Chapter 2 Flashcards
Specialized cells involved in lipid storage
Fat cells
Specialized cells involved in metabolite absorption
Cells lining the intestine
Specialized cells involved in intracellular digestion
Marcophages and neutrophils
Specialized cells involved in the synthesis and secretion of steroids
Certain cells of the adrenal gland, testis, and ovary
Synthesis and secretion of glycoproteins
Cells of the mucous glands
The synthesis and secretion of degradative enzymes
Cells of the digestive glands
Convert physical and chemical stimuli into action potentials
Neurons and sensory cells
Synthesize and secrete components of the extracellular matrix
Fibroblasts, cells of bone and cartilage
Forum adhesive and tight junctions between cells
Epithelial cells
Movement
Muscle and other contractile cells
Movement of water through these multipass transmembrane proteins
Aquaporins
Movement of substances down a concentration gradient due to the Connecticut energy of the substance no expenditure of cellular energies required continues until equilibrium is reached if on ( if unopposed)
Passive Processes
Unassisted net movement of small nonpolar substances down their concentration gradient across a selectively permeable membrane examples are (exchange of oxygen and carbon dioxide between blood and body tissues)
Simple diffusion
Movement of ions and small polar molecules down their concentration gradient assisted across a selectively permeable membrane by a transport protein
Facilitated diffusion
Movement of an ion down its concentration gradient through a protein channel (an example Na+ moves through Na+ channels into the cell)
Channel-Mediated
Movement of small polar molecule down its concentration gradient by carrier protein (an example is transport of glucose into cells by a glucose carrier)
Carrier-Mediated
Diffusion of water across a selectively permeable membrane direction is determined by relative salute concentrations continues until equilibrium is reached an example are solutes in the blood in systematic capillaries “pulls” fluid from interstitial space back into the blood
Osmosis
Movement of substances requires expenditure of cellular energy
Active processes
Transport of ions are small molecules across the membrane against a concentration gradient buys transmembrane protein pumps
Active transport
Movement of substance up it’s concentration gradient power directly by ATP (an example on calcium pumps that transport calcium out of the cell; sodium/potassium pump moves sodium out of the cell and potassium into the cell)
Primary
Movement of a substance up its concentration gradient is powered by harnessing the movement of a second substance( example sodium down its concentration gradient)
Secondary
Movement of substance up its concentration gradient in the same direction and sodium (an example is a sodium/ glucose transport)
Symport
Movement of substance up its concentration gradient in the opposite direction from sodium (an example is a sodium hydrogen transport)
Antiport
Vesicle formed or lost as material is brought into a cell are released from a cell
Vesicular Transport
Bulk movement of a substance out of the cell by fusion of secretory vesicles with the plasma membrane (an example is release of a neurotransmitter by nerve cells)
Exocytosis
Bulk movement of substances into the cell by vesicles forming at the plasma membrane
Endocytosis
Type of endocytosis and which vesicles are formed as particulate materials external to the sale are engulfed by pseudopodia (an example are white blood cells engulfing a bacterium)
Phagocytosis
Type of Endocytosis in which vesicles are formed as interstital fluid is taken up by the cell (an example is formation of small vesicles in the capillary wall to move substances)
Pinocytosis
Type of Endocytosis in which plasma membrane receptors first bind specific substances; receptor and bound substance then taken up by the cell ( an example is the uptake of cholesterol into cells)
Receptor Mediated Endocytosis
The signal molecules are carried in the blood to target cells
Endocrine signaling
The chemical mediators are rapidly metabolized after release so that they act only on local cells very close to the source
Paracrine signaling
A special kind of paracrine interaction, neurotransmitters act only on adjacent cells act only on adjacent cells through special contact areas called synapses
Synaptic signaling
Signals bind receptors on the same cell type that produced the messenger molecule
Autocrine signaling
Important in early embryonic tissue interactions, signaling molecules such as proteins remain part of a cell membrane and bind surface receptors of the target cell when two cells make direct physical contact
Juxtacrine signaling
Open upon ligand binding to allow ion transfer across the membrane
Channel-linked Receptors
Ligand binding induces catalytic activity in associated peripheral proteins
Enzymatic receptors
Ligand binding change an associated “ G Protein” that binds the guanine nucleotide GTP and is released to activate other cytoplasmic proteins
G-Protein-Coupled receptors
The subunit of microtubules
Heterodimers of (alpha) & (beta) tubulin
Microtubules are located …..
Radiating in the cytoplasm from concentration at centrosomes; axonemes
The key functions of microtubules
Maintain cell’s shape and polarity; provide tracks for organelle and chromosome movement; move cilia and flagella
Subunit of microfilaments
G-actin monomers
General locations of microfilaments
Concentrated beneath cell membrane; in cell extensions like microvilli
Key functions of microfilaments
Contract and move cells; change cell shape; cytokinesis; cytoplasmic transport and streaming
Subunit of intermediate filaments
Antiparallel tetramers of 2 rod-like diners
General location of microfilaments
Arrayed throughout cytoplasm; at desmosomes; inside nuclear envelope
Key functions of intermediate filaments
Strengthen cell and tissue structure; maintain cell shape; maintain nuclear shape (lamins)
The phospholipid lipid bilayer containing cholesterol and proteins (integral and peripheral) and some carbohydrates (externally) forms a selectively permeable boundary of the cell. It acts as a physical barrier to enclose cell contents regulates material movement into and out of the cell establishes and maintains an electrical charge difference across the plasma membrane; functions in cell surface
Plasma membrane
Short numerous membrane extensions supported by microtubules which occur on exposed membrane surfaces of some cells they move substances examples are (mucus and materials) over the cell surface
Cilia
Long singular membrane extension supported by microtubules present on sperm cells it also propels Sperm cells
Flagellum
Numerous thin membrane folds projecting from the free cell surface supported by microfilaments increases membrane surface area for greater absorption
Microvilli
Large structure enclosed within a double membrane contains chromatin, nucleolus and nucleoplasm houses the DNA that serves as the genetic material for directing protein synthesis
Nucleus
Double membrane boundary between cytoplasm and nuclear contents continuous with rough ER separates nucleus from cytoplasm
Nuclear envelope
Openings through the nuclear envelope allow passage of materials between the cytoplasm and nucleoplasm including RNA protein ions and small water-soluble molecules
Nuclear Pores
Large prominent structure within the nucleus functions in synthesis of ribosomes
Nucleolus
Contents of cells between the plasma membrane and nuclear envelope responsible for many cellular processes
Cytoplasm
Viscous fluid medium with dissolved solutes (ex. ions, proteins, carbs, and lipids) provide support for organelles serves as the viscous fluid medium through which diffusion occurs
Cytosol
Membrane-bound and non membrane-bound structures carry out specific metabolic activities of the sale
Organelles
extensive interconnected membrane network bed now very’s in shape (ex. Cisternae, tubules) ribosomes attached on cytoplasmic surface modifies, transports, and stores proteins produced by attached ribosomes these proteins are secreted become components of the plasma membrane or serve as enzymes of Lysosomes
Rough ER
Extensive interconnected membrane network lacking ribosomes synthesizes, transports, and stores lipids (ex. Steroids) metabolizes carbohydrates detoxifies drugs alcohol and poisons forms vesicles and peroxisomes
Smooth E.R.
Series of several elongated flattened saclike membranous us structures modifies packages and sorts materials that arrive from the ER and transport vesicles forms secretory vesicles and lysosomes
Golgi Apparatus
Spherical shaped membrane-bound sacs; contain various types of materials to be transported through the cell transports cellular material
Vesicles
Spherical shaped membrane-bound organelles formed from the Golgi apparatus contain digestive enzymes digest microbes or materials ( ex. ingested by the cell worn out cellular components, or the entire cell)
Lysosomes
Smaller spherical shaped membrane-bound organelles formed from the ER or through fission contain oxidative enzymes detoxifies specific harmful substances either produced by the cell or taking into the cell engage in beta oxidation of fatty acids to Acetyl COA
Peroxisomes
Double membrane bound organelles containing a circular strand of DNA (genes for producing mitochondrial proteins) synthesized most ATP during aerobic cellular respiration by digestion of fuel molecules ( ex. glucose) in the presence of oxygen
Mitochondria
Organelles composed of both protein and are are in a that are organized into both a large and small subunit maybe bound to a membrane are free and cytosol engage in protein synthesis once bound can produce proteins are secreted incorporated into plasma membrane and within lysosomes free produces proteins used within the cell
Ribosomes
Organize network of protein filaments and hollowed tubules including microfilaments intermediate filaments and microtubules maintains intracellular structural support and organization of cells participates in cell division and facilitates movement
Cytoskeleton
Actin protein monomers organized into two thin intertwined protein filaments (actin filaments) maintains shape support microvilli separate two cells during cytokinesis (a process of cell division) facilitate change in cell shape participate in muscle contraction
Microfilaments
Various protein components that provide structural support stabilize junctions between cell
Intermediate filaments
Hollow cylinders composed of tubulin protein maintain cell shape and rigidity organize and move organelles support cilia and flagella participate in vascular transport separate chromosomes during the process of cell division
Microtubules
Amorphous region adjacent to the nucleus contains a pair of centrioles organizes microtubules participates in mitotic spindle formation during cell division
Centrosome
Large barrel shaped protein complexes located in both the cytosol and nucleus they degrade and digest Damaged or unneeded proteins ensure quality of exported proteins
Proteasomes
Aggregates of specific types of molecules(ex. melanin protein glycogen or lipid) serve as temporary storage for these molecules
Inclusions
