How do plants obtain energy? How does food give us energy? We learn about matter and energy in organisms and ecosystems: the flow of energy in an ecosystem, how chemical changes turn matter (food) into energy for living organisms; biotic and abiotic factors in ecosystems; plants and energy, photosynthesis, energy transformation, energy producers and consumers; nutrients, digestion, metabolism, chemical respiration, metabolic rate, carnivores, omnivores, herbivores, food chains and food webs; matter, energy, organisms, and conservation of mass and energy in an ecosystem; environments, scavengers, decomposers, predators, prey; interdependence, Detailed graphics, diagrams and exciting video reinforce key concepts.