Secondary Catalogue

Photosynthesis supplies all oxygen for life, and it began in the sea. Amazingly, it all relies on one basic kind of chemical reaction that was achieved over two billion years ago by cyanobacteria, and cyanobacteria living as endosymbionts in plants and phytoplankton still produce almost all our oxygen. This programme tells the story of the cyanobacteria, how they changed our planet and are involved in supporting its many life forms. We look at the four major groups that photosynthesise in the sea: cyanobacteria, eucaryote phytoplankton (microalgae), seaweeds (macroalgae), and seagrasses. These groups are responsible for supplying around half the oxygen we breathe—so in terms of understanding the processes that keep us alive, this is a very important story. Show Less

In the final episode, 'Heat and the Human Body', we look at the brilliant systems within our bodies that allow us to maintain a more-or-less constant body temperature regardless of the weather conditions. Sweating, shivering, pumping more blood to some parts of our bodies than to other parts, curling up into a ball, and spreading out your arms and legs all play their part in keeping our bodies at the right temperature! But what happens when we reach our limits? Show Less

Everyone likes to visit the beach. But for living things a beach represents one of the toughest environments on earth. Beaches are in constant flux, hammered by waves and wind and extremes of temperature, sometimes submerged and sometimes dry. Beach erosion threatens human activities too. This program looks at many aspects of beaches, from the life in the littoral zone to the basic geology of beaches. Show Less

While ecosystems face increasing pressure from human activity, science plays a critical role in controlling and minimising harmful effects. This clip explores the role of science and technology in identifying impacts on ecosystems and finding solutions for a more sustainable future. It provides students of biology and other sciences with an excellent overview of this important area of study. Show Less

Every organism lives in an ecosystem. This clip defines and looks at different types of ecosystems, and explores two critical processes that go on within them – energy flow and the cycling of matter. It is ideal for middle to upper level students of biology and other natural sciences. Show Less

Humans have caused massive changes to the natural balance of ecosystems around the globe. This clip examines some of the most dramatic and destructive ways in which people have impacted ecosystems – covering climate change, pollution, deforestation, and introduced species. Middle to upper level biology and other science students will find this an informative and engaging learning resource. Show Less

Our planet has four spheres – the lithosphere, biosphere, atmosphere, and hydrosphere. This clip provides an overview of vital biogeochemical cycles that occur across the four spheres, including the nitrogen, phosphorous, water, and carbon cycles. It is an excellent resource for middle to upper level students of biology and other natural sciences. Show Less

Molecules of pyruvate are transported from the cytoplasm of the cell into the mitochondria for the oxidation of pyruvate to acetyl co-enzyme A. Step one involves the decarboxylation of the pyruvic acid. In the step two, the two - carbon molecule is oxidised. In the third step, the oxidised acetyl group gets attached to co-enzyme A, thereby producing a molecule of acetyl co - enzyme A. Show Less

Carbohydrate is a biological molecule consisting of carbon (C), hydrogen (H), and oxygen (O) atoms. A carbohydrate molecule with three to seven carbon atoms and the corresponding number of hydrogen and oxygen atoms is called a monosaccharide. Two joined monosaccharides are called disaccharides. Polysaccharides are complex carbohydrates that are polymers of monosaccharides. Some important polysaccharides include starch, glycogen and cellulose. Show Less

Estuaries… many of us live on or near an estuary and maybe use it for boating or fishing or swimming, or even just for the view. Estuaries are often at the heart of coastal cities. But what’s their story? What’s happening under the water and why are our estuaries increasingly threatened? This programme defines what an estuary is, explains where they are found, and describes the ways that they are formed. It also includes a case study of a typical estuary and how tidal flow, salt water wedging, seasonal change, human use and pollution are effecting it. Show Less