a problem

This lesson explains how negative feedback control maintains systems within narrow limits and uses biological examples to describe the meaning of positive feedback. The PowerPoint and accompanying resources have been designed to cover points 7.11 (i) and (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but have been planned to provide important details for upcoming topics such as the importance of homeostasis during exercise and the depolarisation of a neurone. The normal ranges for blood glucose concentration, blood pH and body temperature are introduced at the start of the lesson to allow students to recognise that these aspects have to be maintained within narrow limits. A series of exam-style questions then challenge their recall of knowledge from topics 1 - 6 as well as earlier in topic 7 to explain why it’s important that each of these aspects is maintained within these limits. The students were introduced to homeostasis at GCSE, so this process is revisited and discussed, so that students are prepared for an upcoming lesson on exercise, as well as for the next part of the lesson on negative feedback control. Students will learn how this form of control reverses the original change and biological examples are used to emphasise the importance of this system for restoring levels to the limits (and the optimum). The remainder of the lesson explains how positive feedback differs from negative feedback as it increases the original change and the role of oxytocin in birth and the movement of sodium ions into a neurone are used to exemplify the action of this control system.

This lesson describes the function of transcription factors in eukaryotes and uses the lac operon to explain the control of protein production in a prokaryote. The detailed PowerPoint and accompanying resources have been designed to cover points 16.3 (b, c & d) as detailed in the CIE A-level Biology specification and also includes a description of how gibberellin breaks down DELLA protein repressors, allowing transcription to be promoted. This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 6, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promoter region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. Their understanding is then tested again with another example with oestrogen and the ER receptor. The final and main section of the lesson focuses on the lac operon and immediately an opportunity is taken to challenge their knowledge of biological molecules with a task where they have to spot the errors in a passage describing the formation and breakdown of this disaccharide. Students will be able to visualise the different structures that are found in this operon and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question.

This lesson describes the behaviour of chromosomes during meiosis, focusing on the events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover points 16.1 (a, d & e) of the CIE A-level Biology specification and explains how crossing over, the random assortment and the random fusion of haploid gametes leads to variation. In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to link to the two lessons on the cell cycle and the main stages of mitosis as covered in topic 5 and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This lesson describes the biuret and emulsion tests for proteins and lipids respectively and then acts as a revision lesson for topics 2.2 and 2.3. The engaging PowerPoint and accompanying resources have been designed to be taught at the end of topic 2 and uses a range of activities to challenge the students on their knowledge of that topic, but also covers the second part of point 2.1 (a) of the CIE A-level Biology specification when the qualitative tests are described. The first section of the lesson describes the steps in the biuret test and challenges the students on their recall of the reducing sugars and starch tests from topic 2.1 to recognise that this is a qualitative test that begins with the sample being in solution. The students will learn that the addition of sodium hydroxide and then copper sulphate will result in a colour change from light blue to lilac if a protein is present. The next part of the lesson uses exam-style questions with displayed mark schemes, understanding checks and quick quiz competitions to engage and motivate the students whilst they assess their understanding of this topic. The following concepts are tested during this lesson: The general structure of an amino acid The formation of dipeptides and polypeptides through condensation reactions The primary, secondary, tertiary and quaternary structure of a protein Biological examples of proteins and their specific actions (e.g. antibodies, enzymes, peptide hormones) Moving forwards, 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 and proteins. 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 the students are prepared for this molecule when it is met in topic 4 (cell membranes) This is an extensive lesson and it is estimated that it will take in excess of 2 hours of allocated teaching time to cover the detail and the different tasks

This lesson explains the effects of light intensity, carbon dioxide concentration and temperature (limiting factors) on the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover points 13.2 (a, b & c) of the CIE A-level Biology specification and also considers how knowledge of these limiting factors can be used to increase crop yields in the protected environment of a greenhouse. The lesson has been specifically written to tie in with the previous lessons in topic 13.1 which covered the structure of the chloroplast, the light-dependent reactions and the light-independent reactions. Exam-style questions are included throughout the lesson and these require the students to explain why light intensity is important for both reactions as well as challenging them on their ability to describe how the relative concentrations of GP, TP and RuBP would change as carbon dioxide concentration decreases. There are also links to previous topics such as enzymes when they are asked to explain why an increase in temperature above the optimum will limit the rate of photosynthesis. Step by step guides are included to support them to form some of the answers and mark schemes are always displayed so that they can quickly assess their understanding and address any misconceptions. The final part of the lesson provides details of the World’s largest rooftop greenhouse in Montreal and challenges their knowledge of related topics such as cellulose structure, pollination and biological control.

This lesson describes classification as a means of organising the variety of life based on relationships between organisms. The engaging PowerPoint and accompanying resource have been designed to cover point 4.14 (i) of the Edexcel International A-level Biology specification and focuses on the classification hierarchy where species is the lowest taxon but also describes the binomial naming system which uses the genus and species. The lesson also contains links to the next lesson 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.