A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
This fully-resourced lesson describes the key steps in the process of DNA replication, including the role of DNA polymerase. Both the detailed PowerPoint and accompanying resources have been designed to cover point 2.11 (i) of the Pearson Edexcel A-level Biology A specification and this lesson also explains why this replication is known as semi-conservative in order to prepare the students for the following lesson on Meselson and Stahl’s experiment.
The main focus of this lesson is the role of DNA polymerase in the formation of the growing nucleotide strands but the students will also learn that the hydrogen bonds between nucleotide bases are broken by DNA helicase and that DNA ligase joins the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.
This detailed lesson uses haemoglobin and collagen as examples to describe the structure, properties and functions of globular and fibrous proteins. The engaging PowerPoint and accompanying worksheet have been designed to cover point 2.9 (iv) of the Pearson Edexcel A-level Biology A specification and focuses on the shape, solubility and function of these two types of protein.
The first part of the lesson looks at the structure of haemoglobin, and describes how the presence of an iron-containing haem group on the outside of the 4 polypeptide chains explains its ability to form oxyhaemoglobin. Moving forwards, the importance of the solubility of this protein is considered and related to the direction that the hydrophobic R groups point. At this point of the lesson, the students are challenged to construct a comparison table which can be filled in as the lesson progresses and as they are given more details of collagen. The section of the lesson concerning collagen begins with the introduction of its function in the artery wall so that students can recognise how fibrous proteins have roles associated with mechanical strength. Time is taken to discuss their solubility as well as the presence of repetitive amino acid sequences. The remainder of the lesson considers four more proteins and the final task challenges the students to use their completed table to write a summary passage comparing globular and fibrous proteins.
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 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 detailed lesson describes the process of translation and the roles of the mRNA, tRNA, rRNA and amino acids during this second stage of protein synthesis. Both the PowerPoint and accompanying resources have been designed to cover the second part of points 2.5 (i) & (ii) of the Pearson Edexcel A-level Biology A specification and contains constant links to the previous lessons in this topic on transcription and the structure of DNA and RNA.
Translation is a topic which is often poorly understood and so this lesson has been written to support the students in answering the different types of questions by knowing and including the details of the key structures involved. The lesson begins by challenging the students to consider why it is so important that the amino acids are assembled in the correct order during the formation of the chain. Moving forwards, a quick quiz round called “LOST IN TRANSLATION” is used to check on their prior knowledge of the mRNA strand, the tRNA molecules and the ribosomes. The next task involves a very detailed description of translation that has been divided into 14 statements which the students have to put into the correct order. By giving them a passage that consists of this considerable detail, they can pick out the important parts to use in the next task where they have to answer shorter questions worth between 3 and 4 marks. These types of questions are common in the assessments and by building up through the lesson, their confidence to answer this type should increase. The final two tasks of the lesson involve another quiz, where the teams compete to transcribe and translate in the quickest time before using all that they have absorbed to answer some questions which involve the genetic code and the mRNA codon table
This detailed lesson explains how the process of transcription results in the production of mRNA. Both the detailed PowerPoint and accompanying question worksheet have been designed to cover the first part of points 2.5 (i) & (ii) of the Pearson Edexcel A-level Biology A specification
The lesson begins by challenging the students to work out that most of the nuclear DNA in eukaryotes does not actually code for polypeptides. This allows the promoter region and terminator region to be introduced, along with the structural gene. Through the use of an engaging quiz competition, students will learn that the strand of DNA involved in transcription is known as the template (or anti-sense) strand and the other strand is the coding (or sense) strand. Links to previous lesson on the structure of DNA and RNA are made throughout and students are continuously challenged on their prior knowledge as well as their current understanding of the lesson topic. Moving forwards, the actual process of transcription is covered in a 7 step bullet point description where the students are asked to complete each passage using the information previously provided. An exam-style question is used to check on their understanding before the final task of the lesson looks at the journey of mRNA to the ribosome for the next stage of protein synthesis, translation.
This detailed and engaging lesson describes the basic structure of a mononucleotide and the similarities and differences between DNA and RNA. The PowerPoint and accompanying worksheet containing exam-style questions have been designed to cover points 2.5 (i) & (ii) of the Pearson Edexcel A-level Biology A specification.
In topic 1, the students were introduced to a number of monomers and the start of the lesson challenges them to recognise the key term nucleotide when only the letters U, C and T are shown. The next part of the lesson describes the structure of a DNA nucleotide and an RNA nucleotide so that the pentose sugar and the bases adenine, cytosine and guanine can be recognised as similarities whilst deoxyribose and ribose and thymine and uracil are seen as the differences. Time is taken to discuss how a phosphodiester bond is formed between adjacent nucleotides and their prior knowledge and understanding of condensation reactions is tested through a series of questions. Students are then introduced to the purine and pyrimidine bases and this leads into the description of the double-helical structure of DNA and the hydrogen bonds between complementary bases. The final section of the lesson describes the structure of mRNA, tRNA and rRNA and students are challenged to explain why this single stranded polynucleotide is shorter than DNA
In addition to the current understanding and prior knowledge checks, a number of quiz rounds have been written into the lesson to introduce key terms in a fun and memorable way and the final round acts as a final check on the structures of DNA and RNA.
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 detailed and fully-resourced lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer and membrane proteins. The PowerPoint and accompanying worksheets have been designed to cover point 2.2 of the Pearson Edexcel A-level Biology A specification and makes links to the fluid mosaic model which is covered in greater detail in the next lesson.
Students were introduced to triglycerides in topic 1 and the start of this lesson challenges them to recall the structure of this lipid to identify the shared features of a phospholipid. This introduces the structure of this macromolecule as a glycerol molecule, two fatty acids and a phosphate group. Time is taken to look at the differing properties of the phosphate group and the fatty acid tails so that students become comfortable with the terms hydrophobic and hydrophilic. At this point, the class is given an opportunity to discuss how the phospholipids are arranged when both the inside and outside of the cell contains an aqueous solution and the phospholipid bilayer as the fabric of the membrane is subsequently met. 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 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. It is at this point of the lesson that students will meet the fluid mosaic model and will begin to understand how this describes the dynamic nature of the membrane as well as explaining the interaction with the environment. 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 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 and fully-resourced lesson describes the relationship between the structure and function of glycogen and starch. The engaging PowerPoint and accompanying resources have been designed to cover the fourth part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification and clear links are also made to the previous lessons in this topic where the monosaccharides and disaccharides were introduced.
The lesson begins with the CARBOHYDRATE WALL where students have to use their prior knowledge to collect the 9 carbohydrates on show into 3 groups. This results in glycogen, starch and cellulose being grouped together as polysaccharides and the structure and roles of the first two are covered over the course of the lesson. Students will learn how key structural features like the 1 - 4 and 1 - 6 glycosidic bonds and the hydrogen bonds dictate whether the polysaccharide chain is branched or unbranched and also allows for spiralling. Following the description of the structure of glycogen, students are challenged to design an exam question in the form of a comparison table so that it can be completed as the lesson progresses and they learn more about starch. This includes a split in the starch section of the table so that the differing structures and properties of amylose and amylopectin can be considered. The importance of the compact structure for storage is discussed as well as the branched chains of amylopectin acting as quick source of energy when it is needed. The lesson concludes with a question and answer section that guides the students when answering a question about the importance of the lower solubility of the polysaccharides when compared to the monosaccharides.
Disaccharides are formed from the condensation of two monosaccharides and this lesson describes the formation of maltose, sucrose and lactose. The concise PowerPoint and accompanying question sheet have been designed to cover the third part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification but also continually 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 extracellular enzymes, translocation in the phloem and the control of gene expression as exemplified by the Lac Operon. The lesson finishes with two exam-style questions where students have to demonstrate and apply their newly acquired knowledge
This fully-resourced lesson describes the relationship between the structure of monosaccharides and their roles in living organisms. The detailed and engaging PowerPoint and accompanying resources have been designed to cover the second part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification and looks at alpha-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 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 engaging lesson acts as an introduction to carbohydrates and describes the differences between monosaccharides, disaccharides and polysaccharides. The PowerPoint and accompanying worksheet have been designed to cover the first part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification and make clear links to the upcoming lessons in this sub-topic on these three main groups of carbohydrates.
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. The final part of the lesson considers how hydrolysis reactions allow polysaccharides and disaccharides to be broken back down into monosaccharides.
Water is very important for living organisms because of its numerous properties and this lesson focuses on its role as a solvent in transport. The engaging and detailed PowerPoint and accompanying worksheet have been designed to cover point 1.2 of the Pearson Edexcel A-level Biology A specification and also explains the importance of the dipole nature for this role in transport.
A mathematical theme runs throughout the lesson as students have to match the numbers calculated in the starter task to water statistics, such as the percentage of the volume of blood plasma that is water. This has been included to try to increase the relevance of each property so that it can be described in a biological context. Time is taken at the beginning of the lesson to describe the structure of water in terms of the covalent bonds between the oxygen and hydrogen atoms as well as the hydrogen bonds which form between molecules because of its polarity. Students will understand how water is a solvent which means that it is critical for transport in animals, a topic covered in the next few lessons but also for transport in plants as discussed in topic 4. The high heat capacity and latent heat of vaporisation of water is also discussed and explained through the examples of thermoregulation and the maintenance of a stable environment for aquatic animals. The final part of the lesson focuses on the involvement of water in condensation and hydrolysis reactions, two reactions which must be well understood for topic 1 and 2 and the formation and breakage of polysaccharides, lipids, polypeptides and polynucleotides.
The biological molecules topic is incredibly important, not just because it is found at the start of the course, but also because of its detailed content which must be well understood to promote success with the other 7 AQA A-level Biology topics. Many hours of intricate planning has gone into the design of all of the 20 lessons that are included in this bundle to ensure that the content is covered in detail, understanding is constantly checked and misconceptions addressed and that engagement is high. This is achieved through the wide variety of tasks in the PowerPoints and accompanying worksheets which include exam-style questions with clear answers, discussion points, differentiated tasks and quick quiz competitions.
The following specification points are covered by the lessons within this bundle:
Monomers and polymers
Condensation and hydrolysis reactions
Common monosaccharides
Maltose, sucrose and lactose
The structure and functions of glycogen, starch and cellulose
Biochemical tests using Benedict’s solution for reducing sugars and non-reducing sugars and iodine/potassium iodide for starch
The structure and properties of triglycerides and phospholipids
The emulsion test for lipids
The structure of amino acids
The formation of dipeptides and polypeptides
The levels of protein structure
The biuret test for proteins
Enzymes act as biological catalysts
The induced-fit model of enzyme action
The properties of an enzyme
The effect of temperature on the rate of an enzyme-controlled reaction
The effect of enzyme and substrate concentration on the rate of an enzyme-controlled reaction
The effect of competitive and non-competitive inhibitors on the rate of an enzyme-controlled reaction
The structure of DNA and RNA
The semi-conservative replication of DNA
ATP as the universal energy currency
The properties of water and its importance in Biology
Inorganic ions
Due to the detail of each of these lessons, it is estimated that it will take in excess of 2 months of allocated teaching time to cover the content.
If you would like to see the quality of the lessons, download the monomers and polymers, polysaccharides, triglycerides, dipeptides and polypeptides and inorganic ions lessons as these have been shared for free
This detailed lesson describes the formation of dipeptides & polypeptides and the relationship between the structure and roles of proteins in living organisms. Both the engaging PowerPoint and accompanying resources have been designed to cover the second part of point 1.4.1 of the AQA A-level Biology specification.
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.
Amino acids are the monomers of polypeptides and this lesson describes their structure and makes links to related topics such as genes and dipeptides. The engaging PowerPoint has been designed to cover the first part of point 1.4.1 of the AQA A-level Biology specification 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, 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 mineral ions.
This detailed and engaging lesson describes how the roles of hydrogen, iron, sodium and phosphate ions are based on their properties. The PowerPoint and accompanying worksheet have been designed to cover point 1.8 of the AQA A-level Biology specification.
The lesson begins with a made-up round of POINTLESS where students have to use their prior knowledge of topic 1 to identify four biological molecules. All four of these molecules are connected by a phosphate group and this acts to remind students that phosphate ions are a component of both DNA and ATP. Moving forwards, the rest of the lesson explores the role of hydrogen ions in pH, iron in haemoglobin and sodium in the co-transport of glucose and amino acids. The lesson has been written so that links can be made to upcoming topics including the regulation of heart rate, transport of oxygen and selective reabsorption in the nephron of the kidney.
This fully-resourced lesson describes how the different properties of water make this biological molecule incredibly important in Biology. The engaging PowerPoint and accompanying worksheets have been designed to cover point 1.7 of the AQA A-level Biology specification.
Hydrolysis reactions have been a recurring theme throughout topic 1, 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. A quick quiz round is used to introduce cohesion and tension so students can understand how the column of water is able to move along this vascular tissue without interruption. 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.