Paul Andersen explains how the photons emitted from or absorbed by an atom or nuclei is directly related to electrons moving between energy level. Absorption and emission are a direct result of the conservation of energy.

Paul Andersen explains the major elements in the endocrine system. He explains how glands produce hormones which target cells. He differentiates between water soluble and lipid soluble hormones. He then describes the hormones and actions of ten glands: pineal, anterior pituitary, posterior pituitary, thyroid, parathyroid, pancreas, adrenal cortex, adrenal medulla, testes and ovaries.

Paul Andersen explains how eukaryotic cells were formed through a process of endosymbiosis. He describes how aerobic bacteria became mitochondria and cyanobacteria became chloroplasts. He mentions an example of symbiosis that occurs today and mentions the importance of Dr. Lynn Margulis in the development of this modern theory.

In this video Paul Andersen explains how heat can be absorbed in endothermic or released in exothermic reactions. An energy diagram can be used to show energy movements in these reactions and temperature can be used to measure them macroscopically. Do you speak another language?

In this video Paul Andersen explains how energy can enter and leave a system. The amount of energy a substance can receive through heating or lose through cooling is measured using the specific heat capacity.

Paul Andersen explains the different forms and units for energy. A discussion of the laws of thermodynamics is also included. Sample conversion problems using dimensional analysis is also included.

Paul Andersen explains how humans have consumed energy through history and may consume energy in the future. Sources of energy have included food, animals, wood, wind, coal, oil, and natural gas. However non-renewable energy source eventually lead to an energy crisis as supplies go down or prices go up.

Paul Andersen explains how energy flows in ecosystems. Energy enters via producers through photosynthesis or chemosynthesis. Producers and consumers release the energy from food through cellular respiration. An explanation of gross primary productivity and net primary productivity are included.

Paul Andersen explains how the law of conservation of energy applies to both energy and mass. Einstein showed that mass and energy are equivalent and that the amount of energy contained within matter can be calculated using the famous equation E=mc^2.

The best form of energy available to the world is energy reduction. In this video Paul Andersen explains how energy conservation and energy efficiency and be used to decrease energy during peak demand. Tiered and variable pricing, as well as sustainable design are also discussed.

In this video Paul Andersen explains how energy can be transferred from one system to another. In a closed system the energy can be transferred as either work or heat. Thermal energy transfer is know as energy transfer through heat. During energy transfer the energy of the entire system is conserved.

Mr. Andersen defines the terms energy, work and power. He also uses a simple example to calculate both work and power.

In this video Paul Andersen explains how the enthalpy of a reaction can be released in an exothermic or consumed in an endothermic reaction. According to Hess's law if the reaction is reversed the sign of the enthalpy of reaction is also reversed.

In this video Paul Andersen explains that entropy is simply the dispersion of matter or energy. He begins with a series of video that show the natural direction of processes. According to the second law of thermodynamics the entropy may never decrease in a closed system.

Paul Andersen explains how economic models, like supply and demand, can be applied to environmental systems. The market forces will not protect environmental services until proper valuation and externalities are established. The wealth of a nation can be more accurately measured through the sustainability of the economic model.

Paul Andersen explains how living organisms exchange matter with the environment. The importance of the surface area to volume ratio is emphasized using a simple mathematical model. The essential chemicals for life; water, carbon, nitrogen and phosphorus are described. Each of these elements are vital to the four major macromolecules.

Paul Andersen outlines the AP Environmental Science course. He explains how environmental science studies the interaction between earth and human systems. A planetary boundary model is used to explain the importance of sustainability. The importance of science practices and knowledge of the APES format is also included.

Paul Andersen explains how matter and energy are conserved within the Earth's system. Matter is a closed system and Energy is open to the surroundings. In natural systems steady state is maintained through feedback loops but can be be affected by human society.

Paul Andersen starts with a brief description of enzymes and substrates. He then explains how you can measure the rate of an enzyme mediated reaction. Catalase from yeast is used to break hydrogen peroxide down into water and oxygen. He also explains how temperature and pH could affect the rate of a reaction.

Paul Andersen explains how enzymes are used to break down substrates. The correct shape of the active site allows a key/lock fit between the enzyme and the substrate. The enzyme catalase is used to break down hydrogen peroxide. The importance of cofactors and coenzymes is emphasized.