Chapter 2 Energy PPt. Notes

• What is the definition of energy?

  Energy is the capacity to change the position, composition, or temperature of matter.
• What happens when energy causes an object to move?

  It is a force that can accomplish work.
• What is potential energy?

  Potential energy is the energy of position or composition.
• Give an example of potential energy.

  River water held behind a dam contains potential energy.
• What is kinetic energy?

  Kinetic energy is the energy of motion.
• Provide an example of kinetic energy.


  River water rushing through a dam and downstream contains kinetic energy.
• Can energy be converted between potential and kinetic forms?

  Yes, energy can be converted back and forth between these two forms.
• When do energy conversions take place?

  Energy conversions take place whenever chemical bonds are broken or formed.
• What happens when high-energy bonds are converted to low-energy bonds?

  It releases kinetic energy.
• What does the first law of thermodynamics state?

  Energy cannot be created or destroyed.
• How does energy change in quality according to the second law of thermodynamics?

  Energy tends to change from a more-ordered to a less-ordered state as it changes form.
• What happens to the structure and energy of firewood when it is burned?

  The ash has less structure and useful energy compared to the firewood.
• What type of energy does the sun release?

  The sun releases energy across a wide range of the electromagnetic spectrum.
• What is the range of wavelengths that we can detect from the sun?

  We can only detect the range of wavelengths known as visible light.
• What are autotrophs?

  Autotrophs are organisms that use the sun’s radiation directly to produce their own food.
• What process do autotrophs use to produce food?

  They use a process called photosynthesis.
• What do autotrophs transform during photosynthesis?

  They transform molecules with low-energy bonds (water and carbon dioxide) into sugar molecules with high-energy bonds.
• Where does photosynthesis occur in plant cells?

  Photosynthesis occurs within cell organelles called chloroplasts.
• What pigment is involved in photosynthesis?

  A pigment called chlorophyll uses solar energy to initiate a series of reactions called light reactions.
• What do light reactions produce during photosynthesis?

  Light reactions split water molecules into hydrogen ions (H⁺), oxygen molecules (O₂), and small high-energy molecules of ATP and NADPH.
• What is the Calvin cycle in photosynthesis?

  The Calvin cycle reactions link together carbon atoms to form sugars.
• How can the overall process of photosynthesis be summarized?

  Plants take in water through their roots, absorb carbon dioxide from the air through their leaves, and harness the power of sunlight to generate sugar and oxygen.
• What is the overall reaction for cellular respiration?

  The overall reaction for cellular respiration is the exact opposite of photosynthesis.
• How much energy is released during cellular respiration compared to photosynthesis?

  The energy released is only about two-thirds of the input from photosynthesis.
• In which organisms does cellular respiration occur?

  Cell respiration occurs in all living things, both autotrophs and heterotrophs.
• What is geothermal energy?

  Geothermal energy is heat from deep within the planet.
• How does geothermal heat affect the Earth's surface?

  Radioisotopes decay and release heat, which gradually moves toward the surface and melts rock into magma.
• What can magma do when it reaches the surface?

  Magma can erupt from volcanoes, power plate tectonics, and heat groundwater.
• What are hydrothermal vents?

  Jets of water heated by geothermal energy can enter the cold ocean bottom through hydrothermal vents.
• How do organisms near hydrothermal vents obtain energy?

  They use the chemical potential energy in hydrogen sulfide (H₂S) to produce sugar, a process called chemosynthesis.
• What is the equation for chemosynthesis?

  The specific equation for chemosynthesis is not provided in the material.
• What is the movement of large plates of lithosphere called?

  It is called plate tectonics.
• What drives the movement of tectonic plates?

  Heat from the Earth drives loops of convection currents that cycle material upward and downward.
• How much movement do tectonic plates experience each year?

  Tectonic plates move about 2–15 centimeters every year.
• What occurs at divergent plate boundaries?

  At divergent plate boundaries, plates move apart as magma rises to the surface and cools.
• What happens at transform plate boundaries?

  At transform plate boundaries, plates slip and grind alongside each other, causing earthquakes.
• What occurs at convergent plate boundaries?

  Oceanic crust will dive downward in a process called subduction, or two continental plates will crush, bend, and buckle, creating mountain ranges.
• How do plate tectonics influence Earth's geography?

  Plate tectonics builds mountains, shapes the oceans, islands, and continents, and gives rise to earthquakes and volcanoes.
• What is the circum-Pacific belt also known as?

  The circum-Pacific belt is also called the "ring of fire."
• What is an earthquake?

  An earthquake is a sudden release of energy at a tectonic plate boundary.