bioenergetics

• what is bioenergetics?


  quantitative study of energy relationships and conversions in biological systems
• what is all life powered by on earth?

  solar energy, either directly/indirectly
• what do all organisms need in order to keep themselves alive and functioning?

  free energy
• how do organisms use sunlight as a source of energy for their metabolism

  chemical energy in the food ex: sugars
• what lead to the evolution of respiration

  presense of free oxygen
• when respiration releases energy, some energy gets formed into

  ATP molecules
• what is ATP


  Adenosine Triphosphate - ENERGY - is required for active transport. A kind of chemical link between catabolism and anabolism
• catabolism


  Metabolic pathways that break down molecules, releasing energy.
• anabolism


  Metabolic pathways that construct molecules, requiring energy.
• how do photosynthetic organisms use energy

  they use energy to synthesize organic compounds (like carbohydrates) that can't be formed without the input of energy
• photosynthesis acts as a ________________ process while respiration acts as a __________ process

  energy capturing

  energy releasing
• photosynthesis (definition)


  process in which energy poor inorganic oxidised compounds of carbon and water are reduced to energy rich carbohydrate using light energy that is converted into chemical energy by chlorophyll and other photosynthetic pigmentations
• respiration occurs during what time of day?

  both day and night
• photosynthesis occurs during what time of day?

  day only
• what is the main difference between photosynthesis and respiration?

  photosynthesis uses the products of respiration and respiration uses the products of photosynthesis
• what is the compensation point?

  when the rate of photosynthesis is equal to the rate of respiration. the oxygen released during photosynthesis is just the right amount for cellular respiration
• during the compensation point, as the light energy increases, ____

  so does the rate of photosynthesis and need for carbon dioxide
• aerobic respiration


  Respiration that requires oxygen
• what are the sites of photosynthesis in plants

  leaves
• how many chloroplasts are in a mesophyll cell?

  20-100
• chloroplasts have a ________ envelope

  double membrane
• what is the stroma? where is it located?

  fluid portion of the chloroplast; outside of the thylakoids
• membranes suspended in stroma

  thylakoids and chromosomes
• what are thylakoids?


  flat, disk like sacs membranes suspended in the stroma
• what is lumen/thylakoid interior space

  a fluid filled space which is separated from the stroma by the thylakoid membrane
• In some places, thylakoid sacs are stacked in columns called

  grana
• what is found in thylakoid membranes

  chlorophyll and other photosynthetic pigments
• what does chlorophyll do in thylakoid membranes


  impart green color into the plant
• Electron Transport Chain (ETC)


  also a part of the membranes found in thylakoids
• how are thylakoid membranes involved in ATP synthesis?


  chemiosmosis
• Chemiosmosis


  A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.
• what is used to synthesize sugar in the stroma of the chloroplast?

  ATP and NADPH
• what absorbs light energy and then gets converted into chemical energy

  chlorophyll
• light can only work in chloroplasts if ?


  it is absorbed
• what are pigments?


  light absorbing molecules
• what are the sizes of pigments?

  380-750 nm
• spectrophotometer


  used to measure relative abilities of different pigments to absorb different wavelengths of light
• What is an absorption spectrum?


  a graph plotting absorption of life of different wavelengths by pigment
• what is the main pigment in thylakoid membranes?
• what other pigments are in thylakoid membranes

  yellow, red, orange