CELLULAR ENERGY

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CHAPTER 8

• CELLULAR ENERGY

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• SECTION 8.1 HOW ORGANISMS OBTAIN ENERGY
• MAIN IDEA All living organisms use energy to
  carry out all biological processes.
• QUESTIONS What is energy?
• Why do living things need energy?
• How do humans obtain energy?

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• TRANSFORMATION OF ENERGY
• Chemical reactions and processes in your cells
  are continuous, even when you dont think you are
  using any energy.
• Macromolecules are assembled and broken down,
  substances are transported across cell membranes
  and genetic instructions are sent.
• All require energy
• Energy is the ability to do work.

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• LAWS OF THERMODYNAMICS
• 1st law of thermodynamics is the law of
  conservation of energy, which states that energy
  can be converted from one form to another, but
  cannot be created nor destroyed.

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• AUTOTROPHS AND HETEROTROPHS
• Autotrophs make their own food using energy from
  the sun.
• Convert light energy from the sun into chemical
  energy.
• Heterotrophs need to eat food to obtain energy

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• METABOLISM
• Metabolism is all of the chemical reactions in a
  cell.
• ATP THE UNIT OF CELLULAR ENERGY
• Adenosine triphosphate (ATP) is the most
  important biological molecule that provides
  chemical energy.

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• ATP STRUCTURE
• ATP is a multipurpose storehouse of chemical
  energy that is used by cells in a variety of
  reactions.
• Most abundant energy carrier molecule in cells
  found in all types of organisms.
• ATP is a nucleotide made up of a adenine base, a
  ribose sugar, and 3 phosphate groups.
• QUESTION What macromolecule group does ATP
  belong in?

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• ATP FUNCTION
• ATPs function is to release energy when the bond
  between the 2nd and 3rd phosphate groups are
  broken
• Forms adenosine diphosphate (ADP) and a free
  phosphate group
• Energy is released

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• SECTION 8.2 PHOTOSYNTHESIS
• MAIN IDEA Light energy is trapped and converted
  into chemical energy during photosynthesis.
• QUESTIONS What is the benefit of photosynthesis
  for humans?
• How does photosynthesis benefit plants?

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• OVERVIEW OF PHOTOSYNTHESIS
• Photosynthesis is a process where light energy is
  converted into chemical energy.
• Chemical equation for photosynthesis is
• light
• 6CO2 6H2O C6H12O6
  6O2
• Photosynthesis occurs in 2 phases
• Phase 1 light dependent reactions where light
  energy is absorbed and converted into chemical
  energy in the form of ATP and NADPH
• Phase 2 light independent reactions where the
  ATP and NADPH that was made in phase one are used
  to make glucose.
• After glucose is produced it can be joined with
  other simple sugars to form larger molecules like
  starches
• Can also make proteins, lipids, and nucleic
  acids.

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• PHASE 1 LIGHT REACTIONS
• Chloroplasts capture light energy in
  photosynthesis.
• Mainly found in the cells of leaves.
• Disk-shaped organelles that contain 2 main
  compartments essential for photosynthesis.
• Thylakoids flattened, saclike membranes that
  are arranged in stacks called grana
• Light dependent reactions take place within the
  thylakoids.
• Stroma are fluid filled spaces outside the grana.
• Light independent reactions in phase 2 take place
  here.
• Pigments are light absorbing colored molecules
  that are found in the thylakoid membranes of the
  chloroplasts.
• Different colored pigments absorb specific
  wavelengths of light.
• Chlorophylls
• Carotenoids

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• PHASE 2 THE CALVIN CYCLE
• In the Calvin Cycle energy gets stored in organic
  molecules like glucose.

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• SECTION 8.3 CELLULAR RESPIRATION
• MAIN IDEA Living organisms obtain energy by
  breaking down organic molecules during cellular
  respiration
• QUESTION Is air the same as oxygen?
• If it is not the same, how is air different from
  oxygen?

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• OVERVIEW OF CELLULAR RESPIRATION
• Organisms obtain energy by a process called
  cellular respiration.
• During cellular respiration electrons are
  collected from carbon compounds, like glucose,
  and use that energy to make ATP.
• ATP is used to provide energy for cells to do
  work.
• Equation for cellular respiration is the opposite
  of the equation for photosynthesis.
• C6H12O6 6O2 6CO2
  6H2O
• Cellular respiration has 2 parts
• Glycolysis
• Anaerobic process (does not require oxygen)
• Aerobic respiration (Requires oxygen)
• Includes
• Krebs Cycle
• Electron transport

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• GLYCOLYSIS
• Glycolysis is the process where glucose is broken
  down in the cytoplasm.
• 2 ATP molecules are required to start the
  reactions.
• Produces
• 2 molecules of ATP and 2 molecules of NADH for
  each molecule of glucose that is broken down.
• 2 pyruvate molecules

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• KREBS CYCLE
• The 2 pyruvate molecules are transported to the
  mitochondria.
• In the mitochondria with the help of oxygen the
  pyruvate is broken down into
• 6 CO2
• 2 ATP
• 8 NADH
• 2 FADH2

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• ELECTRON TRANSPORT
• Electron transport is the final step in the
  breakdown of glucose.
• Electrons move along the mitochondrial membrane
  from one protein to another.
• The electron transport produces
• 32 ATP
• In eukaryotes one molecule of glucose yields 36
  ATPS under ideal conditions.

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• PHOTOSYNTHESIS AND CELLULAR RESPIRATION
• Photosynthesis and cellular respiration are 2
  important metabolic pathways that cells use to
  obtain energy.
• Photosynthesis products are oxygen and glucose,
  but these are the reactants for cellular
  respiration
• Cellular respiration products are carbon dioxide
  and water, but these are the reactants for
  photosynthesis