Organisms Respond to Changes in their Environments (A Level only), 6.1.9 Investigating Touch and Temperature Receptors, 6.1.12 Investigating Variables that Affect Heart Rate, 6.2.6 Maths Skill: Calculating Maximum Impulse Frequency, 6.2.8 Transmission Across a Cholinergic Synapse, 6.3.3 Examining Skeletal Muscle Under a Microscope, 6.4.6 Control of Blood Glucose Concentration, 6.4.8 Calculating the Concentration of Glucose in Urine, 7. This is because there is a greater area that needs to receive the substance being diffused, but less area for that substance to actually enter the cell. Question. (the later videos in the playlist are Grade 7 - 9 level). this is actually why cells divide. You could consider the cell to be a sphere and them just calculate it, if you know the radius caluculate it like this Remember that diffusion is a passive process, so when it occurs in a living organism the cells of that organism do not provide the particles involved with energy to diffuse. Something went wrong, please try again later. IBO was not involved in the production of, and does not endorse, the resources created by Save My Exams. By infusing cubes of agar with a pH indicator, and then soaking the treated cubes in vinegar, you can model how diffusion occurs in cells. Divide the surface area by the volume. Figure 4.4. Make sure students are comfortable with expressing quantities as ratios first e.g. The calculations are done Volume of a sphere calculator with surface area to volume ratio The surface area to volume ratio is an important feature in catalysis and surface chemistry The higher the ratio then the more surface area is available for reaction, hence the better the catalyst This diagram shows the surface area to volume ratio of three different sizes cubes Grade 5. Good practice calculations for lower ability classes. 1.2 What Happens in Cells (& What do Cells Need? The control sets the volume and scale of the plot on the right. 1.1.10 Biochemical Tests: Sugars & Starch, 1.1.11 Finding the Concentration of Glucose, 1.3.7 The Molecular Structure of Haemoglobin, 1.3.8 The Molecular Structure of Collagen, 1.4.4 Required Practical: Measuring Enzyme Activity, 1.4.5 Maths Skill: Drawing a Graph for Enzyme Rate Experiments, 1.4.6 Maths Skill: Using a Tangent to Find Initial Rate of Reaction, 1.4.7 Limiting Factors Affecting Enzymes: Temperature, 1.4.8 Limiting Factors Affecting Enzymes: pH, 1.4.10 Limiting Factors Affecting Enzymes: Enzyme Concentration, 1.4.11 Limiting Factors Affecting Enzymes: Substrate Concentration, 1.4.12 Limiting Factors Affecting Enzymes: Inhibitors, 1.4.13 Models & Functions of Enzyme Action, 1.4.14 Practical Skill: Controlling Variables & Calculating Uncertainty, 1.5 Nucleic Acids: Structure & DNA Replication, 1.5.2 Nucleotide Structure & the Phosphodiester Bond, 1.5.6 The Origins of Research on the Genetic Code, 1.5.8 The Process of Semi-Conservative Replication, 1.5.9 Calculating the Frequency of Nucleotide Bases, 2.2.2 Microscopy & Drawing Scientific Diagrams, 2.2.6 Cell Fractionation & Ultracentrifugation, 2.2.7 Scientific Research into Cell Organelles, 2.3 Cell Division in Eukaryotic & Prokaryotic Cells, 2.3.7 Uncontrolled Cell Division & Cancer, 2.4.2 Components of Cell Surface Membranes, 2.4.8 Comparing Osmosis in Animal & Plant Cells, 2.4.13 Factors Affecting Membrane Fluidity, 2.5.5 The Role of Antigen-Presenting Cells, 2.6 Vaccines, Disease & Monoclonal Antibodies, 2.6.6 Ethical Issues with Vaccines & Monoclonal Antibodies, 3.1.5 Adaptations of Gas Exchange Surfaces, 3.2.3 Looking at the Gas Exchange under the Microscope, 3.2.11 Correlations & Causal Relationships - The Lungs, 3.4.7 Animal Adaptations For Their Environment, 3.5.8 Interpreting Data on the Cardiovascular System, 3.5.9 Correlations & Causal Relationships - The Heart, 3.5.10 Required Practical: Dissecting Mass Transport Systems, 4.2.6 Nucleic Acid & Amino Acid Sequence Comparison, 4.3 Genetic Diversity: Mutations & Meiosis, 4.3.5 Meiosis: Sources of Genetic Variation, 4.3.7 The Outcomes & Processes of Mitosis & Meiosis, 4.4.2 Maths Skill: Using Logarithms When Investigating Bacteria, 4.4.4 Directional & Stabilising Selection, 4.6.7 Quantitative Investigations of Variation, 4.6.9 Genetic Relationships Between Organisms, 5. How is the surface area to volume ratio found? Tocalculatethis ratio involves some simple maths, but itsworth practising this with students and clarifying units for area and volume. // Marlyne Barrett Natural Hair, Helena Felony Arrests, Nrj Mugshots Busted Newspaper, Does Lakeith Stanfield Speak Japanese In Yasuke, What Is Pulmonary Disease Pattern On Ecg, Articles S