Chapter 4 Cell Structure and Function Flashcards
Central Vacuole
A large, fluid-filled vacuole occupuying most of the volume of many plant cells; performs several functions, including maintaining turgor pressure.
Chloroplast
The organelle in plants and photosynthetic protists that is the site of photosynthesis; surrounded by a double membrane and containing an extensive inernal membrane system that bears chlorophyll.
Chromatin
The complex of DNA and proteins that makes up eukaryotic chromosones.
Chromosone
A DNA double helix together with proteins that help to organize the DNA.
Cilia
A short, hairlike projection from the surface of certain eukaryotic cells that contains microtubules in 9 + 2 arrangement. The movement of cilia may propel cells through a fluid medium or move fluids over a stationary surface layer of cells.
Cytoplasm
The material contained within the plasma membrane of a cell, exclusive of the nucleus.
Cytoskeleon
A network of protein fibers in the cytoplasm that gives shape to a cell, holds and moves organelles, and is typically involved in cell movment.
Electron Micrograph
A photographic image of an object viewed through an electron microscope.
Eukaryotic Cell
Referring to cells of organisms of the domain Eukarya (plants, animals, fungi, and protists.) Eukaryotic cells have genetic material enclosed within a membrane-bound nucleus and contain other membrane-bound organelles.
Flagella
A long, hairlike extension of the plasma membrane; in eukayotic cells, it contains microtubules arranged in a 9 + 2 pattern. The movement of flagella propel some cells through fluids.
Golgi Apparatus
A stack of membranous sacs, found in most eukaryotic cells, that is the site of processing and seperation of membrane components and secretory materials.
Lysosome
A membrane-bound organelle containing intracellular digestive enzymes.
Microtubule
A hollow, cylindrical strand, found in eukaryotic cells, that is composed of the protein tubulin; part of the cytoskeleton used in the movement of organelles, cell growth, and the construction of cilia and flagella.
Mitochondrion
An organelle bounded by two membranes, that is the site of the reactions of aerobic metabolism.
Nuclear Envelope
The double-membrane system surrounding the nucleus of eukaryotic cells; the outer membrane is typically continuous with the endoplasmic reticulum.
Nucleoid
The location of the genetic material in prokaryotic cells; not membrane-enclosed.
Nucleolus
The region of the eukaryotic nucleus that is engaged in ribosome synthesis; consists of the genes encoding ribosomal RNA, newly synthesized ribosomal RNA, and ribosomal proteins.
Nucleus
(1) atomic nucleus: the central region of an atom, consisting of proton and neutrons; (2) cellular nucleus: the membrane-bound organelle of eukaryoitc cells that contains the cell’s genetic material.
Organelle
A structure, found in the cytoplasm of eukaryotic cells that performs a specific function; sometimes refers specifically to membrane bound structures, such as the nucleus or endoplasmic reticulum.
Prokaryotic Cell
Cells of the domains Bacteria and Archaaea. Prokaryotic cells have genetic material that is not enclosed in a membrane bound nucleus; they lack other membrane-bound organelles.
Ribosome
An organelle consisting of two subunits, each composed of ribosomal RNA and protein; the bases of messenger RNA is translated into the sequence of amino acids in a protein.
Rough Endoplasmic Reticulum
Endoplasmic reticulum lined on the outside with ribosomes.
Smooth Endoplasmic Reticulum
Endoplasmic reticulum without ribosomes.
