Membrane transport processes for which ATP is required. (Ex. solute pumping and endocytosis)
Active (transport) processes
Refers specifically to soulute pumping.
Active (transport) pumping
The flowing movement of the cytoplasm of a phagocyte.
Third stage of mitosis, meiosis Iand meiosis II in which daughter chromosomes move toward each pole of a cell.
The three-base sequence complementary to the messenger RNA (mRNA) codon.
A cell withour a nucleus.
A process of controlled cellular suicide; eliminates cells that are unneeded, stressed, or aged.
Transmembrane proteins that form water channels.
Reduction in size or wasting away of an organ or cell resulting from disease or lack of use.
Process of autodigestion (self-digestion) of cells, especially dead or degenerate cells.
An organelle structurally identical to a centriole and forming the base of a cilium or flagellum.
A transmembrane protein that changes shape to envelpo and transport a polar substance across the cell membrane.
Structural unit of all living things.
The development of specific and distinctive features in cells, from a single cell (the fertilized egg) to all the specialized cells of adulthood.
Series of changes a cell goes through from the time it is formed until it reproduces itself.
Cell life cycle
Membrane, composed of phospholipids, cholesterol, and proteins, that encloses cell contents; outer limiting cell membrane.
Cell membrane (Plasma membrane)
Minute body found near the nucleus of the cell; active in cell division.
A region near the nucleus which contains paired organelles called centrioles.
Centrosome (Cell center)
A transmembrane protein that forms an aqueous pore, allowing substances to move from one side of the membrane to the other.
Structures in the nucleus that carry the hereditary factors (genes).
Barlike bodies of tightly coiled chromatin; visible during cell division.
Tiny, hairlike projections of cell surfaces that move in a wavelike manner.
Any cavity or enclosed space serving as a resevoir.
The three-base sequence on a messenger RNA molecule that provides the genetic information used in protein synthesis; code for a given amino acid.
The difference in the concentration of a particular substacne between two different areas.
Intracellular second messenger that mediates the effects of the first (extracellular) messenger (hormone or neurotransmitter); formed from ATP by a plasma membrane enzyme (adenylate cyclase).
The division of cytoplasm that occurs after the cell nucleus has divided.
The cellular material surrounding the nucleus and enclosed by the plasma membrane.
Literally, cell skeleton. An elaborate series of rods running through the cystol, supporting cellular structures and providing the machinery to generate various cell movements.
Viscous, semitransparent fluid substance of cytoplasm in which other elements are suspended.
Cell junction composed of thickened plasma membranes joined by filaments.
Diffusion of solute(s) through a semipermeable membrane.
The spreading of particles in a gas or solution with a movement toward uniform distribution of particles; driven by kinetic energy.
Process that occurs before cell division; ensures that all daughter cells have identical genes.
The combined difference in concentration and charge; influences the distribution and direction of diffusion of ions.
Means by which fairly large extacellular molecules or particles enter cells. (Ex. phagocytosis, pinocytosis, receptor-mediated endocytosis).
Membranous network of tubular or sac-like channels in the cytoplasm of a cell.
Endoplasmic reticulum (ER)
Mechanism by which substances are moved from the cell interior to the extracellular space as a secretory vesicle fuses with the plasma membrane.
Amino acid-specifying informational sequences (seperated by introns) in the genes of higher organisms.
Passive transport process used by certain molecules, (ex. glucose and other simple sugars) too large to pass through plasma membrane pores. Involves movement through channels or movement facilitated by a membrane carrier.
Passage of a solvent and dissolved substances through a membrane or filter.
Long, whiplike cellulat extension containing microtubules; propels sperm and some single-celled eukaryotes.
A depiction of the structure of the membranes of a cell as phospholipid bilayers in which proteins are dispersed.
Fluid mosaic model
Highly reactive chemicals with unpaired electrons that can scramble the stucture of proteins, lipids, and nucleic acids.
Protein that relays signals between extracellular first messengers (hormones and neurotransmitters) and intracellular second messengers (such as cyclic AMP) via effector enzyme.
A passageway between two adjacent cells; formed by transmembrane proteins called connexons.
One of the biological units of heredity located in chromatin; transmits hereditary information.
Refers to the rules by which the base sequence of a DNA gene is translated into protein structures (amino acid sequences).
A layer of externally facing glycoproteins on a cell's plasma membrane that determines blood type; involved in the cellular interactions of fertilization, embryonic development, and immunity, and acts as an adhesive between cells.
Glycocalyx (cell coat)
A lipid with one or more covalently attached sugars.
Membranous system close to the cell nucleus that packages protein secretions for export, packages enzymes into lysomes for cellular use, and modifies proteins destined to become part of cellular membranes.
Refers to molecules, or portions of molecules, that interact with water and charged particles.
Refers to molecules, or portions of molecules, that interact with nonpolar molecules.
Accelerated growth (Ex. in anemia) the bone marrow produces red blood cells at a faster rate.
Excessive, above normal, tone or tension.
A solution that has a higher concentration of nonpenetrating solutes that the reference cell; having greater osmotic pressure than the reference solution (blood plasma or interstitial fluid).
Increase in size of a tissue or organ independent of the body's general growth.
Below normal tone or tension.
A solution that is more dilute (containing fewer nonpenetrating solutes) than the reference cell. Cells placed in hypotonic solutions plump up rapidly as water rushes into them.
One of two major periods in the cell life cycle; includes the perios from cell formation to cell division.
Fluid between the cells.
Interstitial fluid (IF)
Fluid within a cell.
Intracellular fluid (ICF)
Noncoding segment or portion of DNA that ranges from 60 to 100,000 nucleotides long.
A solution with a concentration of nonpenetrating solutes equal to that found in the reference cell.
Signaling chemicals that bind specifically to membrane receptors.
Organelles that originate from the Golgi apparatus and contain strong digestive enzymes.
Voltage across the plasma membrane.
A large, diverse group of integral proteins and glycoproteins that serve as binding sites for signaling molecules.
Long nucleotide strands that reflect the exact nucleotide sequences of genetically active DNA and carry the message of the latter.
Messenger RNA (mRNA)
Second stage of mitosis.
Thin strands of the contractile protein actin.
One of three types of rods in the cytoskeleton of a cell; hollow tubes made of spherical protein that determine tha cell shape as well as the distribution of cellular organelles.
Tiny projections on the free surfaces of some epithelial cells; increas surface area for absorption.
Cytoplasmic organelles responsible for ATP generation for cellular activities.
Process during which the chromosomes are redistributed to two daughter nuclei; nuclear division. Consists of prophase, metaphase, anaphase, and telpphase.
One of two major periods in the cell life cycle; involves the division of the nucleus (mitosis) and the division of the cytoplasm (cytokinesis).
Mitotic (M) phase
Cell with more than one nucleus (Ex. skeletal muscle, cells, osteoclasts).
Death or disintegration of a cell or tissues caused by disease or injury.
The double membrane barrier of a cell nucleus.
Dense spherical bodies in the cell nucleus involved with ribosomal RNA (rRNA) synthesis and ribosomal subunit assembly.
Fundamental unit of chromatin; consists of a strand of DNA wound around a cluster of eight histone proteins.
Control center of a cell; contains genetic material.
Clusters of nerve cell bodies in the CNS.
Small cellular structures (ribosomes, mitochondria, and others) that perform specific metabolic function for the cell as a whole.
The number of solute particles present in 1 liter of a solution.
Diffusion of a solvent through a mambrane from a dilute solution into a more concentrated one.
A measure of the tendency of water to move into a more concentrated solution.
Membrane transport processes that do not require cellular energy (ATP), (Ex. diffusion), which is driven by kinetic energy.
Passive (transport) processes
Progressive, wavelike contractions that move foodstuffs through the alimentary tube organs (or that move other substances through other hollow body organs).