Openstax Biology - Chapter 4 - Cell Structure

Front 1

cell wall

Back 1

rigid cell covering made of cellulose that protects the cell, provides structural support, and gives shape to the cell

Front 2

central vacuole

Back 2

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

Front 3

centrosome

Back 3

region in animal cells made of two centrioles

Front 4

chlorophyll

Back 4

green pigment that captures the light energy that drives the light reactions of photosynthesis

Front 5

chloroplast

Back 5

plant cell organelle that carries out photosynthesis

Front 6

chromatin

Back 6

protein-DNA complex that serves as the building material of chromosomes

Front 7

chromosome

Back 7

structure within the nucleus that is made up of chromatin that contains DNA, the hereditary material

Front 8

cilium

Back 8

short, hair-like structure that extends from the plasma membrane in large numbers and is used to move an entire cell or move substances along the outer surface of the cell, plural = cilia

Front 9

cytoplasm

Back 9

entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals

Front 10

cytoskeleton

Back 10

network of protein fibers that collectively maintain the shape of the cell, secure some organelles in specific positions, allow cytoplasm and vesicles to move within the cell, and enable unicellular organisms to move independently

Front 11

cytosol

Back 11

gel-like material of the cytoplasm in which cell structures are suspended

Front 12

desmosome

Back 12

linkages between adjacent epithelial cells that form when cadherins in the plasma membrane attach to intermediate filaments

Front 13

electron microscope

Back 13

an instrument that magnifies an object using a beam of electrons passed and bent through a lens system to visualize a specimen

Front 14

endomembrane system

Back 14

group of organelles and membranes in eukaryotic cells that work together modifying, packaging, and transporting lipids and proteins

Front 15

endoplasmic reticulum

Back 15

series of interconnected membranous structures within eukaryotic cells that collectively modify proteins and synthesize lipids, also known as the ER

Front 16

eukaryotic cell

Back 16

cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs

Front 17

extracellular matrix

Back 17

material (primarily collagen, glycoproteins, and proteoglycans) secreted from animal cells that provides mechanical protection and anchoring for the cells in the tissue

Front 18

flagellum

Back 18

long, hair-like structure that extends from the plasma membrane and is used to move the cell, plural = flagella

Front 19

gap junction

Back 19

channel between two adjacent animal cells that allows ions, nutrients, and low molecular weight substances to pass between cells, enabling the cells to communicate

Front 20

Golgi apparatus

Back 20

eukaryotic organelle made up of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution

Front 21

intermediate filament

Back 21

cytoskeletal component, composed of several intertwined strands of fibrous protein, that bears tension, supports cell-cell junctions, and anchors cells to extracellular structures

Front 22

light microscope

Back 22

an instrument that magnifies an object using a beam visible light passed and bent through a lens system to visualize a specimen

Front 23

lysosome

Back 23

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

Front 24

microfilament

Back 24

narrowest element of the cytoskeleton system; it provides rigidity and shape to the cell and enables cellular movements

Front 25

microscope

Back 25

an instrument that magnifies an object

Front 26

microtubule

Back 26

widest element of the cytoskeleton system; 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

Front 27

mitochondria

Back 27

cellular organelles responsible for carrying out cellular respiration, resulting in the production of ATP, the cell’s main energy-carrying molecule, singular = mitochondrion

Front 28

nuclear envelope

Back 28

double-membrane structure that constitutes the outermost portion of the nucleus

Front 29

nucleoid

Back 29

central part of a prokaryotic cell in which the chromosome is found

Front 30

nucleolus

Back 30

darkly staining body within the nucleus that is responsible for assembling the subunits of the ribosomes

Front 31

nucleoplasm

Back 31

semi-solid fluid inside the nucleus that contains the chromatin and nucleolus

Front 32

nucleus

Back 32

cell organelle that houses the cell’s DNA and directs the synthesis of ribosomes and proteins

Front 33

organelle

Back 33

compartment or sac within a cell

Front 34

peroxisome

Back 34

small, round organelle that contains hydrogen peroxide, oxidizes fatty acids and amino acids, and detoxifies many poisons

Front 35

plasma membrane

Back 35

phospholipid bilayer with embedded (integral) or attached (peripheral) proteins, and separates the internal content of the cell from its surrounding environment

Front 36

plasmodesma

Back 36

channel that passes between the cell walls of adjacent plant cells, connects their cytoplasm, and allows materials to be transported from cell to cell, plural = plasmodesmata

Front 37

prokaryote

Back 37

unicellular organism that lacks a nucleus or any other membrane-bound organelle

Front 38

ribosome

Back 38

cellular structure that carries out protein synthesis

Front 39

rough endoplasmic reticulum

Back 39

region of the endoplasmic reticulum that is studded with ribosomes and engages in protein modification and phospholipid synthesis; also known as the RER

Front 40

smooth endoplasmic reticulum

Back 40

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; also known as the SER

Front 41

tight junction

Back 41

firm seal between two adjacent animal cells created by protein adherence

Front 42

unified cell theory

Back 42

a biological concept that states that all organisms are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells

Front 43

vacuole

Back 43

membrane-bound sac, somewhat larger than a vesicle, which functions in cellular storage and transport

Front 44

vesicle

Back 44

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