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254 Cards in this Set
- Front
- Back
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Cytoskeleton
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Contains actin filaments, intermediate filaments, microtubules; maintain cell shape and allow cell and organelles to move
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Actin Filaments
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SMALLEST OF FIBERS; Long, extremely thin, flexible fibers structural role (complex web under plasma membrane), formation of pseudopods; moving stuff around, cytoplasmic streaming; cell division (pinch mother cell in two after mitosis)
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Pseudopods
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Formed by actin filaments, extensions that allow certain cells to move in amoeboid fashion
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Motor Molecules
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Proteins that can attach, detach, reattach farther along an actin filament; pulls actin filaments along
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Microvili
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Intestinal cell projections
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Myosin
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Intermediate filaments
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Intermediate Filaments
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Intermediate in size, rope-like assembly; support nuclear envelope; cell-cell junctions; support cell; vary in chemical composition
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Microtubules
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2x larger than intermediate filaments; 2 globular proteins (a and B); under control of Microtubule Organizing Center (MTOC)- most important is centrosome; proteins kinesin and dynein to cause movement of organelles
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Centrioles
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Only in animal cells (one pair per cell); short hollow cylinders (9 overlapping triplets); Located in centrosome, right angles to one another; Separate during mitosis to determine plane of division!
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Basal Bodies
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Organelle that lies at the base of cilia and flagella and may direct the organization of microtubules within these structures (centrioles give rise to basal bodies)
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Cilia
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Move in waves like oars; hair-like projections from cell surface; cell movement!; 9 + 2 pattern used by all cilia and flagella; much shorter than flagella; respiratory system (sweep mucous/trap materials); sweep eggs into ovaries
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Flagella
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Propeller or corkscrew movement; hair-like projections from cell surface; cell movement!; 9 + 2 pattern used by all cilia and flagella; much shorter than flagella; respiratory system (sweep mucous/trap materials); sweep eggs into ovaries
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Membrane Functions
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Outer boundary; Structural support; sensitivity (response); communication; regulation; chemical reactions; defense; compartmentalization
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Plasma Membrane
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Separates Intracellular Fluid (ICF) from extracellular fluid (ECF); phospholipid bilayer
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Phospholipid Bilayer
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70% of all membranes; external surface hydrophilic polar heads; nonpolar, hydrophobic fatty acid tails in between
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Cholesterol
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Lipid found in animal plasma membrane, modifies fluidity of membrane (higher temperature cholesterol stiffens membrane (fluidity decreases), lower temperatures prevents membrane from freezing (fluidity increases))
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3 Components of Fluid-Mosaic Model
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Basic membrane referred to as phospholipid bilayer; protein molecules embedded (move laterally); cholesterol stabilizes clusters of phospholipids
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Peripheral Proteins
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Found on inner membrane; attach to one surface
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Integral Proteins
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Partially or wholly embedded, physically connected (transmembrane)
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Glycolipids
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Lipids with attached carbohydrate chains
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Glycoproteins
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Proteins with attached carbohydrate chains
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Clycocalyx
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"Sugar coating" on proteins; protects the cell; adhesion between cells; signaling molecules; cell to cell recognition; allows formation of antibodies for foreign cells
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Membrane Proteins: Channel Proteins
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Gated channels allow certain molecules; tubular; allow passage of molecules
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Membrane Proteins: Carrier Proteins
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Combine with substance to be transported; assist passage of molecules
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Membrane Proteins: Cell Recognition Proteins
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Unique chemical ID for cells; help body recognize foreign substances
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Membrane Proteins: Receptor Proteins
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Binds with messenger molecules; cell responds to message; ex. Divide protein synthesis channels; Diabetes- missing receptors
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Membrane Proteins: Enzymatic Proteins
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Carry out metabolic reactions
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Membrane Proteins: Junction Proteins
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Junctions between animal cells;
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Selectively Permeable
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Membrane allows certain substances to move across the membrane and not others
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Concentration Gradient
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Move from area of high concentration to low concentration
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Aquaporin
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A membrane channel protein that water moves passively through (quickly)
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Bulk transport
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Way that large particles can exit or enter a cell
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Passive transport
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No ATP required; molecules follow concentration gradient
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Active Transport
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Requires energy (ATP); requires carrier protein; low concentration gradient to high
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Diffusion
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Net movement of solute molecules down the concentration gradient (high to low) until reaches equilibrium; molecules constantly moving around
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Equilibrium
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When net change stops; solute concentration is uniform; no longer net movement, still movement
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Factors that affect rate of diffusion
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Distance, size of gradient, molecular size, temperature, electrical charge
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Osmotic pressure
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Pressure that develops in a system due to osmosis; amount of pressure that would be needed to stop osmosis across membrane
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Osmosis
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Diffusion of water across selectively permeable membrane; solvent movement not solute; high concentration draws water until equilibrium achieved
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Colligate Property
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Dependent only on number of particles
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Isotonic Solution
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Solute/water concentrations equal on both sides
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Tonicity
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Strength of the solution; ability of a solution to change shape by altering water movement
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Hypotonic Solution
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Solute concentration lower than inside cell; cells will swell as water moves into cell (lysis)
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Lysis
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Water moves into a cell and ruptures it
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Hypertonic Solution
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Solute concentration higher than inside cell; cells will shrink (crenation/plasmolysis)
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Crenation
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Red blood cell shrinks, nonfunctional (water moves out after placed in hypertonic solution
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Plasmolysis
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Shrinking of the cytoplasm of a plant cell due to osmosis; placed in hypertonic solution
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Turgor Pressure
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swelling of a plant cell in hypotonic solution; central vacuole gains water, cell wall does not give way
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Facilitated Diffusion
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Molecules combine with specific carrier protein to get across membrane; follows concentration gradient (requires no energy, high to low)
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Sodium-Potassium Pump
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carrier protein; Sodium ions are moved to the outside of the cell, potassium ions moved in; crucial for nerve cells (signaling mechanism)
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Transmembrane Potential
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Always some Na and K leaking in and out of a cell that you can't see
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Exocytosis
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Vesicles fuse with plasma membrane and secrete contents; ATP used; growth hormone, digestive enzymes, adding to/replacing parts of membrane to maintain; uses secretory pathway
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Membrane Assisted Transport
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Exocytosis and Endocytosis
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What are the three types of Endocytosis?
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Phagocytosis, Pinocytosis, Receptor-mediated
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Endocytosis
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Cells engulf substances into pouch which becomes a vesicle, energy required (bulk transport)
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Phagocytosis
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Large, solid material is moved into the vesicle, "cell-eating", foreign materials, lysosomes break down what's been brought
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Pinocytosis
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Liquid or small solid particles moved into cell; "cell drinking", plant root cells (water taken in from soil) cell swells
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Receptor Mediated Transport
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Specific form of pinocystosis using a coated pit (clathrin)- a basket like protein; coating helps recycling of vesicle to cell membrane; example (cells take up cholesterol)
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Extracellular Matrix (ECM)
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External meshwork of polysaccharides and proteins, function in strength, protection, structural support, organization, and cell signaling (Cartilage, tendons, ligaments, bones)
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Glycoaminoglycans
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Polysaccharides that attach to protein, assist in cell signaling, bind water, resist compression (fluid between bones)
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Membrane Junctions
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Junctions between animal cells; adhesion, tight, and gap
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Adhesion junctions
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Anchoring junctions, hold one cell to another, needs to be mechanically strong (stomach). Cellular adhesion molecules (CAMs)
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Tight Junctions
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Form impermeable barriers, heart, nervous system; ribbon like protein networks, prevent leakage, blood/brain barrier, intestinal cells
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Gap Junctions
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Plasma membrane channels joined; allow communication and passage of materials, electrical signals, small molecules pass through
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Plant Cell Walls
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Freely permeable cell wall, with cellulose as main component
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Plasmodesmata
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Penetrate cell walls, contains strands of cytoplasm, allows passage of materials (faster than gap junctions--> faster communication)
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Middle lamella of plant cell walls
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Cement/glue; sugary pectins; sticks cell walls together
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Metabolism
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All chemical reactions by which cells acquire and use energy
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Bioenergetics
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Analysis of how energy powers the activities of living systems
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What is the utimate source of energy for all life on Earth?
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The sun
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Kinetic Energy
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The energy of motion (mechanical, light, electrical, heat, sound, protation, wind)
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Chemical Energy
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Composed of organic molecules (carbohydrates, proteins, fat)
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Potential Energy
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Stored energy; inactive (Magnetic, gravity, chemical, elastic, nuclear)
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Energy
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The ability to do work or bring about change. Life is a constant flow of energy, all matter costantly resupplied with energy from someplace else (does not make energy)
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Which can be cycled and reused, energy or nutrients?
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Nutrients
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Does energy cycle?
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No, it flows
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First Law of Thermodynamics (Law of Conservation of Energy)
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Energy cannot be created or destroyed, but can be changed from one form to another. Total amount of energy in the universe remains the same
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Second law of Thermodynamics (Law of Entropy)
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When energy is changed from one form to antoher, there is a loss of usable energy (waste energy goes to increase disorder (entropy)
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Entropy
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The relative amount of disorganization
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If a substance is more organized and has more potential energy, is it more stable or less stable?
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Less stable (entropy)
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If a substance is less organized, is it more stable or less stable?
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More stable (entropy)
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Reactants
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Partcicipate in the reaction
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Products
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Form as a result of a reaction
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Free energy
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The amount of energy available to perform work
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Exergonic Reactions
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Products have less free energy than reactants (spontaneous; release energy)
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Endergonic Reactions
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Products have more free energy than reactants (require input of energy)
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Does spontaneous mean quick?
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No, spontaneous means the reaction happened on its own
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How are exergonic and endergonic reactions coupled?
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Energy given off by exergonic reactions is used by endergonic reactions
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ATP
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Adenosine triphosphate; high energy compound used to drive metabolic reactions and perform work; generated from ADP; adensis and ribose (adenosine) and three phosphate groups
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Is the breakdown of ATP endergonic or exergonic?
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Exergonic
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Is the synthesis of ATP exergonic or endergonic?
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Endergonic
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What are the processes that use chemical work?
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Synthesis of macromolecules, cell division
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What are the processes that use transport work?
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Pumping substances across the plasma membrane, pumping ions
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What are the processes that use mechanical work?
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Muscle contraction, myosin/actin (sliding filaments), beat flagella, nerve impulses
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Why do muscles contract at death?
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Myosin can't let go of actin with no ATP production
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Metabolic Pathway
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Series of linked reactions, products of an earlier reaction become reactants of a later reaction
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What is the first reactant in a metabolic pathway called?
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Initial reactant
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What is the last reactant in a metabolic pathway called?
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End product
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Why are there several intermediates between the starting and ending point of a metabolic pathway?
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To reduce inefficient release of heat and control the harnessing of energy
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Metabolic Turnover
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The building and breakdown of ATP, a balancing act
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What are the molecules that use ATP?
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Metabolic enzymes, transporters, motor proteins, chaperones, DNA modifying enzymes, tRN synthesases, protein kinases
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What type of reaction is the breakdown of ATP?
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Catabolic (Energy releasing reactions that harvest energy to make or transform chemical bonds; exergonic)
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What type of reaction is the synthesis of ATP?
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Anabolic (Energy required)
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Catalyst
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Speeds up the rate of a reaction, not consumed by the chemical reaction
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Enzymes
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Protein molecules that function as catalysts, each enzyme accelerates a specific reaction
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Ribozymes
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Made of RNA instead of proteins, synthesis of proteins at ribosomes
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Energy of Activation
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The energy that must be added to cause molecules to react with one another; enzymes operate by lowering the energy of activation
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How is the energy of activation lowered?
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1. Bringing substrates into contact with one another, 2. Straining (stretching) the bonds in reactants, 3. Changing the local environment of the reactants
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Active Site
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Complexes with substrate, causes active site to change shape, forces substrates together initiating bond
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Induced Fit Model
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Not lock and key, enzyme undergoes a shape change when with substrate, induced shape change to improve reaction speed
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Enzyme Degradation
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Enzyme complexes with a single substrate molecule, substrate is broken apart into two molecules (catabolic)
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Enzyme Synthesis
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Enzyme complexes with two substrate molecules, substrates are joined together and released to form a single product (dehydration synthesis, anabolic)
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What are the factors that affect enzymes?
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Enzyme concentration, substrate concentration, temperature, pH, inhibitors, and cofators
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How does enzyme concentration affect enzymes?
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The reaction rate increases as enzyme concentration increases, linear relationship when an excess of substrate is present
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How does substrate concentration affect enzymes?
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Enzyme activity increases with substrate concentration (more collisions) until point of saturation (maximum velocity=all enzyme occupied)
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How does temperature affect enzymes?
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Enzyme activity increases with temperature increase (more collisions) until too hot, then enzymes can be destroyed (denatured)
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Ectothermic
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Cannot maintain own body temperature, rely on external heat to warm enzymes
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How does pH affect enzymes?
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Most enzymes are optimized for a particular pH, changes my alter the charges and shapes of enzymes
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Phosphorylation
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Activates enzyme by adding phosphate groups
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Cofactors
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Inorganic molecules that are required to activate enzymes (ions)
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Coenzymes
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Organic molecules that are required to activate enzymes (NAD, FAD, vitamins, B12, CoA, CoQ
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Reversible enzyme inhibition
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Inhibitor is removed, enzyme activity goes back to normal
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Competitive inhibition
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Substrate and inhibitor both able to bind to active site, whichever gets there first outcompetes the other (ex. Carbon monoxide binds to hemoglobin more quickly than oxygen; HIV; bacteria)
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Noncompetitive inhibition
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Inhibitors bind not at active site, but at allosteric site
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Feedback inhibition
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End product of pathway inhibits pathway's first enzyme (*primary regulatory condition to control enzyme activity)
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Rate limiting step
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The slowest reaction in the metabolic pathway, controls the overall activity
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Irreversible Inhibition
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Permanantly shuts off enzymes, materials that permanently inhibit enzymes are known as poisons
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Cyanides
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Inhibits enzymes in ATP production
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Penicillin
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Inhibits enzymes unique to certain bacteria (kills off bacteria)
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Heavy Metals (poison)
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Irreversibly bind to many enzymes
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Nerve gas
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(Sarin) irreversibly inhibits enzymes required by nervous system
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Warfarin
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(Coumadin) Enzymes in blood clotting, towards conditions of hemophiliac
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Oxidation-Reduction Reactions
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Electrons are passed from one molecule to another (COUPLED)
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What happens to a molecule that is oxidized?
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It loses an electron
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What happens to a molecule that is reduced?
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It gains an electron (gains energy)
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Autotrophs
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Energy producers (photosynthesis)
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Heterotrophs
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Transform energy into usable form (aerobic respiration); consumers
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Photosynthesis
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Process that captures solar energy, transforms solar energy to chemical, energy stored as carbohydrates
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How much of the sun's energy directed towards the earth reaches the surface? Of this, how much is captured by photosynthesizers and how much results in biomass?
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42% reaches surface, 2% captured by photosynthesizers, small portion results in biomass
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How much of the earth's oxygen is produced by the Amazon rainforest?
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20%
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What types of organisms use photosynthesis?
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Plants, algae, cyanobacteria, some protists (diatoms)
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What is the chemical formula for photosynthesis?
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6CO2 + 12 H2O --> C6H12O6 + 6H2O + 6CO2
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Which substance is reduced in photosynthesis?
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Carbon dioxide --> C6H12O6 (glucose)
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Which substance is oxidized in photosynthesis?
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Water (donates e-) --> oxygen
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What type of reaction is photosynthesis?
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Endergonic, requires huge amounts of energy, delta G = 685 kcal/mol
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What is the relationship between wavelength and energy?
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Inverse proportions; longer wavelength = lower energy
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Photons
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Energy packets of light with both wave and particle properties
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Where does photosynthesis occur?
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The green portion of plants, the leaf of flowering plants
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Mesophyll tissue
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Where cells are specialized for photosynthesis
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Where does carbon dioxide in the air enter the leaf?
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Stomata, small openings in the leaf, cells regulate gas exchange
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Chloroplasts
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Organelles that carry on photosynthesis; carbon dioxide diffuse in, surrounded by double membrane; contains stroma and thylakoid stacks of grana
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Stroma
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Semifluid interior of chloroplasts
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Thylakoids
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Flattened sacs within the stroma of chloroplasts, stacked to form grana; individual penny like structures; UNIT OF PHOTOSYNTHESIS; where it takes place because contains chlorophyll that absorbs solar energy
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Grana
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Stacks of thylakoids in stroma of chloroplasts
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Chloropyll
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In the thylakoid membrane, absorbs solar energy that drives photosynthesis
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Phoyosynthetic Pigments
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Chemicals that absorb some wavelengths of visible light more than others; the colors that are least absorbed are reflected/transmitted the most
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Why is the dominant landscape color green?
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Chlorophyll A and B's optimum absorption is at the wavelength that produces all colors except for yellow and green; the wavelengths of light that are not being absorbed are reflected back into our eyes
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Why do leaves change to red and orange in the fall?
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Carotenoids are important in fall conditions (when temp changes, there's less daylight) so they take over; They do not absorb red and orange light, so reflected back into our eyes
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What does NADP+ changed to during photosynthesis?
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NADP+ is reduced to accept two electrons and one hydrogen atoms to form NADPH, when it is oxidized it gives up its electrons
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What supplies the electrons that reduce NADPH during photosynthesis?
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When water splits, oxygen is given off and hydrogen atoms are taken up by NADPH, later NADH reduces carbon dioxide to a carbohydrate
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When do light reactions occur?
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When light is available
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Light reactions
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Two alternate electron pathways: Noncyclic electron pathway, cyclic electron pathway; capture light energy with photosystems; occur in thylakoid membranes; both produce ATP
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Noncylic electron pathway
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Begins with PS II, captures energy from sun, splits H2O molecule, e- ejected from reaction center (chlorophyll A); replaced by electrons from splitting water moleulces of water, continue to H+ gradient
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Cyclic Electron Pathway
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Begins when PS1 complex absorbs solar energy; Start and end at the same point (cyclic); make molecules of ATP; uses only PS-1; Electron ejected from reaction center travels down electron transport chain, causes H+ to concentrate in thylakoid membranes
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PS II
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Occurs first; Captures light energy and ejects electron, splits H2O molecule, e- ejected from reaction center towards electron transport chain, replaced by electrons from splitting molecules of water (releases oxygen), continue to H+ gradient
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PS1
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Electron acceptors pass electrons to NADP+; form NADPH to be used in stroma to reduce carbon dioxide to a carbohydrate (reduces NADP+)
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What is the function of the electron transport chain in photosynthesis?
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To carry electrons from PS II to PS I; pumps H+ from stroma into thylakoid space
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ATP synthase complex
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Channel for H+ flow, drives ATP synthase to join ADP and P
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Chemiosmosis
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Harnesses energy from H+ ions, produceses ATP; establishes an H+ gradient
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What are the three stages of the Calvin Cycle of photosynthesis?
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Carbon dioxide fixation, carbon dioxide reduction, RuBP regeneration
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CO2 Fixation
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First stage of Calvin Cycle, CO2 attached to 5 carbon RuBP molecule, results in 6C molecule that splits into two 3C molecules (3PG); reaction accelerated by RuBP; CO2 now "fixed" because part of carbohydrate molecule
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Where does the Calvin Cycle take place?
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In the stroma
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What is 3PG?
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3-phosphoglycerate; first 3 carbon molecule in Calvin cycle; undergoes reduction to 3PG
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What is 3GP?
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Glyceraldehyde 3 phosphate; 3PG reduces to become 3GP in CO2 fixation
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CO2 Reduction
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Second step of Calvin cycle, Adding electrons, adding energy, 3PG reduced to 3GP; ATP becomes ADP+P and NADPH becomes NADP+ (energy and electrons needed for this reaction)
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RuBP Regeneration
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Third step of Calvin cycle; RuBP must be replaced; Carbon is recyled (never disappears); three turns of calvin cycle to allow one G3P to exit; 10 G3P molecules used to make 6 RuBP
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RuBP
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protein that makes up 20-50% of protein content in chloroplasts, enzyme that speeds up carbon dioxide fixation
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What are the molecules that can be made from G3P? (Importance of Calvin cycle)
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Sucrose, Starch (storage glucose), Cellulose (Structural carbohydrate for cell walls)
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Photorespiration
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When climate is hot and dry, stomata close to avoid wilting, O2 increases CO2 decreases, O2 starts combining with RuBP instead of CO2, photosynthesis is run in reverse (producing CO2 using O2)
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What is the enzyme used by C4 plants?
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PEP carboxylase (phophoenal pyruvate)
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C4 plants
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Thrive in hot weather; fix CO2 to PEP; avoid photorespiration; net productivity 2-3 times C3 plants; can't compete in cool moist conditions
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What is the difference in chloroplast distribution in C3 plants and C4 plants?
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In c3 plants, chloroplasts only in mesophyll; in C4 plants, chloroplasts packing mesophyll cells and bundle sheath
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Where does CO2 fixation take place in C3 plants?
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Mesophyll cells
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Where does CO2 fixation take place in C4 plants?
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Bundle sheath cells
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What is the result of adding CO2 to PEP molecules in C4 plants?
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Oxaloacetate (pumped into bundle sheath to enter Calvin cycle)
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What does CAM photosynthesis stand for?
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Crassulacean acid metabolism
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CAM photosynthesis
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Carbon dioxide fixation at night (keep stomata open, forms C4 molecules, stored in large vacuoles) During the Day: Stomata closed for water conservation, NADPH and ATP avaiable, C4 molecules release CO2 to calvin cycle
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By what do CAM plants partition carbon fixation?
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Time
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By what do C4 plants partition carbon dioxide fixation?
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Space
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What are some types of CAM plants?
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Cactus, Pineapple, jade plants, ice plants
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What are some types of C4 plants?
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Corn, sugarcane, crabgrass
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What are C4 plants most adapted to?
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High light intensities, high temperature, limited rainfall
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What are C3 plants most adapted to?
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Cold (below 25 degrees C); high moisture
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What are CAM plants most adapted to?
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Extreme aridity (desert)
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Cellular Respiration
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Cellular process that requires oxygen and gives off CO2; breakdown of glucose to CO2 and water; Energy extracted from glucose released step wise, allows ATP to be produced efficiently
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What type of reaction is cellular respiration?
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Oxidation-reduction; exergonic (delta G -686 kcal/mol); formation of products is favored (spontaneous)
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What are the four stages of cellular respiration?
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Glycolysis, transition reaction, Citric acid cycle, Electron Transport system
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In cellular respiration, which molecule is oxidized?
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C6H12O6 --> 6CO2
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In cellular respiration, which molecule is reduced?
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6O2 --> 6 H2O
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What are the products of cellular respiration?
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6CO2, 6H2O, energy and heat
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What are the coenzymes of cellular respiration?
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NAD+ and FAD
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NAD+
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Coenzyme of redox reactions, oxidizes a metabolite by accepting e-, reduces metabolite by giving up e-, each used over and over again; accepts two electrons and H+ ion to become NADH (energy storage)
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FAD
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Coenzyme of redox reactions, sometimes used instead of NAD+, accepts 2 e- and 2 H+ to become FADH2, temporarily holds energy
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Where does glycolysis occur?
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In the cytoplasm
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What are the two steps of glycolysis?
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Energy investment steps; energy harvesting steps
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What type of reaction is glycolysis?
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Anaerobic
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Glycolysis
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Energy Investment: 2 ATP used to activate glucose, glucose splits into 2 G3P molecules; Energy Harvesting: Two electrons (H atoms) are picked up by two NAD+, 4 ATP produced by substrate level phosphorylation, Net gain 2 ATP, both G3Ps converted to pyruvates
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Sugar cleavage
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Second step of glycolysis, fructose diphosphate into two G3Ps
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What controls glycolysis?
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Feedback inhibition (If sufficient ATP, bonds to phosphofructokinase (PFK))
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PFK
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Phosphofructokinase
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What happens during the energy investment step of glycolysis?
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Two ATP are used to activate glucose, splits into two G3P
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What happens in the energy harvesting step of glycolysis?
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Two elecrons (as H) are picked up by two NAD+, four ATP produced by substrate level phosphorylation, net gain of 2 ATP, both G3Ps converted to pyruvates
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Substrate level phosphorylation
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Enzyme passes a high energy phosphate to ADP, ATP results (during energy harvesting of glycolysis)
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What are the inputs of glycolysis?
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Glucose, 2 NAD +, 2 ATP, 4 ADP +4P
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What are the outputs of glycolysis?
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2 pyruvate, 2 NADH, 2 ADP, 4 ATP total (2 ATP net gain)
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Where do the prepatory reaction, citric acid cycle, and electron transport chain take place?
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mitochondria
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In which part of the mitochondria does citric acid cycle and prep reaction take place?
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In the matrix
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In which part of the mitochondria does the ETC take place?
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Cristae
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The Prepartory Reaction
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Before the citric acid cycle, pyruvate enters matrix, converted to 2C acetyl group, attaches to coenzyme A to form Acetyl CoA, electron picked up by NAD+, Co2 released and transported out of mitochondria into cytoplasm
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What are the inputs and outputs of the prepatory reaction?
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Inputs: 2 pyruvate, 2 CoA; outputs: 2 acetyl-CoA and 2 CO2
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How many times do glycolysis and the prepatory reaction run for every glucose molecule?
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Twice (carbon never disappears)
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What are the inputs and outputs of the Citric acid cycle?
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Inputs: 2 acetyl groups, 6 NAD+, 2 FAD, 2 ADP+2P; Outputs: 4CO2, 6NADH, 2FADH2, 2ATP
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What is required by the citric acid cycle?
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Oxygen
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Citric Acid Cycle
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Acetyl group carried by CoA joins with C4 molecule, C6 nitrate results; oxidation occurs when electrons accepted by NAD+ (3) and FAD (1); NADH and FADH2 produced; substrated level phosphorylation (enzyme passes high energy phosphate to ADP to make ATP); 6C atoms have nowbecome CO2
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Aerobic
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Requires oxygen
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Anaerobic
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Does not require oxygen
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What is the reason oxygen is needed in cellular respiration?
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Final acceptor of electrons from ETC, after receiving electrons oxygen combines with H to make H2O; if oxygen not present, chain does not function, no ATP produced
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Electron Transport Chain
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The process by which ATP is formed as a result of the transfer of electrons from NADH+H+ or FADH2 to O2 by a series of electron carriers
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Cytochromes
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Respiratory molecules (in ETC) complex carbon rings with metal atoms in the center, give color, binds oxygen
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How much ATP is produced by NADH delivery?
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2.31 ATPs
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How much ATP is produced by FADH2 delivery?
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1.38 ATPs
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What increases the efficiency of ETC?
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Recycling of coenzymes- once NADH delivers hydrogens it returns to pick up more, if O2 not present, NADH cannot release H and is no longer recycled back to NAD+
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What is the summary of the ETC?
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0.5 H2O + 2H+ + 2e- --> H2O
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Proton Motive Force
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The basis for chemiosmosis, receives high energy e- passes them on; each reaction has a higher energy than the previous in ETC
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Chemiosmosis
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When H+ move through ATP synthase channels, synthases uses energy to drive ATP production; H+ flows down gradient to intermembrane space, enzyme ATP synthase synthesizes ATP from ADP+P; establishment of an H+ gradient
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How many hydrogen ions are required to produce 3 ATP?
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13
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What is the energy content of the reactants of cellular respiration?
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686 kcal
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What is the energy yield of cellular respiration?
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27-29 ATP; 4 from substrate level phosphorylation, 23-25 from oxidative phosphorylation
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What is the efficiency of cellular respiration?
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29%
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Oxidative Phosphorylation
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Electron Transport Chain together with the ATP synthase activity (Chemiosmosis)
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Fermentation
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When oxygen is limited, anaerobic pathway, provides rapid burst of ATP, NAD+ for glycolysis (doesn't need O2), NADH+H+ combines with pyruvate to yield NAD+; allows glycolysis to proceed faster than O2 can be obtained
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What pain is caused by fermentation?
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Cramping. NOT soreness
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What accumulates after fermentation?
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Lactic Acid
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What are products produced by fermentation?
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Yogurt, cheese, saurkraut, yeast, alcoholic beverages
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What is the efficiency of fermentation?
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2.1% vs. 29% for aerobic respiration
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Metabolic Pool
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Foods: sources of energy rich molecules; carbohydrates, fats, proteins
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Catabolism
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Breakdown of products, enter into respiratory pathways as intermediates
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Anabolism
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Building of products
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Glycogenolysis
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Breakdown of glucose in liver
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Deamination
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Excess amino acids removed (amino group becomes poisonous ammonia, becomes urea, excreted) in liver
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What poisons disrupt cellular respiration?
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Rotenose, cyanide, olligomycin, malachite green, DNP
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What poisons block the ETC?
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Rotenone (used to kill pest insects/fish) and cyanide (binds with Cyt C, blocks passage of e- to O2: KILLS YOU, binds to hemoglobin)
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What poisons are respiratory poisons?
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Olligomycin, malachite green (block passage of H+ through channel for ATP synthase)
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What poisons are uncouplers?
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Dinitrophenol (toxic, increase metabolic rate, rapid weight loss, mitochondrial membrane leaky to H+, ETS continues but ATP can't be made)
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