Structure & Function of the Body Ed 16 Patton 2023

cytoplasm the material or protoplasm within a living cell, excluding the nucleus; the living substance that exists only in cells; all the living material inside the cell (except the nucleus); fills the spaces between the plasma membrane and the nucleus plasma membrane thin membrane that surrounds each cell in the body; separates the cells contents from interstitial fluid; forms the cells outer boundary; phospholipid bilayer studded with proteins; protein and carbohydrate molecules on the outer surface serve as markers that identify cells of each individual, as receptor molecules for certain hormones, or transporters to move substances through the membrane interstitial fluid (IF) tissue fluid, which bathes every cell in the body organelles specialized structures contained within the cytoplasm of each cell; little organs; function for the cell as organs function for the body nucleus small, circular body inside the cell; large, membrane- bound structure in most cells that contains most of the cell's genetic code; double-membraned, spherical envelop containing DNA strands; contains DNA, which dictates protein synthesis, thereby playing an essential role in other cell activities such as transport, metabolism, growth, and heredity; controls every organelle in the cytoplasm and cell reproduction three main parts of a cell plasma membrane, cytoplasm, nucleus phospholipids phosphate-containing lipid molecules that form a fluid framework for the plasma membrane; stabilized by cholesterol to prevent breakage of the plasma membrane cytoskeleton cell skeleton; small threadlike structures in cytoplasm that interconnect; organizes and supports organelles; contain microfilaments and microtubules microfilaments Fine, threadlike proteins found in the cell's cytoskeleton microtubules A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella. ribosomes tiny particles, each made up of two rRNA subunits; synthesize proteins; a cell's protein factories; make enzymes endoplasmic reticulum membranous network of interconnected canals and sacs, some with ribosomes attached (rough ER) and some without attachments (smooth ER); rough ER receives (folds) and transports synthesized proteins (from ribosomes); smooth ER synthesizes lipids and certain carbohydrates; Smooth ER make lipids, carbohydrates, and proteins that make up cellular membrane material golgi apparatus stack of flattened, membranous sacs near the nucleus; chemically processes, then packages substances from the ER; vesicles (tiny sacs) fuse with the golgi sacs and allow the contents of both to mingle and release contents from the cell; the cell's chemical processing and packaging center mitochondria membranous capsules containing a large, folded internal membrane encrusted with enzymes; ATP synthesis; a cell's power plants or battery charges lysosome bubble of hydrolysis enzymes encased by membrane; a cell's digestive bag, it breaks apart large molecules; help protect cells against destruction by microbes by digesting and thereby destroying the microbes that invade the cell centrosome region of cytoplasm near nucleus without a visible boundary; contains centrioles; organizes microtubules of the cytoskeleton; important role in organizing and moving the structures within the cell centrioles pair of hollow cylinders at right angles to each other, each made up of tine tubules within the centrosome; help organize and move chromosomes during cell reproduction microvilli small, fingerlike tiny cell surface extensions supported internally by microfilaments; increase surface area of plasma membrane for efficiency of absorption cilia hair-like cell surface extensions supported by an internal cylinder made of microtubules (longer than microvilli); sensory antennae to detect conditions outside the cell; some cilia also move substances over surface of the cell flagellum long whiplike projection on the sperm; similar to a cilium but much longer; the only example in humans is the tail of a sperm cell, propelling the sperm through fluids nucleolus dense region of the nucleus; makes subunits that form ribosomes that are critical in protein formation cellular respiration Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen apoptosis cell suicide, which makes space for newer cells chromatin granules made of proteins around which are wound segments of DNA chromosomes threadlike structures made of DNA molecules that contain the genes cell extensions Cilia, Flagella and Microvilli transport processes allow mass movement of substances into and out of cells; passive and active active transport the movement of materials through a cell membrane using energy passive transport the movement of materials through a cell membrane without using energy; diffusion, dialysis, osmosis, filtration diffusion movement of particles through a membrane from an area of high concentration to an area of low concentration (concentration gradient); passive osmosis passive movement of water through a selectively permeable membrane in the presence of at least one impermeant solute; passive filtration movement of water and small solute particles, but not larger particles, through a filtration membrane; movement occurs from area of high pressure to area of low pressure; passive ion pump movement of solute particles from an area of low concentration to an area of high concentration (up the concentration gradient) by means of a carrier protein structure; active phagocytosis movement of cells or other large particles into cell by trapping it in a section of plasma membrane that pinches off inside the cell; active pinocytosis movement of fluid and dissolved molecules into a cell by trapping them in a section of plasma membrane that pinches off inside the cell; active genome all of the DNA in each cell of the body transcription (genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA (messenger RNA) messenger RNA (mRNA) form of RNA that carries genetic information from the nucleus to the cytoplasm, where it serves as a template for protein synthesis translation (genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm transfer RNA (tRNA) type of RNA molecule that transfers amino acids to ribosomes during protein synthesis cell reproduction the division of the cell into two genetically identical daughter cells; requires division of the nucleus (mitosis) and division of the cytoplasm mitosis division of the nucleus; the process of dividing the replicated genetic material (DNA) of the nucleus in an orderly way so that each resulting daughter cell has a complete identical set interphase 1) period of the cell cycle between cell divisions; cell growth, replication of chromosomes, cell not actively dividing; most of a cell's lifespan is spent in interphase prophase 2) first stage of mitosis; chromatin condenses into visible chromosomes; chromatids become attached at the centromere, spindle fibers appear; the nucleolus and nuclear envelope disappear metaphase 3) second stage of mitosis; nuclear envelope and nucleolus have disappeared; spindle fibers attach to each chromatid, chromosomes align across the center of the cell anaphase 4) third stage of mitosis; centromeres break apart, chromosomes move away from the center of the cell; the cleavage furrow appears telophase 5) the nuclear envelope and both nuclei appear; cytoplasm and organelles divide equally; the process of cell division is complete cytokinesis the division of the plasma membrane and cytoplasm surrounding the nucleus