This detailed and engaging lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. Both the PowerPoint and accompanying resources have been designed to cover the third part of point 8.4.1 of the AQA A-level Biology specification and ties in with the previous two lessons in this sub-topic on producing DNA fragments and the polymerase chain reaction. The lesson begins with the introduction of the terms transgenic and transformed. Students will learn that bacterial cells are the most commonly transformed cells so the next task challenges their recall of the structures of these cells so that plasmid DNA can be examined from that point onwards. A quick quiz competition is used to introduce the key term, vector, and then the rest of the lesson looks at the details of the five steps involved in the transformation of the host cell: Remove and prepare the plasmid to act as a vector Insert the DNA fragment into the vector Transfer the recombinant plasmid into the host cell Identify the cells which have taken up the recombinant plasmid All the transformed host cells to replicate and express the novel gene Time is taken to explore the finer details of each step such as the addition of the promoter and terminator regions, use of the same restriction enzyme to cut the plasmid as was used to cut the gene and the different types of marker genes. Links are continuously made to the previous lessons in this topic so that students feel confident to answer assessment questions which bring in knowledge from all of the sections.

Disaccharides are formed from the condensation of two monosaccharides and this lesson describes the formation of maltose, sucrose and lactose. The PowerPoint and accompanying question sheet have been designed to cover the second part of point 1.2 of the AQA 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

Monosaccharides are the monomers from which larger carbohydrates are formed and this lesson describes their structure and roles in living organisms. The detailed and engaging PowerPoint and accompanying resources have been designed to cover the first part of point 1.2 of the AQA A-level Biology specification and looks at alpha-glucose, beta-glucose, galactose, fructose, deoxyribose and ribose. 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. 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 and students are again challenged to draw a molecule of glucose, this time for the beta form. The remainder of the lesson focuses on the roles of the 6 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 fully-resourced lesson describes how triglycerides are formed during condensation reactions and compares saturated and unsaturated lipids. The engaging PowerPoint and accompanying worksheets have been designed to cover the points 1.14 (i) & (ii) of the Pearson Edexcel A-level Biology A specification and links are also made to related future topics such as the importance of the myelin sheath for the conduction of an electrical impulse. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from topics 1.12 & 1.13 so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

This detailed lesson describes the formation of polypeptides as well as the different levels of protein structures and links this to function. Both the engaging PowerPoint and accompanying resources have been designed to cover points 2.9 (ii) & (iii) of the Pearson Edexcel A-level Biology A specification but also makes specific reference to genes and therefore covers the details of point 2.8 too. 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. The lesson concludes with one final task where the students have to identify three errors in a passage about the hydrolysis of a dipeptide or polypeptide.

This fully-resourced lesson describes the movement of molecules by active transport, endocytosis and exocytosis and explains the need for ATP. The PowerPoint and accompanying worksheets have been designed to cover the second part of point 2.4 of the Pearson Edexcel A-level Biology specification. The first part of 2.4, concerning simple and facilitated diffusion, was covered in the previous lesson. The start of the lesson challenges the students to use their prior knowledge of biological molecules to come up with the abbreviation ATP and they will learn that this is a phosphorylated nucleotide that contains adenine, ribose and three phosphate groups. Students may not have known this as the energy currency from GCSE so time is taken to explain that this molecule must be broken down to release energy and students are challenged to recall which type of reaction will be involved and to predict the products of such a reaction. This hydrolysis of ATP can be coupled to energy-requiring reactions within the cell and the rest of the lesson focuses on the use of this energy for active transport, endocytosis and exocytosis. Students are challenged to answer a series of questions which compare active transport against the forms of passive transport and to use data from a bar chart to support this form of transport. In answering these questions they will discover that carrier proteins are specific to certain molecules and time is taken to look at the exact mechanism of these transmembrane proteins. A quick quiz round introduces endocytosis and the students will see how vesicles are involved along with the enery source of ATP to move large substances in or out of the cell. The lesson concludes with a link to a future topic as the students are shown how exocytosis is involved in a synapse.

This concise lesson describes the basic structure of an amino acid and introduces them as the monomers of polypeptides. The engaging PowerPoint has been designed to cover point 2.9 (i) of the Pearson Edexcel A-level Biology A 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 detailed in specification point 2.8. Moving forwards, the 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, 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 lesson describes the relationship between the structure and function of the vacuole, chloroplast and cell wall, as found in plant cells. Additional structures, such as the nucleus and mitochondria, were covered in the previous lesson on the structure of eukaryotic animal cells and the detailed content of these two lessons has been designed in parallel to cover the main content of point 2.1.1 of the AQA A-level Biology specification. The lesson begins with a task called REVERSE GUESS WHO which will challenge the students to recognise a cell structure from a description of its function. This will remind students that plant cells are eukaryotic and therefore contain a cell-surface membrane, a nucleus (+ nucleolus), a mitochondria, a Golgi apparatus, ribosomes and rough and smooth endoplasmic reticulum like the animal cells. Moving forwards, the rest of the lesson focuses on the relationship between the structure and function of the vacuole, chloroplast and cellulose cell wall. When considering the vacuole, key structures such as the tonoplast are described as well as critical functions including the maintenance of turgor pressure. A detailed knowledge of the structure of the chloroplast at this early stage of their A-level studies will increase the likelihood of a clear understanding of photosynthesis when covered in topic 5. For this reason, time is taken to consider the light-dependent and light-independent reactions and to explain how these stages are linked. The final part of the lesson challenges the students on their knowledge of cellulose as a polysaccharide as previously covered in topic 1. In addition to the focus on plant cells, the presence of chloroplasts and a cell wall in algae and the latter in fungi is also described. The previous lesson which contains the content that ties in closely with this one has been uploaded under the title “Structure of eukaryotic (animal) cells”

This fully-resourced lesson describes the modes of action of the T and B lymphocytes in the immune response. The detailed PowerPoint and accompanying resources have been designed to cover point 2.4 of the CIE A-level Biology specification and the structure of antibodies and the roles of memory cells is also briefly introduced. Antigen presentation was introduced at the end of the previous lesson so the task at the start of this lesson challenges students to recognise the name of this process and then they have to spot the errors in the passage that describes the details of this event. This reminds them that contact between the APC and T lymphocytes is necessary to elicit a response which they will come to recognise as the cellular response. A series of quick quiz rounds reveals key terms in a memorable way and one that is introduced is helper T cells. Time is then taken to describe the importance of cell signalling for an effective response and students will learn how the release of chemicals by these cells activates other aspects of the response. The role of the killer T cells is also described before an exam-style question is used to check on their understanding at this point of the lesson. This leads into the section of the lesson that deals with the humoral response and students will understand how this involves the antibodies that are produced by the plasma cells that are the result of clonal selection and expansion. The remainder of the lesson focuses on the role of the antibodies and the attachment of phagocytes to opsonins.

This lesson describes and explains the processes of simple diffusion and facilitated diffusion. The PowerPoint and accompanying resources have been designed to cover the first part of specification point 4.2 (a) of the CIE International A-level Biology course and the factors that increase the rate of diffusion are covered along with the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins. The structure and properties of cell membranes was covered in topic 4.1 so this lesson has been written to include continual references to the content of that lesson. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane

Adenosine triphosphate is the universal energy currency and this lesson focuses on the role of this molecule in cell. The PowerPoint has been designed to cover point1.2 © of the CIE International A-level Biology specification and also explains how ATP must be hydrolysed to release energy and then re-synthesised during respiration and photosynthesis in the mitochondria and chloroplast respectively. As students were introduced to the structure of DNA and RNA at GCSE, the start of this lesson challenges them on their knowledge of these polynucleotides so that they can recognise that ATP consists of adenine, ribose and three phosphate groups. In order to release the stored energy, ATP must be broken down and students will be given time to discuss which reaction will be involved as well as the products of this reaction. Time is taken to describe how the hydrolysis of ATP can be coupled to energy-requiring reactions within cells and the examples of active transport and skeletal muscle contraction are used as these are covered in greater detail in topics 4 and 15. The final part of the lesson considers how ATP must be re-synthesised and students will learn that this occurs in the mitochondria and chloroplast during aerobic respiration and photosynthesis respectively.

This detailed lesson describes the fluid mosaic model of membrane structure and outlines the roles of the different components . Fully resourced, the PowerPoint and accompanying worksheets have been designed to cover specification point 4.1 (a) of the CIE International A-level Biology specification but as the membranes and target cells are discussed, points 4.1 (b) and © are also partially covered The fluid mosaic model is introduced at the start of the lesson so that it can be referenced at appropriate points throughout the lesson. Students were introduced to phospholipids in topic 2 and so an initial task challenges them to spot the errors in a passage describing the structure and properties of this molecule. This reminds them of the bilayer arrangement, with the hydrophilic phosphate heads protruding outwards into the aqueous solutions on the inside and the outside of the cell. In a link to some upcoming lessons on the transport mechanisms, the students will learn that only small, non-polar molecules can move by simple diffusion and that this is through the tails of the bilayer. This introduces the need for transmembrane proteins to allow large or polar molecules to move into the cell by facilitated diffusion and active transport. Proteins that act as receptors as also introduced and an opportunity is taken to make a link to an upcoming topic so that students can understand how hormones or drugs will bind to target cells in this way. Moving forwards, the structure of cholesterol is covered and students will learn that this hydrophobic molecule sits in the middle of the tails and therefore acts to regulate membrane fluidity. The final part of the lesson challenges the students to apply their newly-acquired knowledge to a series of questions where they have to explain why proteins may have moved when two cells are used and to suggest why there is a larger proportion of these proteins in the inner mitochondrial membrane than the outer membrane.

This fully-resourced lesson has been written to support students to develop a clear understanding of 16 key genetic terms, including the 8 that are detailed in specification point 8.2 (i) of the Edexcel A-level Biology B specification. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and to act as an understanding check.

This lesson describes the role of reduced NAD and FAD as sources of electrons and protons for the electron transport system. The PowerPoint has been designed to cover the content of topic 3 point (d) of A2 unit 3 as set out in the WJEC A-level biology specification and explains how ATP is produced by oxidative phosphorylation. The lesson begins with a recognition that the start of this stage doesn’t have a carbon-based molecule as was observed with the Krebs cycle. This leads into a discussion period, where the students are challenged to study their notes on glycolysis and the Krebs cycle to suggest which products of these reactions could initiate this stage. This introduces the reduced coenzymes as the sources of electrons and protons for the electron transport system, and as shown in the cover image, a step-by-step guide walks the students through the key parts of this stage. Students will learn about the creation of a proton gradient across the inner mitochondrial membrane and the formation of ATP and water when oxygen acts as the final electron acceptor. This lesson is a follow-on lesson from the previous lessons covering the Krebs cycle, glycolysis and the need for respiration.

This lesson describes the meaning of absorption and action spectra and explains why plants contain several photosynthetic pigments. The PowerPoint and accompanying resources have been designed to cover both specification points in topic 5.6 of the Edexcel A-level biology B specification and includes key information to prepare the students for the photosynthesis lessons in topic 5.7. The students are presented with a picture of a leaf with chlorosis at the start of the lesson and are challenged to explain the appearance and name the ion which is deficient in the soil, drawing on their knowledge from topic 1. The lesson has been intricately planned to build on their limited knowledge of photosynthesis from GCSE, and to introduce key details such as the location of chlorophyll in the photosystems in the thylakoids. The students will learn that there are two forms of chlorophyll a, as well as a chlorophyll b, and a quick quiz round is used to reveal the values of 680 and 700. The absorption spectrum for chlorophyll a and b are displayed and when the students are presented with a spectra, they will discover that there are more chloroplast pigments. The carotenoids are introduced and the students have to interpret the spectra to reveal more details about these pigments. The meaning of an action spectrum is provided and the students are challenged to draw a sketch graph to show how the rate of photosynthesis differs for different wavelengths, before the correlation between the two spectra is considered.