Energy Transfers In and Between Organisms

• Why do organisms need energy for life processes?

  Energy is essential for biological processes.
• What do plant cells need energy for?

  Photosynthesis, active transport, DNA replication, cell division, protein synthesis.
• What do animal cells need energy for?

  Muscle contraction, body temperature maintenance, active transport, DNA replication, cell division, protein synthesis.
• What is photosynthesis?

  Process of making glucose from light energy.
• What is the overall equation for photosynthesis?

  6CO₂ + 6H₂O (+ Energy) → C₆H₁₂O₆ + 6O₂
• How do plants release energy stored in glucose?

  Through respiration.
• How do animals obtain glucose?

  By eating plants or other animals.
• What is respiration?

  Process of releasing energy from glucose.
• What are the two types of respiration?

  Aerobic and anaerobic respiration.
• What does aerobic respiration produce?

  Carbon dioxide, water, and energy.
• What is the overall equation for aerobic respiration?

  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O (+ Energy)
• What does anaerobic respiration produce in plants and yeast?

  Ethanol and carbon dioxide.
• What does anaerobic respiration produce in humans?

  Lactate.
• What is ATP?

  Adenosine triphosphate, energy carrier.
• How is ATP synthesized?

  From ADP and inorganic phosphate using energy.
• What enzyme catalyzes the synthesis of ATP?

  ATP synthase.
• How does ATP release energy?

  By hydrolysis back into ADP and inorganic phosphate.
• What enzyme catalyzes the hydrolysis of ATP?

  ATP hydrolase.
• What are the specific properties of ATP?

  Stores/releases small energy, soluble, easily broken down.
• What is a metabolic pathway?

  A series of reactions controlled by enzymes.
• What is phosphorylation?

  Adding phosphate to a molecule.
• What is photophosphorylation?

  Adding phosphate using light energy.
• What is photolysis?

  Splitting a molecule using light energy.
• What is photoionisation?

  Exciting electrons in a molecule using light.
• What is hydrolysis?

  Splitting a molecule using water.
• What is decarboxylation?

  Removal of carbon dioxide from a molecule.
• What is dehydrogenation?

  Removal of hydrogen from a molecule.
• What are redox reactions?

  Reactions involving oxidation and reduction.
• What happens when a molecule is reduced?

  It gains electrons and may gain hydrogen.
• What happens when a molecule is oxidised?

  It loses electrons and may lose hydrogen.
• What does OILRIG stand for?

  Oxidation Is Loss, Reduction Is Gain.
• What is a coenzyme?

  A molecule that aids enzyme function.
• How do coenzymes work?

  By transferring a chemical group between molecules.
• What is NADP?

  A coenzyme used in photosynthesis.
• What do NAD and FAD do in respiration?

  Transfer hydrogen between molecules.
• What is the function of coenzyme A?

  Transfers acetate between molecules.
• What happens when hydrogen is transferred between molecules?

  Electrons are transferred too.
• Where does photosynthesis take place?

  In the chloroplasts of plant cells.
• What are chloroplasts?

  Flattened organelles surrounded by a double membrane.
• What are thylakoids?

  Fluid-filled sacs stacked in chloroplasts.