Cell Structure (Ch. 4) Flashcards
Cell Wall
rigid cell covering comprised of various molecules that protects the cell, provides structural support, and gives shape to the cell.
central vacuole
large plant cell organelle that regulates the cell’s storage compartment, holds water, and plays a significant role in cell growth as the site of macromolecule degradation.
chloroplast
plant cell organelle that carries out photosynthesis
cilium (plural = cilia)
short, hair-like structure that extends from the plasma membrane in large numbers and functions to move an entire cell or move substances along the cell’s outer surface
cytoplasm
entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals.
cytoskeleton
protein fiber network that collectively maintains the cell’s shape, secures some organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently.
cytosol
the cytoplasm’s gel-like material in which cell structures are suspended.
eukaryotic cell
a cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs
extracellular matrix
material secreted from animal or fungal cells that provides mechanical protection and anchoring for the cells in the tissue.
flagellum (plural = flagella)
long, hair-like structure that extends from the plasma membrane and moves the cell
gap junction
channel between two adjacent animal cells that allows ions, nutrients, and low molecular weight substances to pass between cells, enabling the cells to communicate.
Golgi apparatus
eukaryotic organelle comprised of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution.
intermediate filament
cytoskeletal component, comprised of several fibrous protein intertwined strands, that bears tension, supports cell-cell junctions, and anchors cells to extracellular structures.
lysosome
organelle in an animal cell that functions as the cell’s digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles.
microfilament
the cytoskeleton system’s narrowest element; it provides rigidity and shape to the cell and enables cellular movements.
microtubule
the cytoskeleton system’s widest element; it helps the cell resist compression, provides a track along which vesicles move through the cell, pulls replicated chromosomes to opposite ends of a dividing cell, and is the structural element of centrioles, flagella, and cilia.
mitochondria (singular = mitochondrion)
cellular organelles responsible for carrying out cellular respiration, resulting in producing ATP, the cell’s main energy-carrying molecule
nuclear envelope
double-membrane structure that constitutes the nucleus’ outermost portion.
nucleolus
darkly staining body within the nucleus that is responsible for assembling ribosome subunits.
nucleoplasm
semi-solid fluid inside the nucleus that contains the chromatin and nucleolus.
nucleus
cell organelle that houses the cell’s DNA and directs ribosome and protein synthesis.
plasma membrane
phospholipid bilayer with embedded (integral) or attached (peripheral) proteins and separates the cell’s internal content from its surrounding environment.
plasmodesma (plural = plasmodesmata)
channel that passes between adjacent plant cells’ cell walls, connects their cytoplasm, and allows transporting of materials from cell to cell
prokaryote
unicellular organism that lacks a nucleus or any other membrane-bound organelle
ribosome
cellular structure that carries out protein synthesis
rough endoplasmic reticulum (RER)
region of the endoplasmic reticulum that is studded with ribosomes and engages in protein modification and phospholipid synthesis.
smooth endoplasmic reticulum (SER)
region of the endoplasmic reticulum that has few or no ribosomes on its cytoplasmic surface and synthesizes carbohydrates, lipids, and steroid hormones; detoxifies certain chemicals (like pesticides, preservatives, medications, and environmental pollutants), and stores calcium ions.
tight junction
protein adherence that creates a firm seal between two adjacent animal cells
unified cell theory
a biological concept that states that one or more cells comprise all organisms; the cell is the basic unit of life; and new cells arise from existing cells.
vesicle
small, membrane-bound sac that functions in cellular storage and transport; its membrane is capable of fusing with the plasma membrane and the membranes of the endoplasmic reticulum and Golgi apparatus.
