APHY 101 Ch. 3 Terms Flashcards
Micrometer
A unit of measurement that equals one thousandth of a millimeter and is symbolized μm
Differentiated cells
Cells with specialized characteristics that form from less specialized cells that divide and express specific genes.
Cell’s Major Parts
- Nucleus (enclosed by the nuclear envelope)
- Cytoplasm
- Cell Membrane
Nucleus
Contain genetic material (DNA) which directs the cell’s functions
Cytoplasm
Found within the cell membrane; the protoplasm within a living cell that surrounds the nucleus.
Cytosol
The aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.
Cytosol Organelles
The cytosol and organelles together compose the cell’s cytoplasm. Most organelles are surrounded by a lipid membrane similar to the cell membrane of the cell.
Cell Membrane
Mainly composed of roughly equal numbers of lip and protein molecules, with fewer carbohydrates.
Extremely thin. Maintains cell’s integrity. Controls the entrance and exit of substances.
Selectively Permeable
A membrane that controls the entrance and sit of substances , allowing some in while excluding others.
Signal Transduction
A process in which the cell is able to receive and respond to incoming messages via the cell membrane and extracellular fluids.
Bilayer
The basic framework of the cell membrane that is a double layer of phospholipid molecules that self-assemble so that their hydrophilic, phosphate containing “heads”, form the intracellular and extracellular surfaces of the membrane while the hydrophobic, fatty acid containing “tails”, make up the middle portion of the cell membrane.
Membrane Proteins
Provide specialized functions. They are classified by shape, their positions within the phospholipid bilyarer, and function.
May be shaped like globs, rods, or fibers.
Based on position, may be considered as integral or peripheral.
Receptors
Transmembrane proteins that are tightly coiled rods. They bind to specific incoming molecules such as hormones, triggering responses from within the cell.
Integral Protein
Extends into the lipid bilayer and may protrude from one or both sides.
Form pores, channels, and carries in the cell membrane; transduce signals.
Transmembrane Protein
An integral protein that extends through both sides of the lipid bilayer.
Peripheral Protein
Associate with one side of the lipid bilayer, from an outside attachment rather than being embedded within it.
Receptor Protein
Peripheral.
Respond to extracellular signals.
Cell Surface Proteins
Establish self
Cellular Adhesion Molecules
Enable cells to stick to each other, guide cells on the move.
Selectin
A type of cellular adhesion molecule that coats the white blood cell and provides traction to slow down.
Integrin
A type of cellular adhesion molecule that contacts and adhesion receptor protein protruding into the capillary cell membrane, grabbing the passing slowed white blood cell and directing it between the tile like cells of the capillary wall.
Inclusion
Chemicals found with the cytoplasm temporarily. These include stored nutrients (ie; glycogen and lipids), and pigments (ie; melanin).
Cytoskeleton
Protein rods and tubules that form a supportive framework in the cytoplasm.
Characteristics of vesicles
- contains substances that have just entered the cell
- contain substances that have been produced by other organelles
- are membranous sacs
Cellular energy
the source of energy for active transport mechanisms
Ribosomes
- Tiny, spherical structures composed of protein and RNA
- They provide structural support and enzymatic activity to like amino acids to synthesize proteins
- Scattered in the cytoplasm and bound to the endoplasmic reticulum
Endoplasmic Reticulum
- A complex organelle composed of membranous flattened-sacs, cylinders and fluid-filled bubble like sacs called vesicles that are interconnected and interact with the cell membrane, nuclear envelope and certain other organelles.
- Widespread in the cytoplasm; providing tubular transport for molecules throughout the cell
- Parts participate in the synthesis of protein and lips molecules
Rough Endoplasmic Reticulum
- Part of the ER where the outer surface is studded with many ribosomes that provide a textured appearance to the organelle.
Smooth Endoplasmic Reticulum
- Part of the ER where the surface lacks ribosomes; it appears more cylindrical.
- Along this part of the ER are enzymes that are important in synthesizing lipids, absorbing fats from the digestive tract, and breaking down certain drugs.
- Especially abundant in liver cells to help break down alcohol and drugs
Vesicles
- Membranous sacs that store or transport substances within a cell or between cells.
- Vary in size and contents.
- Larger: contain mostly water
- Smaller: shuttle material from the rough ER to the Golgi as part of secretion
Vesicle Trafficking
The transport of substance into and out of the cells by fleets of vesicles
Golgi Apparatus
- A stack of five to eight flattened, membranous sacs called cistern (stack of pancakes).
- Refines, packages, and transports proteins synthesized in the rough ER
- Glycoproteins pass from layer to layer through these stacks and may be chemically modified and packaged to move to the cell membrane – exocytosis
Diffusion
Exchange of oxygen and carbon dioxide in the lung
Facilitated Diffusion
Movement of glucose through a cell membrane
Osmosis
Distilled water entering cell
Filtration
Water molecules leaving blood capillaries
Active Transport
Sodium potassium pump
Ribosome
Site of protein synthesis
Cytoskeleton
Three parts:
- Microfilament
- Intermediate Filaments
- Microtubule
Nucleus
Surrounded by an envelope and contains genetic material