The Cell Mitochondria Chloroplasts PPT 2 Part I

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The Cell: Mitochondria & Chloroplasts PPT 2

The Cell: Mitochondria & Chloroplasts PPT 2

Part I Preview to Cell Respiration: Mitochondria 2005 -2006

Part I Preview to Cell Respiration: Mitochondria 2005 -2006

Overview § Mitochondria & chloroplasts : organelles that convert energy to forms that cells

Overview § Mitochondria & chloroplasts : organelles that convert energy to forms that cells can use for work mitochondria: from glucose to ATP u chloroplasts: from sunlight to ATP & carbohydrates u § ATP = active energy § carbohydrates = stored energy ATP +

Mitochondria & Chloroplasts Important to see the similarities u transform energy § generate ATP

Mitochondria & Chloroplasts Important to see the similarities u transform energy § generate ATP double membranes = 2 membranes u semi-autonomous organelles u § move, change shape, divide u internal ribosomes, DNA & enzymes 2005 -2006

Mitochondria § Function cellular respiration u generate ATP u § from breakdown of sugars,

Mitochondria § Function cellular respiration u generate ATP u § from breakdown of sugars, fats & other fuels § in the presence of oxygen w break down larger molecules into smaller to generate energy = catabolism w generate energy in presence of O 2 = aerobic respiration

Mitochondria Structure u 2 membranes § smooth outer membrane § highly folded inner membrane

Mitochondria Structure u 2 membranes § smooth outer membrane § highly folded inner membrane w the cristae u u fluid-filled space between 2 membranes internal fluid-filled space § mitochondrial matrix § DNA, ribosomes & enzymes Why 2 membranes? increase surface area for membranebound enzymes that synthesize ATP 2005 -2006

Mitochondria 2005 -2006

Mitochondria 2005 -2006

Membrane-bound Enzymes 2005 -2006

Membrane-bound Enzymes 2005 -2006

Dividing Mitochondria Who else divides like that? What does this tell us about the

Dividing Mitochondria Who else divides like that? What does this tell us about the evolution of eukaryotes? 2005 -2006

Mitochondria § Almost all eukaryotic cells have mitochondria u u there may be 1

Mitochondria § Almost all eukaryotic cells have mitochondria u u there may be 1 very large mitochondrion or 100 s to 1000 s of individual mitochondria number of mitochondria is correlated with aerobic metabolic activity § more activity = more energy needed = more mitochondria What cells would have a lot of mitochondria? active cells: • muscle cells • nerve cells 2005 -2006

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Part II The Chloroplast – 2005 -2006

Part II The Chloroplast – 2005 -2006

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2005 -2006

Chloroplasts § Chloroplasts are plant organelles u They are in a class of plant

Chloroplasts § Chloroplasts are plant organelles u They are in a class of plant structures called plastids § amyloplasts w store starch in roots & tubers § chromoplasts w store pigments for fruits & flowers § chloroplasts w store chlorophyll & function in photosynthesis w in leaves, other green structures of plants & in eukaryotic algae 2005 -2006

Chloroplasts § Structure u 2 membranes § outer membrane § inner membrane u internal

Chloroplasts § Structure u 2 membranes § outer membrane § inner membrane u internal fluid-filled space = stroma § DNA, ribosomes & enzymes § thylakoids = membranous sacs where ATP is made § grana = stacks of thylakoids Why internal sac membranes? increase surface area for membrane-bound enzymes that synthesize ATP 2005 -2006

Membrane-bound Enzymes 2005 -2006

Membrane-bound Enzymes 2005 -2006

Chloroplasts § Function photosynthesis u generate ATP & synthesize sugars u § transform solar

Chloroplasts § Function photosynthesis u generate ATP & synthesize sugars u § transform solar energy into chemical energy § produce sugars from CO 2 & H 2 O § Semi-autonomous § moving, changing shape & dividing § can reproduce by pinching in two Who else divides like that? bacteria! 2005 -2006

Chloroplasts Why are chloroplasts green? 2005 -2006

Chloroplasts Why are chloroplasts green? 2005 -2006

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2005 -2006

Mitochondria & chloroplasts are different from other organelles § Organelles not part of endomembrane

Mitochondria & chloroplasts are different from other organelles § Organelles not part of endomembrane system § Grow & reproduce u semi-autonomous organelles § Proteins primarily from free ribosomes in § cytosol & a few from their own ribosomes Own circular chromosome u directs synthesis of proteins produced by own internal ribosomes Who else has a circular chromosome no bound within a nucleus? bacteria 2005 -2006

1981 | ? ? Endosymbiosis theory § Mitochondria & chloroplasts were once free living

1981 | ? ? Endosymbiosis theory § Mitochondria & chloroplasts were once free living bacteria u engulfed by ancestral eukaryote § Endosymbiont u cell that lives within another cell (host) § as a partnership § evolutionary advantage for both w one supplies energy w the other supplies raw materials & protection Lynn Margulis U of M, Amherst 2005 -2006

Endosymbiosis theory Evolution of eukaryotes 2005 -2006

Endosymbiosis theory Evolution of eukaryotes 2005 -2006

Quad Set 7/1 Do all questions on page 138, 1 -12 Write questions and

Quad Set 7/1 Do all questions on page 138, 1 -12 Write questions and answers in your book! + handout A 2005 -2006