genbio

• ATP- ADENOSINE TRIPHOSPHATE
• THREE PARTS OF ATP

  • ADENINE, RIBOSE, PHOSPHATE
• 
  

  PARTS OF ATP CYCLE

  PHOSPHATE REMOVED, AND ENERGY RELEASED
• What is the main chemical compound used by cells for energy?

  Adenosine triphosphate (ATP)
• What part of ATP is key to its energy storage ability?

  The phosphate group
• How does ATP release energy?

  By breaking bonds between phosphate groups
• What is the difference between endergonic and exergonic reactions?

  Endergonic absorbs energy; exergonic releases energy
• What is energy coupling?

  Transfer of energy between chemical reactions
• What are the two classifications of chemical reactions?

  • Exergonic reaction
  • Endergonic reaction
• What characterizes an exergonic reaction?

  It has negative Gibbs free energy
• What characterizes an endergonic reaction?

  It has positive Gibbs free energy
• Compare the energy characteristics of exergonic and endergonic reactions.

  • Exergonic:
  • High energy of reactants
  • Low energy of products
  • Does not require energy
  • Releases energy
  • Spontaneous (AG < 0)
  • Endergonic:
  • Low energy of reactants
  • High energy of products
  • Requires energy
  • Absorbs energy
  • Nonspontaneous (AG > 0)
• What is metabolism?

  Chemical reactions changing food into energy
• What are the two types of metabolic pathways?

  1. Anabolism: Builds molecules, requires energy
  2. Catabolism: Breaks down molecules, releases energy
• What is photosynthesis?

  Metabolic process converting light energy to chemical energy
• What are autotrophs known as?

  Producers
• What are heterotrophs known as?

  Consumers
• What are the basic concepts of photosynthesis?

  1. Water absorbed by roots via xylem
  2. Carbon dioxide enters through stomata
  3. Chlorophyll absorbs light energy
  4. Hydrogen and carbon dioxide produce glucose
  5. Oxygen is released as a waste product
  6. Glucose is transported via phloem and stored as starch
• What is the organelle where photosynthesis occurs?

  Chloroplast
• What are the functions of a chloroplast?

  • Site of photosynthesis
  • Double-membraned
  • Contains its own DNA
  • Found in green tissue of plants
• What is the structure of a chloroplast?

  1. Outer membrane: Freely permeable
  2. Inner membrane: Highly selective
  3. Stroma: Protein-rich ground substance
  4. Thylakoid: Membrane-bound disks for light reactions
  5. Granum: Stacks of thylakoids
  6. Intergranal lamellae: Connect granum
• What are the functions of biochromes?

  • Give colors to flowers, leaves, and fruits
  • Play a key role in photosynthesis
  • Control growth and development
  • Absorb energy from sunlight
• What are accessory pigments?

  • Absorb wavelengths of light not absorbed by chlorophyll
  • Enable plants to utilize more sunlight energy
• What types of chlorophyll are found in higher order plants?

  • Chlorophyll a
  • Chlorophyll b
• What is the role of carotenoids in plants?

  Accessory light-harvesting pigments
• What are the types of carotenoids?

  • Reflect red to orange light
  • Xanthophyll recognized by yellow coloration
• Where do light-dependent reactions occur?

  In the thylakoid membrane
• What happens during light-dependent reactions?

  • Light energy converts to chemical energy (ATP and NADPH)
  • Involves two photosystems and an electron transport chain
• What are the components of photosystems?

  • Absorbing pigment
  • Antennae pigment
  • Reaction center
• What is the reaction center of Photosystem II?

  P680
• What is the reaction center of Photosystem I?

  P700
• What are the stages of light-dependent reactions?

  1. Excitation of photosystems and photolysis of water
  2. Generation of ATP by electron transport chain
  3. Formation of NADPH
• What occurs during the excitation of photosystems?

  Electrons are transferred to electron acceptors
• What is photolysis of water?

  Splitting of water molecules into H+ and O2
• How is ATP generated in light-dependent reactions?

  Through chemiosmosis via ATP synthase
• What is NADPH formed from?

  Electrons and H+ attaching to NADP
• Where do light-independent reactions occur?

  In the stroma
• What are the phases of light-independent reactions?

  1. Carbon Fixation
  2. Reduction
  3. Regeneration of CO2 acceptor
• What is the role of RuBisCO in carbon fixation?

  Catalyzes the reaction of RuBP and CO2
• What happens during the reduction phase?

  Organic compounds are converted to simple sugars