This detailed lesson describes the different levels of protein structure and focuses on the bonds that hold these molecules in shape. Both the engaging PowerPoint and accompanying resources have been designed to cover specification point 2.3 (b) of the CIE International A-level Biology course and makes continual links to previous lessons such as amino acids & peptide bonds as well as to upcoming lessons like enzymes and antibodies. The start of the lesson focuses on the formation of a peptide bond during a condensation reaction so that students can understand how a dipeptide is formed and therefore how a polypeptide forms when multiple reactions occur. The main part of the lesson describes the different levels of protein structure. A step by step guide is used to demonstrate how the sequences of bases in a gene acts as a template to form a sequence of codons on a mRNA strand and how this is translated into a particular sequence of amino acids known as the primary structure. The students are then challenged to apply their understanding of this process by using three more gene sequences to work out three primary structures and recognise how different genes lead to different sequences. Moving forwards, students will learn how the order of amino acids in the primary structure determines the shape of the protein molecule, through its secondary, tertiary and quaternary structure and time is taken to consider the details of each of these. There is a particular focus on the different bonds that hold the 3D shape firmly in place and a quick quiz round then introduces the importance of this shape as exemplified by enzymes, antibodies and hormones. Students will see the differences between globular and fibrous protein and again biological examples are used to increase relevance. The lesson concludes with one final quiz round called STRUC by NUMBERS where the students have to use their understanding of the protein structures to calculate a numerical answer.

This lesson describes how the relationship between the different properties of water and its roles in living organisms. The engaging PowerPoint has been designed to cover specification point 2.3 (d) of the CIE International A-level Biology course. Hydrolysis reactions have been a recurring theme throughout topic 2, so the start of this lesson challenges the students to recognise the definition when only a single word is shown: water. Students will also recall the meaning of a condensation reaction. Moving forwards, the rest of the lesson focuses on the relationship between the structure and properties of water, beginning with its role as an important solvent. The lesson has been specifically written to make links to future topics and this is exemplified by the transport of water along the xylem in plants which is covered in topic 7. The next section focuses on the high latent heat of vaporisation and heat capacity of water and these properties are put into biological context using thermoregulation and the maintenance of a stable environment for aquatic animals. The lesson finishes with an explanation of the polar nature of water, a particularly important property that needs to be well understood for a number of upcoming topics, such as cell membranes.

This lesson describes the structure of an amino acid and the formation and breakage of a peptide bond. The PowerPoint has been designed to cover specification point 2.3 (a) of the CIE International A-level Biology course and provides a clear introduction to the following lesson on the formation of dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide. Moving forwards, students are given discussion time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference. Students will be introduced to the existence of hydrophobic and hydrophilic R groups so that they are able to apply this knowledge in future lessons where structure and shape is considered. Some time is also given to look at cysteine in greater detail due to the presence of sulfur atoms and once again a link is made to disulfide bridges for upcoming lessons. Another quiz round called LINK TO THE FUTURE will allow the students to recognise the roles performed by amino acids in the later part of the course such as translation and in the formation of dipeptides. The lesson concludes with a task that describes the breakage of the peptide bonds during hydrolysis reactions.

This fully-resourced lesson describes the non-specific responses of the body to infection and includes details of phagocytosis, inflammation and interferon release. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover the content of point 6.7 of the Pearson Edexcel A-level Biology A specification but topics including antigen-presentation are also introduced to prepare students for upcoming lessons on the immune response (6.8 & 6.9). At the start of the lesson, the students are challenged to recall that cytosis is a suffix associated with transport mechanisms and this introduces phagocytosis as a form of endocytosis which takes in pathogens and foreign particles. This emphasis on key terminology runs throughout the course of the lesson and students are encouraged to consider how the start or end of a word can be used to determine meaning. The process of phagocytosis is then split into 5 key steps and time is taken to discuss the role of opsonins as well as the fusion of lysosomes and the release of lysozymes. A series of application questions are used to challenge the students on their ability to make links to related topics including an understanding of how the hydrolysis of the peptidoglycan wall of a bacteria results in lysis. Students will be able to distinguish between neutrophils and monocytes from a diagram and at this point, the role of macrophages and dendritic cells as antigen-presenting cells is described so that it can be used in the next lesson. The importance of cell signalling for an effective immune response is discussed and the rest of the lesson focuses on the release of two chemicals - interferons and histamine. During the interferon section, references are made to a previous lesson on HIV structure and action so students can understand how the release of these signalling proteins helps neighbouring cells to heighten their anti-viral defences. A step by step guide is used to describe the release of histamine in the inflammatory response and the final task challenges students to use this support to form a detailed answer regarding the steps in inflammation.

This fully-resourced lesson describes how phenotype is the result of an interaction between genotype and the environment and can be affected by multiple alleles at many gene loci. The engaging PowerPoint and accompanying resources have been primarily designed to cover points 3.14 (i) & 3.15 of the Pearson Edexcel A-level Biology A specification but also includes activities to challenge the students on previous concepts in topics 3 and 2. The students begin the lesson by having to identify phenotype and species from their respective definitions so that a discussion can be encouraged where they will recognise that phenotypic variation within a species is due to both genetic and environmental factors. The main part of the the lesson focuses on these genetic factors, and describes how mutation and the events of meiosis contribute to this variation. A range of activities, which include exam-style questions and quick quiz rounds, are used to challenge the students on their knowledge and understanding of substitution mutations, deletions, insertions, the genetic code, crossing over and independent assortment. Moving forwards, the concept of multiple alleles is introduced and students will learn how the presence of more than 2 alleles at a locus increases the number of phenotypic variants. Another quick quiz round is used to introduce polygenic inheritance and the link is made between this inheritance of genes at a number of loci as an example of continuous variation. The final part of the lesson describes a few examples where environmental factors affect phenotype, such as chlorosis in plants. As this is the final lesson in topic 3, the numerous activities can be used for revision purposes and to show the links between different biological topics.

This engaging lesson describes how the structure and properties of phospholipids relate to their functions in cell membranes. The PowerPoint has been designed to cover point 1.2 (iv) as detailed in the Edexcel A-level Biology B specification and includes regular references to the previous lesson on triglycerides to check on knowledge and understanding The role of a phospholipid in a cell membrane provides the backbone to the whole lesson. A quick quiz round called family affair, challenges the students to use their knowledge of the structure of a triglyceride to identify the shared features in a phospholipid. This then allows the differences to be introduced, such as the presence of a phosphate group in place of the third fatty acid. Moving forwards, the students will learn that the two fatty acid tails are hydrophobic whilst the phosphate head is hydrophilic which leads into a key discussion point where the class has to consider how it is possible for the phospholipids to be arranged when both the inside and outside of a cell is an aqueous solution. The outcome of the discussion is the introduction of the bilayer which is critical for the lessons in topic 4 on the fluid mosaic model. The final part of the lesson explains how both facilitated diffusion and active transport mean that proteins are found floating in the cell membrane and this also helps to briefly prepare the students for upcoming topic 4 lessons.

This clear and detailed lesson describes how ATP is formed by chemiosmosis during the process of oxidative phosphorylation. The PowerPoint has been designed to cover all of the specification points under point 5.4 of the Edexcel A-level Biology B specification and includes details of the electron transport chain, proton gradients and ATP synthase including the roles of the electron carriers, the mitochondrial membranes and oxygen. 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 detailed steps and at each point, key facts are discussed and explored in further detail to enable a deep understanding to be developed. Students will see how the proton gradient across the inner membrane 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 by oxidative phosphorylation. Understanding checks are included throughout the lesson to enable the students to assess their progress and prior knowledge checks allow them to recognise the clear links to other topics and modules. This lesson has been written to tie in with the other uploaded lessons on the previous stages of aerobic respiration - glycolysis, the Link reaction and the Krebs cycle.

This fully-resourced lesson challenges students to identify environmental factors that limit the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover the fourth part of point 5.1 of the AQA A-level Biology specification and focuses on light intensity, carbon dioxide concentration and temperature. The lesson has been specifically written to tie in with the three previous lessons in this topic 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.

This fully-resourced lesson describes how carbon dioxide, light intensity and temperature limit the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover point 5.7 (viii) of the Edexcel A-level Biology B specification The lesson has been specifically written to tie in with the four previous lessons in this topic which covered the structure of the chloroplast, the light-dependent and light-independent stages and GALP as a raw material. 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, GALP 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

This fully-resourced lesson describes how GALP is used as a raw material in the production of monosaccharides, amino acids and other molecules. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.7 (vii) of the Edexcel A-level Biology B specification concerning the uses of GALP but as the lesson makes continual references to biological molecules, it can act as a revision tool for a lot of the content of topic 1. The previous lesson covered the light-independent stage and this lesson builds on that understanding to demonstrate how the product of the Calvin cycle, glyceraldehyde phosphate, is used. The start of the lesson challenges the students to identify two errors in a diagram of the cycle so that they can recall that most of the GALP molecules are used in the regeneration of ribulose bisphosphate. A quiz version of Pointless runs throughout the lesson and this is used to challenge the students to recall a biological molecule from its description. Once each molecule has been revealed, time is taken to go through the details of the formation and synthesis of this molecule from GALP or from GP in the case of fatty and amino acids. The following molecules are considered in detail during this lesson: glucose (and fructose and galactose) sucrose starch and cellulose glycerol and fatty acids amino acids nucleic acids A range of activities are used to challenge their prior knowledge of these molecules and mark schemes are always displayed for the exam-style questions to allow the students to assess their understanding. As detailed above, this lesson has been specifically written to tie in with the earlier lessons in this module on the structure of the chloroplast and the light-dependent and light-independent stages of photosynthesis.

This engaging lesson describes the basic structure of an amino acid and introduces them as the monomers of polypeptides. The PowerPoint has been designed to cover point 2.6 (i) of the Edexcel International A-level Biology specification and has been specifically written to lead into the next lesson on dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide as covered later in the topic. Moving forwards, the students are given time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference, before cysteine is considered in greater detail due to the presence of sulfur atoms. Students are briefly introduced to disulfide bridges so they will recognise how particular bonds form between the R groups in the tertiary structure which is covered in the next lesson. The lesson concludes with one more quiz round called LINK TO THE FUTURE where the students will see the roles played by amino acids in the later part of the course such as translation and dipeptides.

This fully-resourced lesson describes the inheritance of genes with loci on the X chromosomes and considers biological examples. The detailed PowerPoint and accompanying resources have been designed to cover point 2.15 (ii) of the Edexcel International A-level specification and focuses on the inheritance of red-green colour blindness and haemophilia in humans Key genetic terminology is used throughout and the lesson begins with a check on their ability to identify the definition of homologous chromosomes. Students will recall that the sex chromosomes are not fully homologous and that the smaller Y chromosome lacks some of the genes that are found on the X. This leads into one of the numerous discussion points, where students are encouraged to consider whether females or males are more likely to suffer from sex-linked diseases. In terms of humans, the lesson focuses on haemophilia and red-green colour blindness and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final task of the lesson challenge the students to apply their knowledge to an exam question about chickens and how the rate of feather production in chicks can be used to determine gender. All of the tasks are differentiated so that students of differing abilities can access the work and all exam questions have fully-explained, visual mark schemes to allow them to assess their progress and address any misconceptions

This fully-resourced lesson uses step by step guides to walk students through the interpretation of genetic pedigree diagrams for monohybrid inheritance. The PowerPoint and accompanying resources have been designed to cover point 2.15 (ii) of the Edexcel International A-level Biology specification and includes the inheritance when there are more than two alleles at a gene locus as well as those that demonstrate codominance. In order to minimise the likelihood of errors and misconceptions, the guides that are included within the lesson will support the students with the following: Writing parent genotypes Working out the different gametes that are made following meiosis Interpreting Punnett crosses to work out phenotypic ratios Students can often find pedigree trees the most difficult to interpret and to explain so exemplar answers are used and the worksheets are differentiated so students can seek assistance if necessary.

This lesson describes how monosaccharides are joined together during condensation reactions to form maltose, sucrose and lactose. The PowerPoint and accompanying resource have been designed to cover the third part of point 1.2 & 1.4 of the Edexcel International A-level Biology specification but also make links to the previous lesson on monosaccharides when considering the different components of these three disaccharides. The first section of the lesson focuses on a prefix and a suffix so that the students can recognise that the names of the common disaccharides end in -ose. In line with this, a quick quiz round is used to introduce maltose, sucrose and lactose before students are challenged on their prior knowledge as they have to describe how condensation reactions and the formation of glycosidic bonds were involved in the synthesis of each one. The main task of the lesson again challenges the students to recall details of a previous lesson as they have to identify the monomers of each disaccharide when presented with the displayed formula. Time is taken to show how their knowledge of these simple sugars will be important in later topics such as digestion, translocation in the phloem and the Lac Operon in the control of gene expression. The lesson finishes with two exam-style questions where students have to demonstrate and apply their newly acquired knowledge and the mark schemes are included within the lesson PowerPoint so students can assess their understanding and address any misconceptions if they have arisen.

This fully-resourced lesson describes the relationship between the structure of monosaccharides and their roles in living organisms. The engaging PowerPoint and accompanying resources have been designed to cover the second part of points 1.2 & 1.4 of the Edexcel International A-level Biology specification and describes alpha-glucose, galactose, fructose, deoxyribose and ribose. The lesson begins by reminding students that monosaccharides are the simplest sugars and that these monomers provide energy. Using the molecular formula of glucose as a guide, students will be given the general formula for the monosaccharides and will learn that deoxyribose is an exception to the rule that the number of carbon and oxygen atoms are equal. Moving forwards, students have to study the displayed formula of glucose for two minutes without being able to note anything down before they are challenged to recreate what they saw in a test of their observational skills. At this point of the lesson, the idea of numbering the carbons is introduced so that the different glycosidic bonds can be understood in an upcoming lesson as well as the recognition of the different isomers of glucose. The difference between alpha and beta-glucose is provided but students do not need to consider the beta form until topic 4. The remainder of the lesson focuses on the roles of the monosaccharides and the final task involves a series of application questions where the students are challenged to suggest why ribose could be considered important for active transport and muscle contraction

This lesson describes the differences between monosaccharides, disaccharides and polysaccharides, including glycogen and starch. The PowerPoint and accompanying resource have been designed to cover point 1.2 (i) of the Edexcel International A-level Biology specification and the main aim of the lesson is to prepare the students for the upcoming lessons on the individual carbohydrate groups. The lesson begins with a made-up round of the quiz show POINTLESS, where students have to try to identify four answers to do with carbohydrates. In doing so, they will learn or recall that these molecules are made from carbon, hydrogen and oxygen, that they are a source of energy which can sometimes be rightly or wrongly associated with obesity and that the names of the three main groups is derived from the Greek word sakkharon. A number of quick quiz rounds have been written into the lesson to introduce key terms in a fun and memorable way and the first round allows the students to meet some of common monosaccharides. Moving forwards, students will learn that a disaccharide is formed when two of these monomers are joined together and they are then challenged on their knowledge of condensation reactions which were originally encountered during the lesson on water. Students will understand how multiple reactions and multiple glycosidic bonds will result in the formation of a polysaccharide and glycogen and starch are introduced as well as amylose and amylopectin as components of this latter polymer.

This fully-resourced lesson explores how the structure of capillaries, arteries and veins relate to their functions. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 1.7 of the Edexcel International A-level Biology specification. This lesson has been written to build on any prior knowledge from iGCSE or earlier in this topic to enable students to fully understand each type of blood vessel has its particular features. Students will be able to make the connection between the narrow lumen and elastic tissue in the walls of arteries and the need to maintain the high pressure of the blood. A quick version of GUESS WHO is used to introduce smooth muscle and collagen as the substances that are found in the tunica media and externa and again the reason for their presence is explored and explained. The next part of the lesson looks at the role of the capillaries in exchange and links are made to diffusion to ensure that students can explain how the red blood cells pressing against the endothelium results in a short diffusion distance. The remainder of the lesson considers the structure of the veins and students are challenged to explain how the differences to those observed in arteries is due to the lower blood pressure found in these vessels. Valves are introduced and important mechanisms like the skeletal muscle pump are discussed to ensure that students can understand how the return of blood to the right atrium of the heart is maintained.

This lesson describes the role of haemoglobin in transport and explains the change in the dissociation curve when there is an increased concentration of carbon dioxide (the Bohr effect). The detailed PowerPoint and accompanying resources have been designed to cover points 1.9 (i) & (ii) of the Edexcel International A-level Biology specification and this lesson also compares the oxyhaemoglobin dissociation curve of foetal haemoglobin against maternal haemoglobin. The lesson begins with a version of the quiz show Pointless and this introduces haemotology as the study of the blood conditions. Students are told that haemoglobin has a quaternary structure as it is formed of 4 polypeptide chains which each contain a haem group with an iron ion attached and that it is this group which has a high affinity for oxygen. Time is taken to discuss how this protein must be able to load (and unload) oxygen as well as transport the molecules to the respiring tissues. Students will plot the oxyhaemoglobin dissociation curve and the S-shaped curve is used to encourage discussions about the ease with which haemoglobin loads each molecule. At this point, foetal haemoglobin and its differing affinity of oxygen is introduced and students are challenged to predict whether this affinity will be higher or lower than adult haemoglobin and to represent this on their dissociation curve. Moving forwards, the different ways that carbon dioxide is transported around the body involving haemoglobin are described and the dissociation of carbonic acid into hydrogen ions is discussed so that students can understand how this will affect the affinity of haemoglobin for oxygen in the final part of the lesson on the Bohr effect. A quick quiz is used to introduce Christian Bohr and the students are given some initial details of his described effect. This leads into a series of discussions where the outcome is the understanding that an increased concentration of carbon dioxide decreases the affinity of haemoglobin for oxygen. The students will learn that this reduction in affinity is a result of a decrease in the pH of the cell cytoplasm which alters the tertiary structure of the haemoglobin. The lesson finishes with a series of questions where the understanding and application skills are tested as students have to explain the benefit of the Bohr effect for an exercising individual.

This detailed lesson describes the relationship between the structure and function of starch and cellulose. The engaging PowerPoint and accompanying resource have been designed to cover point 4.9 of the Pearson Edexcel A-level Biology A specification and focuses on the importance of the glycosidic and hydrogen bonds for the structure of these polysaccharides. The structure of amylose and amylopectin was described during a lesson in topic 1, so the start of this lesson challenges the students on their recall of these details. They have to complete a comparison table for these two polysaccharides by identifying the monomer and type of glycosidic bonds that are found in each of the structures. Time is taken to explain how the greater resistance to digestion of amylose means that this carbohydrate is important for plant energy storage whereas the multiple chain ends in the branched amylopectin means that this polysaccharide can be hydrolysed quickly when energy is needed. The rest of the lesson describes the structure of cellulose and focuses on the link between the structure and the need for this polysaccharide to support the plant cell as well as the whole plant. Students will see how every other beta glucose monomer is rotated by 180 degrees and will learn that hydrogen bonds form between these molecules on the same chain as well as between adjacent chains in a cellulose microfibril. The lesson concludes with a quick quiz competition where the students have to compete to open a safe using a combination made up of key values associated with glycogen, starch and cellulose.

This fully-resourced lesson explains the meaning of biodiversity and describes how it can be calculated within a habitat and within a species. The engaging PowerPoint and accompanying resources have been designed to cover point 4.2 of the Pearson Edexcel A-level Biology A specification and in addition to biodiversity, 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.