Cellular Transport – 1.15

Animal Exchange and Transport – (1BI0): Higher Tier

In this course, Dr Matt Ivory (Cardiff University) takes us through animal exchange and transport, including topics 1.15-1.17 & 8.1-8.11 in the Pearson Edexcel GCSE Biology (9-1) Higher Specification. We start (i) by covering the fundamentals of how substances are transported in and out of cells, including diffusion, osmosis and active transport (Topic 1.15); we then (ii) apply the principle of osmosis to a practical experiment to measure percentage gain and loss of mass in potatoes (Topics 1.16, 1.17); following this (iii) we describe the need to transport various substances such as oxygen and water, whilst also highlighting the need for exchange surfaces in order to transport said substances (Topics 8.1, 8.2); we then (iv) take a closer look at diffusion and various factors which can affect its action, as well as introducing Fick's Law (Topics 8.4B, 8.5B); then we begin to look at specific exchange surfaces, beginning with (v) the lungs and their adaptations for gas exchange (Topic 8.3); we next (vi) look at the blood and its components (Topic 8.6); following this (vii) is the blood vessels and how their structure is related to their function (Topic 8.7, 8.8); we move on (viii) to our final organ system, the heart, breaking down its structure as well as describing how to calculate cardiac output (Topics 8.8, 8.12); our focus then (ix) shifts to respiration, defining it as well as describing both the anaerobic and aerobic forms of respiration (Topics 8.9, 8.10); and finally (x) we finish up with an experiment on how to measure the rate of respiration in living organisms (Topic 8.11).

Cellular Transport – 1.15

In the first mini-lecture, we introduce the key concepts behind how substances are transported in and out of cells. We begin with highlighting the need for concentration gradients and diffusion. We then move on to discuss osmosis and how solute concentrations can influence the movement of water in and out of cells and how this may differ in animal and plant cells. We round of this mini-lecture by discussing active transport and the concept of how to move substances against a concentration gradient.