Exam Board: Cambridge International Course: AS Biology Unit: Biomolecules Lesson: Testing for Biomolecules File format: PowerPoint Sylabbus code: 2.1 The lesson covered various tests used for detecting specific molecules. The Benedict’s test is used to identify reducing sugars. It gives a positive result when reducing sugars, such as glucose, forming a colored precipitate. For non-reducing sugars, such as sucrose, hydrolysing the glycosidic bond is required before carrying out the Benedict’s test. The Iodine test is used to detect the presence of starch. A positive result is indicated by a color change from brown to blue-black. The Biuret test is utilised to test for the presence of proteins and a positive result is shown by a color change from blue to violet or pink. Finally, the emulsion test is used to detect lipids (fats and oils) in a substance and a positive result creates a cloudy emulsion. There is a final quiz with answers for the teacher in the comment box below the slide.

Exam Board: Cambridge International Course: AS Biology Unit: Biomolecules Lesson: Lipids File format: PowerPoint Sylabbus code: 2.2 Lipids function as a concentrated energy source, provide insulation and organ protection, and aid in buoyancy control for marine organisms. They contribute to cell membrane structure, vitamin absorption, and hormone synthesis. Fats and oils enhance food flavor, texture, and satiety. Saturated fatty acids are solid at room temperature with straight chains, while unsaturated fatty acids are liquid with double bonds. The emulsion test, using ethanol, detects lipids in substances. Ester bonds form through alcohol and carboxylic acid esterification, and they can be hydrolysed by water. There is a final quiz with answers for the teacher in the comment box below the slide.

Exam Board: Cambridge International Course: AS Biology Unit: Biomolecules Lesson: Proteins File format: PowerPoint Sylabbus code: 2.3 This lesson explores proteins which are essential biomolecules with diverse functions, consisting of amino acids linked by peptide bonds. Their complex three-dimensional structures dictate their specific roles. The primary structure represents the linear sequence of amino acids. Secondary structure involves local folding patterns like alpha helices and beta sheets. Tertiary structure refers to the overall three-dimensional arrangement of the protein. Some proteins possess quaternary structures formed by the association of multiple subunits, while others do not. Genetic mutations can affect protein structure and function. Proteins can be broadly categorized into two structural forms: globular and fibrous. The biuret test, which triggers a color change, is commonly used to detect the presence of proteins or peptides. The slides include an end of lesson quiz. The answers are in the comment box below the slide.

Exam Board: Cambridge International Course: AS Biology Unit: Biomolecules Lesson: Carbohydrates File format: PowerPoint Sylabbus code: 2.2 In this lesson, we covered various aspects of carbohydrates. We discussed the properties of glucose, a monosaccharide, as well as disaccharides like sucrose and lactose. Polysaccharides such as starch, glycogen, cellulose, and chitin were also explored. We examined the formation and breaking of glycosidic bonds that connect sugar units in carbohydrates. Additionally, we learned about biochemical tests to distinguish between reducing and non-reducing sugars, providing a valuable tool for carbohydrate analysis. There is a final quiz with answers for the teacher in the comment box below the slide.

AS Biology - Gas Exchange and Lung Structure. Powerpoint with images and final quiz. For the Cambridge International Specification but can be applied to all exam boards. Includes Gas Exchange, Lung Structure and Alveoli structure.

AS Biology - Powerpoint with quizzes on nucleotide structure, DNA structure and DNA replication. For the Cambridge International Exam Board, but can be adapted to any UK board.

IGCSE / GCSE Biology Homeostasis slide show for the Cambridge International sylabbus (although it can be adapted). It includes an exam style activity and final ‘true or false’ quiz.

Simple lesson of Earth’s structure with a starter and worksheet. For Key Stage 3.

A Level Biology - Pacinian corpuscle Information on the Pacinian Corpuscle and then 4 problem questions for students to complete. For AQA, but can be used for any sylabbus.

Lesson slides on the Earth’s layers, and Tectonic plates. Includes starter questions and a final quiz. There’s also an exercise on labelling the Earth’s layers, a mix and match, and a final quiz. For KeyStage 3, or ages 11-14, approximately.

Exam Board: Cambridge International Course: AS Biology Unit: Biomolecules Lesson: Water File format: PowerPoint Sylabbus code: 2.4 This lesson explores the properties of water and their significance for living organisms. It covers the latent heat of vaporization, specific heat capacity, cohesion and adhesion, and the density anomaly. These properties play crucial roles in regulating temperature, facilitating transport, and supporting life in various environments. The slides include an end of lesson quiz. The answers are in the comment box below the slide.

Cambridge International - AS Level Biology Resource Type: Revision Guide Format: Word Unit: Biomolecules Topic: Water Summary: Hydrogen bonding occurs between water molecules due to the polarity of the water molecule. A water molecule consists of two hydrogen atoms bonded to one oxygen atom. The oxygen atom has a slightly negative charge, while the hydrogen atoms have a slightly positive charge. This polarity allows water molecules to form hydrogen bonds with each other. The oxygen atom of one water molecule attracts the hydrogen atom of another water molecule, creating a weak bond. This attraction between water molecules leads to the unique properties of water. Water’s solvent action is crucial for living organisms. Its polar nature allows it to dissolve a wide range of substances, such as salts, sugars, and many organic molecules. This property enables water to transport essential nutrients, ions, and waste products within organisms. Water has a high specific heat capacity, meaning it can absorb and retain a large amount of heat without a significant change in temperature. This property helps regulate temperature in living organisms, preventing sudden fluctuations. It buffers against temperature changes in environments, providing a stable habitat for many organisms. Water also possesses a high latent heat of vaporization, requiring a significant amount of heat to convert it from a liquid to a gas. This property allows organisms to cool down by evaporative cooling, such as through sweating or panting. It helps maintain temperature homeostasis and prevents overheating in organisms. Understanding these properties of water provides insights into its vital roles as a solvent, temperature regulator, and coolant in the functioning and survival of living organisms.