Photosynthesis and Cellular Respiration

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Photosynthesis and Cellular Respiration
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Importance of the Cell Membrane

• Between every cell and its environment is a filmy
  sheet, a membrane composed of lipids and
  proteins.
• The regulation of movement of materials from 1
  area to another is one of the most important
  functions of a membrane.

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Cell Membranes

• Are refered to as a phospholipid bilayer
• There are protein molecules embedded throughout
  the layer
• Cholesterol is a combination of a steroid (lipid)
  and an alcohol which gives stiffness to the
  membrane.

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Processes used to move materials.

• Diffusion
• the random movement of molecules from an area of
  high concentration to low concentration (towards
  a state of even distribution)
• Rate of diffusion depends on
• Size of the molecules
• Temperature
• Concentration difference

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• The difference between high and low regions is
  called the concentration gradient.
• When there is even distribution, this is called
  equilibrium.
• Arrows represent the direction of concentration
  gradient.
• An example of this would be the diffusion of
  oxygen into the cells and carbon dioxide
  diffusing out of the cells.
• http//www.biosci.ohiou.edu/introbioslab/Bios170/d
  iffusion/Diffusion.html
• http//www.stolaf.edu/people/giannini/flashanimat/
  transport/diffusion.swf

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• Facilitated diffusion
• The use of specialized proteins to transport
  substances across a membrane.
• http//www.d.umn.edu/sdowning/Membranes/diffusion
  animation.html

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• Osmosis (Page 95-97)
• The diffusion of water across a selectively
  permeable membrane from a region of high
  concentration to a region of low concentration.
• http//highered.mcgraw-hill.com/sites/0072495855/s
  tudent_view0/chapter2/animation__how_osmosis_works
  .html

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• a. Hypertonic solutions
• -high concentration of water molecules is higher
  in the inside of a cell.
• -water molecules move out, making the cell
  smaller
• http//www.tvdsb.on.ca/westmin/science/sbi3a1/Cell
  s/Osmosis.htm

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• Hypotonic solutions
• -concentration of water is higher on the outside
  of the cell.
• -causes the water to move inside, which makes
  the cell larger
• http//www.tvdsb.on.ca/westmin/science/sbi3a1/Cell
  s/Osmosis.htm

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• Isotonic solutions
• -when the concentration of water is the same on
  the inside and the outside of the cell.
• -cell does not change in size.

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Osmosis Lab
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Active and Passive Transport

• Passive
• No energy is required to move substances across a
  membrane.
• The direction of movement is caused by the
  concentration gradient.

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• Active
• Using energy to go against the concentration
  gradient.
• http//www.northland.cc.mn.us/biology/Biology1111/
  animations/active1.swf
• Make special note on endocytosis made using a
  vesicle (pinocytosis and phagocytosis)
• Example what the kidney does to make urine

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• http//student.ccbcmd.edu/courses/bio141/lecguide/
  unit3/eustruct/phagocyt.html
• http//student.ccbcmd.edu/courses/bio141/lecguide/
  unit3/eustruct/pinocyt.html

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Cell Parts Review (Eukaryotic cells)

• Cell wall
• Cell membrane
• Nucleus
• Nucleolus
• Cytoplasm
• Endoplasmic reticulum
• Ribosomes
• Golgi bodies (apparatus)
• Mitochondria
• Vacuoles

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Cellular Respiration

• Is a process by which cells release energy from
  the basic molecules of food to make energy rich
  ATPs (adenosine triphosphate) from ADP (di)
• respiration comes from the taking in of oxygen
  (aerobic) and the production of carbon dioxide as
  a byproduct.

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• Process takes place mostly in the mitochondria of
  a cell.
• ATP is refered to as money in the bank as this
  energy rich molecule can be used later, when
  needed.

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Stages to Cellular Respirationhttp//www.qcc.cuny
.edu/BiologicalSciences/Faculty/DMeyer/respiration
.html

• Glycolysis (occurs in the cytoplasm)
• primary food molecule utilized is glucose
  (C6H12O6)
• Glucose is split into two 3 carbon molecules
  (pyruvic acid)
• Energy (ATP) is needed at this step.
• Some ATP is produced in this stage.
• Net gain of 2 ATP molecules

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2. Krebs Cycle (occurs in the mitochondrion)

• - both pyruvic acids (3 Cs) are disassembled
  and CO2 molecules are formed.
• - two 2 C acetic acids are produced.
• - each acetic acid combines with a 4 C acid to
  produce citric acid (6 Cs)
• - H atoms are released of which coenzyme NAD
  (nicotinamide adenine dinucleotide), carries
  hydrogen (electrons) to the third stage.
• - Energy (ATP) is needed at this step
• - Some ATP is produced in this stage.
• - Net gain of 2 ATP molecules
• - a four C molecule remains

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3. Electron Transport Chain (mitochondria)

• - the hydrogens are used in a series of
  stepwise reactions that produce most of the ATPs
  (34).
• - the hydrogen and oxygen form to produce water
  as another byproduct.

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Overall Equation

• C6H12O6 6O2---gt 6CO2 6H2O 36ATP

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Fermentation

• Oxygen is needed in cellular respiration to
  remove hydrogen
• If hydrogen cant be removed, pyruvic acid can
  not be broken down.
• In plants, bacteria and yeasts alcohol
  fermentation occurs.
• In animals (especially in the muscles) the
  hydrogen reacting with pyruvic acid produces
  lactic acid which leads to muscle fatigue.

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Group/Individual Assignment

• From 1 to a maximum of 3 people
• Develop a 3D interactive model on 1 of the
  following
• Glycolysis and Krebs cycle
• Krebs cycle and ETC
• Light Reaction
• Dark Reaction

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Requirements

• Must include all necessary information, as well
  as 3-5 (good, better, best) additional details
  researched by you.
• The model must be interactive.
• The model must be labeled correctly.

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Marking Scheme
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Photosynthesis

• http//highered.mcgraw-hill.com/sites/0072437316/s
  tudent_view0/chapter10/animations.html
• Plants (autotrophs) make their own food by using
  the energy of the sun to drive a chemical
  reaction in the plant.
• There are 2 reactions involved in the chloroplast.

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1. Light Dependent Reaction

• Takes place only in the light as well requires
  water.
• Occurs in the thylakoid of the chloroplast.

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• Light excitation of photosystems I and II (which
  are arrangements of pigment molecules) breaks
  water into positive hydrogen and negative
  hydroxyl ions (this is called photolysis).
• Hydroxyl ions give up their electrons to the
  pigments of the leaf.
• Oxygen is released as a byproduct.

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• This reaction also takes the high energy
  electrons from hydrogen to combine with NADPH
  (enzyme) to form NADPH (which will be needed in
  the 2nd stage).
• The high energy electrons will also change ADP to
  ATP

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Calvin Cycle (Dark Reaction)

• Can take place without light.
• Occurs in the stroma of the chloroplast

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• Reaction requires the energy from ATP and NADPH
  as well as CO2.
• Carbon fixation occurs in which the inorganic C
  from carbon dioxide is fixed into organic
  molecules (sugar).
• The C from CO2 combines with RuBP (ribulose
  biphospahte (a 5 C molecule).
• Now this 6 C molecule splits into two 3-C
  molecules of PGA (phosphoglycerate).

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• The energy from ATP and the NADPH changes PGA
  into 2 3-C sugars of PGAL (phosphoglyceraldehyde).
  
• 1 PGAL is kept in the cycle and reconverted to
  RuBP
• 1 PGAL is used for energy storage, or immediately
  for cell activity use.
• http//www.sinauer.com/cooper/4e/animations0305.ht
  ml

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Overall Equationhttp//www.cix.co.uk/argus/Dream
bio/photosynthesis/photosynthsis20animation.htm