copyright © 2009 pearson education, inc. chapter 3 structure and function of cells metabolism ...
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Copyright © 2009 Pearson Education, Inc.
Chapter 3
Structure and Function of Cells
Metabolism Anabolism
Catabolism
Cell respiration Aerobic
Anaerobic
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Cells Are Classified by Internal Organization
Eukaryotes have Plasma membrane
Nucleus: information center
Cytoplasm: fluid within membrane
Organelles: structures with specialized functions
Prokaryotes have No nucleus
No true organelles
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Cell Structure Reflects Cell Function
Muscle cells Contain numerous organelles providing
energy needed for muscle contraction
Nerve cells Long and thin to carry impulses over
distance
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The Plasma Membrane
Figure 3.5
Extracellular environment
Carbohydrategroups
Cholesterol
Receptorprotein Gated channel
protein (closedposition)
Channel protein(always open)
Cytoplasm
Cytoskeletonfilaments
Phospholipid Lipidbilayer
GlycoproteinTransportprotein
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Structural Features of the Plasma Membrane
Lipid bilayer Phospholipids: polar head and nonpolar tail
Cholesterol: makes membrane a bit more rigid
Proteins: provide means of transportation through membrane
Carbohydrates: recognition patterns for cells and organisms
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Diffusion: Passive Transport Through Membrane
Passive transport No energy
required
Diffusion Movement from
area of high concentration to low
Figure 3.6
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Osmosis: Diffusion of Water
Osmosis: net diffusion of water across a semipermeable membrane
Figure 3.7
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Variations in Tonicity
Isotonic Extracellular and intracellular ionic
concentration equal
Hypotonic Extracellular ionic concentration less than
intracellular
Hypertonic Extracellular ionic concentration more than
intracellular
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Tonicity
Figure 3.13a
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Internal Structures of an Animal Cell
Figure 3.14
NucleusInformationcenter for thecell. ContainsDNA
MitochondrionProduces energyfor the cell
LysosomeDigests damaged organellesand cellular debris
RibosomesSite of protein synthesis
Secretory vesicleMembrane-boundshipping container
Golgi apparatusRefines, packages, andships macromolecular products
Rough endoplas-mic reticulumPrimary site of proteinsynthesis by ribosomes
Smooth endoplas-mic reticulumPrimary site ofmacromoleculesynthesis other thanproteins
CytoskeletonStructural frameworkof the cell
CentriolesMicrotubular structuresinvolved in cell division
PeroxisomeDestroys cellular toxic waste
CytosolSemifluid gel materialinside the cell
Plasma membraneControls movement ofmaterials into and out of cell
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Endoplasmic Reticulum (ER) and Ribosomes
Figure 3.16
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Golgi Apparatus
Receives substances from ER, refines and packages them
Figure 3.17 (1 of 2)
Golgi apparatus
Plasmamembrane
Smooth ER
Vesicle
Secretory vesicle
Lysosome
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Vesicles Ship and Store Cellular Products
Vesicles Ship and store
cellular products
Secretory membrane-bound spheres
Examples: secretory, endocytic, peroxisomes, lysosomes
Figure 3.18
Peroxisome
Lysosome
Golgi apparatus Cell toxic
waste
Bacterium
Plasma membrane
Residualbody
Harmlesswaste
Alcohol
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Mitochondria: Provide Energy to the Cell
Double membrane Inner
membrane contains enzymes that break down foods
Liberated energy is used to create ATP
Figure 3.19a
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Energy Storage
Fat Triglycerides
Long-term energy storage in animals
Glycogen Carbohydrate storage
Short-term energy storage in animals
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Cytoskeleton Supports the Cell
Microtubules
Microfilaments
Figure 3.20
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Cell Structures for Support and Movement: Cilia, Flagella, Centrioles
Cilia and flagella Used in
movement
9 + 2 microtubule arrangement
Centrioles Used in cell
division
Figure 3.20
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Cells Use and Transform Matter and Energy: Two Basic Metabolic Pathways
Anabolism Requires enzymes
Making/assembling large molecules
May require energy (ATP)
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Cells Use and Transform Matter and Energy: Two Basic Metabolic Pathways
Catabolism Requires enzymes
Breakdown of molecules
May release energy
Used in breaking down nutrients and recycling cell components
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Cellular Respiration: Cells Use Glucose and Oxygen to Supply ATP
Glucose provides energy for the cell
Figure 3.23
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Stages of Cellular Respiration
Glycolysis: in cytoplasm Splits glucose
Produces two ATP and two pyruvate molecules
Citric acid cycle: in mitochondria Also called the Krebs cycle
Extracts high-energy electrons
Produces two ATP and carbon dioxide
Electron transport system: in mitochondria Energy from electrons is used to produce ATP
Produces water and carbon dioxide
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Cellular Respiration: Overview
Figure 3.29a
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The Preparatory Step
Figure 3.26
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Fats and Proteins: Additional Energy Sources
Figure 3.30
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Fats and Proteins: Additional Energy Sources
Fats Triglycerides have twice the energy of
carbohydrates
Proteins Same energy as carbohydrates
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Anaerobic Pathways: Energy Extraction Without Oxygen
Figure 3.31
Glucose
Pyruvate Lactic acidbuildup
(2)
Mitochondrion
Mitochondrialmetabolismblocked withoutoxygen
(Glycolysis) ATP