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154 Cards in this Set
- Front
- Back
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The __ is the basic structural and functional unit of life
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Cell
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Depends on individual and collective activity of cells
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Organisms
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Activities of cells are dictated by subcellular structure- organelle
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Biochemical
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___ of life has a cellular basis
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Continuity
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Separates intracellular fluids from extracellular fluids
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Plasma membrane
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Plays a dynamic role in cellular activity
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Plasma membrane
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____ is a glycoprotein area abutting the cell that provides highly specific biological markers by which cells recognize one another
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Glycocalyx
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Double bilayer of lipids with imbedded, dispersed proteins
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Fluid Mosaic Model
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Bilayer consists of phospholipids, cholesterol, and glycolipids.
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Fluid Mosaic Model
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____ are lipids with bound carbohydrate
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Glycolipids
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_____ have hydrophobic and hydrophilic bipoles
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Phospholipids
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Plasma Membrane Surfaces differ in the kind and amount of ___ they contain.
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Lipids
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___ are found only in the outer membrane surface.
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Glycolipids
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20% of all membrane lipid is ____
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Cholesterol
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_____ are carbohydrate-attached lipids. Their role is to provide energy and also serve as markers for cellular recognition.
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Glycolipids
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____ ____ make up 20% of the outer membrane surface
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Lipid Rafts
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___ ___ are composed of sphingolipids and cholesterol
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Lipid Rafts
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___ ___ are concentrating platforms for cell-signaling molecules for ex: for B-cell and T cell response when an antigen is incountered.
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Lipid Rafts
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Impermeable juntion that encircles the cell--the closely associeated areas of two cells whose membranes join together forming a virtual impermeable membrane
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Tight Junction
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Cell adhesion proteins anchoring junction scattered along the sides of cells; ___ function like rivets.
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Desmosomes
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A nexus--a junction between certain animal cell types that allows different molecules and ions, mostly small intracellular signaling molecules to pass freely between cells.
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Gap Junctions
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- nonpolar and lipid-soluble substances
* Diffuse directly through the lipid bilayer * Diffuse through channel proteins |
Simple Diffusion
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___ ___
* Transport of glucose, amino acids, and ions * Transported substances bind carrier proteins or pass through protein channels. |
Facilitated Diffusion
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___ ____
* Are integral transmembrane proteins * Show specificity for certain polar molecules including sugars and amino acids. |
Carrier Proteins
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____, occurs when the concentration of a solvent is different on opposite sides of a membrane.
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Osmosis
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Diffusion of water across a semipermeable membrane
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Osmosis
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Total concentration of solute particles in a solution
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Osmolarity
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How a solution affects cell volume (watering plants)
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Tonicity
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The passage of water and solutes through a membrane by hydrostatice pressure.
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Filtration
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Pressure gradient pushes solute-containing fluid from a higher-pressure area to a lower-pressure area
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Filtration
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Solutions with the same solute concentration as that of the cytosol
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Isotonic
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Solution having greater solute concentration than that of the cytosol
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Hypertonic
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Solutions having lesser solute concentration than that of the cytosol
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Hypotonic
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Diffusion and Osmosis are both types of ____ _____ - that is, no energy is required for the molecules to move into or out of the cell.
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Passive Transport
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___ ___
* Uses ATP to move solutes across a membrane *Requires carrier proteins |
Active Transport
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___ ___- When cells must move materials in an opposite direction--against a concentration gradient. It requires energy.
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Active Transport
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TYPES OF ACTIVE TRANSPORT
- two substances are moved across a membrane in the same direction. |
Symport system
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TYPES OF ACTIVE TRANSPORT
- two substances are moved across a membrane in opposite directions |
Antiport System
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TYPES OF ACTIVE TRANSPORT
- hydrolysis of ATP phosphorylates the transport protein causing conformational change. |
Primary Active Transport
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TYPES OF ACTIVE TRANSPORT
- use of an exchange pump (such as the Na+ -K pump) indirectly to drive the transport of other solutes. |
Secondary Active Transport
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Trnsport of large particles and macromolecules across plasma membranes.
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Vesicular Trafficking
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____ moves substance from the cell interior to the extracellular space.
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Exocytosis
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_______ enables large particles and macromolecules to enter the cell.
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Endocytosis
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______- moving substances into, across, and then out of a cell.
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Transcytosis
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____ ____- moving substances from one area in the cell to another.
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Vesicular trafficking
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_____- pseudopods engulf solids and bring them into the cell's interior.
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Phagocytosis
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______ _______ ________-
the plasma membrane infolds, bringing extracellular fluid and solutes into the interior of the cell. |
Fluid-phase endocytosis
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_____ ______ _______-
Clathrin-coated pits provide the main route for endocytosis and transcytosis |
Receptor-Mediated Endocytosis
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___ ____ ____ _____-
caveolae that are platforms for a variety of signaling molecules |
Non- clathrin-coated vesicles
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Energy Source: Kinetic Energy
Ex: Movement of O2 through membrane |
Simple Diffusion
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Process:_________
Energy Source: Kinetic Energy Ex: Movement of glucose into cells. |
Facilitated Diffusion
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Process:_______
Energy Source: Kinetic Energy EX: Movement of H2O in & out of cells. |
Osmosis
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Process:________
Energy Source: Hydrostatic Pressure EX: Formation of Kidney filtrate |
Filtration
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Process:________
Energy Source: ATP EX: Movement of ions across membranes |
Active Transport of solutes
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Process:_________
Energy Source: ATP EX: Neurotransmitter secretion |
Exocytosis
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Process:________
Energy Source: ATP EX: White Blood Cell Phagocytosis |
Endocytosis
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Process:__________
Energy Source: ATP EX: Absorption by intestinal cells |
Fluid-phase endocytosis
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Process:________
Energy Source: ATP EX: Hormone and cholesterol uptake. |
Receptor-Mediated endocytosis
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Voltage across a membrane
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Membrane Potential
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___ ____ ____- the point where K+ potential is balanced by the membrane potential.
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Resting Membrane Potential
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Ranges from -20 to -200 mV
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Membrane Potential
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___ ____- potential maintained by active transport of ions.
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Steady State
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____ ____ ____-
*Anchor cells to the extracellular matrix *Assist in movement of cells past one another *Rally protective white blood cells to injured or infected areas *Regulate cell to cell interaction |
Cell Adhesion Molecules (CAMs)
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Important in normal development and immunity-growth
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Contact Signaling
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Voltage-regulated "ion gates" in nerve and muscle tissue.
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Electrical Signaling
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Neurotransmitters bind to chemically gated channel-linked receptors in nerve and muscle tissue.
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Chemical Signaling
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Ligands bind to a receptor which activates a G protein, causing the release of a second messenger, such as cyclic AMP.
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G protein-linked receptors
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Operation of a ___ ____,
* An extracellular ligand (first messenger), binds to a specific plasma membrane protein * The receptor activates a __ ____ that relays the message to an effector protein. |
Operation of a G Protein
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Operation of a ___ _____,
The effector is an enzyme that produces a second messenger inside the cell. *The second messenger activates a kinase *The activated kinase can trigger a variety of cellular responses. |
Operation of a G protein
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____- material between plasma membrane and the nucleus- ___ is a collective term for the cytosol plus the organelles suspended w/in the cytosol.
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Cytoplasm
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___- largely water with dissolved protein, salts, sugars, and other solutes- ____ consists mostly of water, dissolved ions, small molecules (such as protein). It contains about 20% to 30% protein.
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Cytosol
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Metabolic machinery of the cell.
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Cytoplasmic Organelles
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Chemical substances such as glycosomes, glycogen granules, and pigment.
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Inclusions
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____ _____
*Specialized cellular compartments |
Cytoplasmic Organelles
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Mitochondria, peroxisomes, lysosomes, ER, and Golgi Apparatus.
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Membranous Cytoplasmic Organelles
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Cytoskeleton, centrioles, and ribosomes
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Nonmembranous Cytoplasmic Organelles
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____-
*Double membrane structure with shelf-like cristae |
Mitochondria
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______- provides most of the cell's ATP via aerobic cellular respiration.
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Mitochondria
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______- contains its own DNA and RNA. Powerhouse of the cell.
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Mitochondria
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____- Granules containing protein and rRNA
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Ribosomes
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______- site of protein synthesis.
* free ___ synthesize souble proteins. * Membrane-bound ribosomes synthesize proteins to be incorporated into membranes. |
Ribosomes
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* Interconnected tubes and parallel membranes enclosing cisternae.
* Continuous with the nuclear membrane |
Endoplasmic Reticulum
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* External surface studded with ribosomes
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Rough ER
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* Manufactures all secreted proteins
* Responsible for the synthesis of integral membrane proteins and phospholipids for cell membranes. |
Rough ER
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* Tubules arranged in a looping network
* Catalyzes the following reactions in various organs of the body. * In the liver- lipid and cholesterol metabolism breakdown of glycogen and, along with the kidneys, detoxification of drugs. |
Smooth ER
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* Catalyzes the following reactions in various orgons of the body
* In the intestinal cells - absorbtion, synthesis, and transport of fats * In skeletal and cardiac muscle - storage and release of calcium. |
Smooth ER
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*Stacked and flattened membranous sacs
* Functions in modifications, concentration, and packaging of proteins. * Transport vessels from the ER fuse with the cis face of the ____ ____ |
Golgi apparatus
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* Transport vessels from the ER fuse with the cis face, proteins then pass through the ___ ___ to the trans face.
* Secretory vesicles leave the trans face of the ___ stack and move to designation of the cell. |
Golgi Apparatus
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* Spherical membranous bags containg digestive enzymes.
* Digest ingested bacteria, viruses, and toxins. * Degrade nonfunctional organelles * Breakdown glycogen and release thyroid hormone. |
Lysosome
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* Breakdown nonuseful tissue
* Breakdown bone to release Ca2+ * Secretory ____ are found in white blood cells, immune cells, and melanocytes |
Lysosome
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* System of organelles that function to:
* Produce, store, and export biological molecules * Degrade potentially harmful substances * Systems includes: * Nuclear envelope, smooth and rough ER, lysosomes, vacuoles, transport vesicles, Golgi apparatus, and the plasma membrane. |
Endomembrane System
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* Membranous sacs containing oxidases and catalases
* Detoxify harmful or toxic substances * Neutralize dangerous free radicals |
Peroxisomes
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____ ____- highly reactive chemicals with unpaired electrons
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Free Radicals
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* The skeleton of the cell
* Dynamic, elaborate series of rods running through the cytosol * Consists of microtubules, microfilaments, and intermediate filaments |
Cytoskeleton
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* Dynamic, hollow tubes made of the spherical protein tubulin
* Determine the overall shape of the cell and distribution of organelles |
Microtubules
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* Dynamic strands of the protein actin
* Attached to the cytoplamsic side of the plasma membrane * Baces and strengthens the cell surface. * Attach to CAMs and funtion in endocytosis and exocytosis. |
Microfilaments
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* Tough, insoluable protein fibers with high tensile strength
* Resist pulling forces on the cell and help form desmosomes- a cell structure specialized for cell-to-cell adhesion |
Intermediate Filaments
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* Protein complexes that function in motility-cells "stagger" like humans as they carry their loads of vesicles or organelles through the cell.
* Powered by ATP * Attach to receptors on organelles |
Motor Molecules
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* Small barrel-shaped organelles locaated in the centrosome near the nucleus
* Pinwheel array of nine triplets of microtubules * Organize mitotic spindle during mitosis * Form the bases of Cilia and Flagella |
Centrioles
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* Whip-like, mitile cellular extensions on exposed surfaces of certain cells
* Move substances in one direction across cell surfaces |
Cilia
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* Contains nuclear envelope, nucleoli, chromatin, and distinct compartments rich in specific protein sets
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Nucleus
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Gene-containing control center of the cell
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Nucleus
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Contains the genteic library with blueprints for nearly all cellular proteins
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Nucleus
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Dictates the kinds and amounts of proteins to be sythesized
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Nucleus
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* Selectively permeable double membrane barrier containing pores
* Encloses jellylike nucleoplasm, which contains essential solutes-substances such as nucleotides (necessary for purposes such as the replication of DNA) and enzymes ( which direct activitieis that take place in the nucleus) are dissoved in the nucleoplasm. |
Nuclear Envelope
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* Outer membrane is continuous with the rough ER and is studded with ribosomes
* Inner membrane is lined with the nuclear lamina, which maintains the shape of the nucleus. * Pore complex regulates transport of large molecules into and out of the nucleus. |
Nuclear Envelope
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* Dark-staining spherical bodies w/in the nucleus
* Site of ribosome prodution, RNA |
Nucleoli
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* Threadlike strands of DNA and histones.
* Arrangd in fundamental units called nucleosomes * Form condensed, barlike bodies of chromosomes when the nucleus starts to divide. |
Chromatin
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_____-
*Growth (G1) Synthesis (S) Growth (G2) |
Interphase
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* Mitosis and Cytokinesis |
Mitotic Phase
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___ - metabolic activity and vigorous growth
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G1
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___- cells that permanently cease dividing
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G0
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DNA replication
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S (synthetic)
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____- preparation for division
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G2
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* DNA helices begin unwinding from the nucleosomes
* Helicase untwists the double helix and exposes complemenary strands * The site of replication is the replication bubble * Each nucleotide strand serves as a template for building a new complementary strand. |
DNA Replication
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* The replisome uses RNA primers to begin DNA synthesis
* DNA polymerase III continues from the primer and covalently adds complementary nucleotides to the template. |
DNA Replication
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* Since DNA polymerase only works in one direction:
* A continuous leading strand is synthesized * A discontiuous lagging strand is synthesized * DNA ligase splices together the short segments of the discontinuous strand * Two new telomeres are also synthesized * This process is called simiconservative replication |
DNA Replication
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* Essential for body growth and tissue repair
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Cell Division
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Nuclear Division
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Mitosis
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Division of the Cytoplasm
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Cytokinesis
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The phases of Mitosis are:
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* Prophase
* Metaphase * Anaphase * Telophase |
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* Cleavage furrow formed in late anaphase by contractile ring
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Cytokinesis
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Cytoplasm is pinched into two parts after mitisis ends
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Cytokinesis
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* Asters are seen as chromatin condenses into chromosomes
* Nucleoli disappear * Centriole pairs separate and the mitotic spindle is formed |
Early and Late Prophase
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Chromosomes cluster at the middle of the cell with their centromeres aligned at the exact center, or equator, of the cell.
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Metaphase
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This arrangement of chromosomes along a plane midway beween the poles is called the ___ plate
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Metaphase
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* Centromeres of the chromosomes split
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Anaphase
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Motor proteins in kinetochores pull chromosomes toward the poles
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Anaphase
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* New sets of chromosomes extend into chromatin
* New nuclear membrane is formed from the rough ER * Nucleoli reappear * Generally ____ completes cell division. |
Telophase and Cytokinesis
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* Surface-to-surface-volume ratio of cells
* Chemical signals sucha as growth factors and hormones * Contact Inhibition * Cylins and cyclin-dependent kinases complexes |
Control of Cell Division
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* DNA serves as master blueprint for ___ ____
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Protein Synthesis
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___ are segments of DNA carrying instructions for a polypeptide chain.
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Genes
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____- of nucleotide bases form the genetic library
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PROTEIN SYNTHESIS
Triplets |
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* Each triplet specifies coding for an ___ ___.
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Amino Acid
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_____- carries the genetic information from DNA in the nucleus to the ribosomes in the cytoplasm
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Messenger RNA
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____- Bound to amino acids base pair with the codons of mRNA at the ribosome to begin the process of protein synthesis.
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Transfer RNA
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____- A structural component of ribosomes
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Ribosomal RNA
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* Transfer of information from the sense strand of DNA to RNA
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Transcription
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____ _____-
* Loosens histones from DNA in the area to be ____ * Binds to promoter, a DNA sequence specifying the start site of RNA synthesis * Mediates the binding of RNA polymerase to promotor |
Transcription factor
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* An enzyme that oversees the synthesis of RNA
* Unwinds the DNA template * Adds complementary ribonucleoside triphosphates on the DNA template * Joins these RNA nucleotides together * Encodes a termination signal to stop transcription |
Transcription: RNA Polymerase
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* A leader sequence on mRNA attaches to the small subunit of the ribosome
* Methionine-charged initiator tRNA binds to the small subunit * The large ribosomal unit now binds to this complex forming a funtional ribosome |
Initiation of Translation
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___ codons code for amino acids according to the genetic code. (Triplet Code)
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RNA
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* DNA triplets are transcribed into mRNA codons by RNA polymerase
* Codons base pair with tRNA anitcodons at the ribosomes * Amino acids are peptide bonded at the ribosomes to form polypeptide chains * Start and stop codons are used in intitiating and ending translation |
Information Transfer from DNA to RNA
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____ ____- prevents protein-coding RNA from being translated
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Antisense RNA
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______- small RNAs that interfere with mRNAs made by certain exons.
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MicroRNA
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______- mRNAs that act as swithces regulating protein synthesis in response to environmental conditions
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Riboswitches
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Nonfunctional organelle proteins are degraded by ____.
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CYTOSOLIC PROTEIN DEGRADATION
Lysosomes |
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Ubiquitin attaches to soluble proteins and they are degraded in _____.
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CYTOSOLIC PROTEIN DEGRADATION
Proteasomes |
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Body fluids and cellular secretions
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Extracellular Materials
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The ____ ____ is the defining feature of connective tissue in animals
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Extracellular Matrix
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* All cells of the body contain the same DNA but develop into all the specialized cells of the body
* Cells in various parts of the embryo are exposed to different chemical signals that channel them into specific developmental pathways |
Developmental Aspects of Cells
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* Genes of specific cells are turned on or off (by methylation of their DNA)
* Cell specialization is determined by the kind of proteins that are made in that cell. |
Developmental Aspects of Cells
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* Development of specific and distinctive features in cells is called _____ _____
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Cell differentiation
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* Wear and tear theory attributes aging to little chemical insults and formation of free radicals that have cumulative effects throughout life.
* Genetic theory attributes aging to cessation of mitosis that is programmed into our genes. |
Cell Aging
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