Mitochondria and Chloroplasts

  1. What is the evolutionary origin?
    • endosymbiont theory
    • Early ancestor of eukaryotic cells engulfed an oxygen-using nonphotosynthetic prokaryotic cell
    • The engulfed cell formed symbiotic relationship with host cell, becoming an endosymbiont
    • Merged into single organism
  2. Support for endosymbiont theory.
    • Two membranes
    • Contain own ribosomes and circular DNA molecules attached to inner membranes
    • - DNA programs synthesis of some of their own proteins
    • Autonomous (grow and reproduce within cell)
  3. Mitochondria:
    a) sites of__, the metabolic process that uses oxygen to generate ATP by extracting energy from sugars, fats, etc.
    b) Which cells have these?
    • cell respiration
    • all eukaryotic cells; number varies on activity
  4. Structure of mitochondria
    • two membranes: phospholipid bilayer w. variety of proteins
    • - outer: smooth
    • - inner: convoluted with infoldings called cristae, which give a higher surface area--> enhancing productivity (structure meets function)
  5. Explain inner membrane of mitochondria.
    • 1. Divides mitochondrion into two internal compartments:
    •    a. Intermembrane space: narrow region between inner and outer membranes
    •    b. Mitochondrial matrix
    •           i. Contains different enzymes (catalyze some cellular respiration steps), DNA, and ribosomes
    • They move around, fuse, or divide into two
  6.                                                               i.      Chloroplasts are the sites of __
    1.      Convert __energy to __energy
    2.      Contain __, __, and other molecules that function in photosynthesis
    3.      __-shaped; changeable; mobile; divide
    • photosynthesis
    • solar
    • chemical
    • chlorophyll
    • enzymes
    • Lens
  7. 1.      Contents of chloroplast are partitioned from cytosol by envelope consisting of __separated by __
    2.      Membranous system in the form of flattened, interconnected sacs called __
    a.      May be stacked like poker chips, called __
                                                                                                                                          i.      Fluid outside the thylakoid is the __, which contains __
    3.      Membranes divide chloroplast into three compartments:
    a.    ___
    b.   __
    c.    ___
    • two membranes
    • intermembrane space
    • thylakoids
    • granum
    • stroma
    • DNA and ribosomes and enzymes
    •   Intermembrane space
    • stroma
    • thylakoid space
  8. 1.      Specialized member of __, plant organelles
    a.      __is colorless organelle that stores __in roots ad tubers
    b.      __has __that give fruits and flowers their orange and yellow hues 
    • plastids
    • Amyloplast
    • starch
    • Chromoplast
    • pigments
  9. a.      Peroxismes
                                                                  i.      Specialized metabolic compartment bounded by a single membrane
                                                                ii.      Contain enzymes that remove __ from __and transfer to __to produce __
    • hydrogen atoms
    • substrates
    • O2
    • H2O2
  10. Functions of Peroxisomes:
    • 1) use oxygen to break fatty acids that are transported to mitochondria and used as fuel
    • 2) detoxify alcohol and other harmful compounds by transferring H from poisons to oxygen in liver
    • 3) contain enzymes that convert hydrogen peroxide into water= structure meets function becauase away from other cell compponents
  11. Glyoxysomes
    1) Location?
    2) Function?
    • 1)  found in fat storing tissues of plant seeds
    • 2) initiate conversion of FA to sugar
  12. How do perxisomes grow larger?
    by incorporating proteins made in cytosol and Er and lipids within self
Card Set
Mitochondria and Chloroplasts