Chapter 1
Cellular Biology
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Prokaryotes vs. Eukaryotes
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Prokaryotes
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Nucleus (single, circular chromosome)
Cyanobacteria, bacteria, and rickettsiae
Eukaryotes
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Complex cellular organization
Membrane-bound organelles
Well-defined nucleus
Higher animals, plants, fungi, and protozoa
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Cellular Functions
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Movement
Conductivity
Metabolic absorption
Secretion
Excretion
Respiration
Communication
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Eukaryotic Cell
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Nucleus
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Nuclear envelope
 Nucleolus
 DNA
• DNA replication, repair, and transcription
 Histone proteins
 Cell division
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Eukaryotic Cell
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Cytoplasm
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Cytoplasmic matrix
Cytosol
Function
Cytoplasmic organelles
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Eukaryotic Organelles
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Ribosomes
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RNA protein complexes
Free ribosomes
Attached ribosomes
Endoplasmic reticulum
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Site of protein synthesis
Smooth vs. rough endoplasmic reticulum
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Eukaryotic Organelles
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Golgi complex
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Flattened, smooth membranes
Secretory vesicles
Proteins from the endoplasmic reticulum are
packaged in the Golgi complex
Cisternae
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Eukaryotic Organelles
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Lysosomes
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Originate from the Golgi
Hydrolases, lipids, nucleic acids, and carbohydrates
Role in autodigestion
Peroxisomes
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Contain oxidative enzymes
Break down substances into harmless products
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Eukaryotic Organelles
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Mitochondria
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Surrounded by a double membrane
Participate in oxidative phosphorylation
Increased inner membrane surface area provided by
cristae
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Eukaryotic Organelles
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Cytoskeleton
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“Bones and muscles” of the cell
Maintains the cell’s shape and internal organization
Permits movement of substances within the cell and
movement of external projections
Microtubules
• Centrioles
Microfilaments
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Plasma Membrane
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Controls the composition of a space or
compartment they enclose
Structure
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Caveolae
Lipid bilayer
• Amphipathic lipids
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Hydrophilic and hydrophobic
• Phospholipids, glycolipids, and cholesterol
 Carbohydrates
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Plasma Membrane
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Proteins
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Integral, peripheral, transmembrane
Functions
• Receptors
• Transport
• Enzymes
• Surface markers
• Adhesion molecules
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Proteolytic Cascades
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Caspase-mediated apoptosis
Blood coagulation cascade
Matrix metalloproteinase cascade
Complement cascade
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Cell-to-Cell Adhesions
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Extracellular matrix
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Production
• Fibroblasts
Collagen
Elastin
Fibronectin
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Cell-to-Cell Adhesions
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Cell junctions
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Desmosomes
Tight junctions
Gap junctions
Gating
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Cellular Communication
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Direct linkup
Gap junctions
Hormonal signaling
Neurohormonal signaling
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Paracrine
Autocrine
Neurotransmitters
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Signal Transduction
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Extracellular first messengers
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Convey instructions to the cell’s interior
• Transfer, amplify, distribute, and modulate
Channel regulation
Second messengers
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Two pathways
• Cyclic adenosine monophosphate (cAMP)
• Ca++
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Cellular Metabolism
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Metabolism
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Chemical tasks of maintaining essential cellular
functions
Anabolism
• Energy using
Catabolism
• Energy releasing
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Adenosine Triphosphate
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Created from the chemical energy contained
within organic molecules
Used in synthesis of organic molecules,
muscle contraction, and active transport
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Cellular Energy
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Digestion
Glycolysis
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Citric acid cycle
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Occurs in the cytoplasm
Anaerobic vs. aerobic
Also called Krebs cycle or the tricarboxylic acid
cycle (TCA)
Oxidative phosphorylation
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Occurs in the mitochondria
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Membrane Transport
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Gradient
Passive transport
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Diffusion
Passive mediated transport
Filtration
Osmosis
• Osmolarity vs. osmolality
Tonicity
• Isotonic, hypertonic, and hypotonic
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Membrane Transport
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Active transport
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Protein mediated
Active transport pumps
Transport by vesicle formation
• Endocytosis
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Pinocytosis
Phagocytosis
Potocytosis
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Electrical Impulses
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Resting membrane potential
Action potential
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Depolarization
Threshold potential
Repolarization
Refractory period
• Absolute and relative
Hypopolarization and hyperpolarization
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The Cell Cycle
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Mitosis vs. cytokinesis
Chromatin vs. chromosomes
Interphase
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G1 phase
S phase
G2 phase
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The Cell Cycle
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Prophase
Metaphase
Anaphase
Telophase
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Influences on the Cell Cycle
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Cellular division rates
Growth factors
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Cytokines
Platelet derived
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Tissue Formation
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Founder cells
Chemotaxis
Contact guidance
Cellular reproduction
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Types of Tissue
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Epithelial tissue
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Simple vs. stratified
 Squamous
 Cuboidal
 Columnar
 Pseudostratified
 Structures
• Cilia and microvilli
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Types of Tissue
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Connective tissue
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Ground substance
Fibers
Loose and dense connective tissue
Elastic and reticular connective tissue
Cartilage, bone, vascular, adipose, organs
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Types of Tissue
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Muscle tissue
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Smooth
Striated (skeletal)
Cardiac
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Types of Tissue
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Neural tissue
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Neurons
Synapses
Axons
Dendrites
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