Chapter 3: Cells Flashcards
a theory stating that all living organisms are composed of cells
cell theory
device that uses light and a series of lenses to obtain images of a specimen
light microscope
having a cell or cells that lack a distinct nucleus and other membrane-bound organelles
prokaryotic
pertaining to cells having distinct membrane-bound organelles, including a nucleus with chromosomes
eukaryotic
the theory that mitochondria and chloroplasts were free-living bacteria that became incorporated in cells
endosymbiotic theory
the relatively rigid boundary of cells of plants and certain other organisms
cell wall
a membrane-bound body in the cytoplasm of a cell; there are several kinds, each with a specific function
organelle
living part of a cell
protoplasm
the protoplasm of a cell exclusive of the nucleus
cytoplasm
What is the main structural component of cell walls?
cellulose
-cell walls also typically contain a matrix of hemicellulose, pectin, and glycoproteins
a layer of material, rich in pectin, that cements two adjacent cell walls together
-permeable and permits slower movement of water and dissolved substances between cells
middle lamella
minute strands of cytoplasm that extend between adjacent cells through pores in the walls
-the translocation of sugars, amino acids, ions, and other substances occurs here
plasmodesma (pl. plasmodesmata)
the outer boundary of the protoplasm of a cell; also called “cell membrane,” particularly in animal cells
-composed mostly of lipids
plasma membrane
a porous double membrane enclosing a nucleus
nuclear envelope
a somewhat spherical body within a nucleus; contains primarily RNA and protein; there may be more than one per nucleus
nucleolus (pl. nucleoli)
a readily staining complex of DNA and proteins found in chromosomes
chromatin
a body consisting of a linear sequence of genes and composed of DNA and proteins; found in cell nuclei and appear in contracted form during mitosis and meiosis
chromosome
a complex system of interlinked, double-membrane channels subdividing the cytoplasm of a cell into compartments; parts of it are lined with ribosomes
endoplasmic reticulum (ER)
a granular particle composed of 2 subunits consisting of RNA and proteins; lack membranes, are the sites of protein synthesis, and are very numerous in living cells
ribosome
an organelle consisting of disc-shaped, often branching hollow tubules that function in accumulating and packaging substances used in the synthesis of materials by the cell
dictyosome
an organelle associated primarily with the storage or manufacture of carbohydrates
plastid
an organelle containing chlorophyll, found in cells of most photosynthetic organisms; sites of photosynthesis
chloroplast
a series of stacked thylakoids within a chloroplast are arranged in stacks that form the grana of chloroplasts
granum (pl. grana)
coin-shaped membranes whose contents include chlorophyll; they are arranged in stacks that form the grana of chloroplasts
thylakoid
green pigments essential to photosynthesis
chlorophyll
a region constituting the bulk of the volume of a chloroplast or other plastid; it contains enzymes that in chloroplasts play a key role in carbon fixation, carbohydrate synthesis, and other photosynthetic reactions
stroma
a plastid containing pigments other than chlorophyll; the pigments are usually yellow to orange
chromoplast
a colorless plastid commonly associated with starch accumulation
-amyloplasts, elaioplasts
leucoplast
a tiny, undifferentiated organelle that can duplicate itself and that may develop into chloroplast, leucoplast, or other types of plastids
proplastid
an organelle containing enzymes that function in the citric acid cycle and the electron transport chain of aerobic respiration, which involves the production of ATP from food molecules
mitochondrion (pl. mitochondria)
a small, spherical organelle which contains special enzymes and is bounded by a single membrane
microbody
organelle that contains enzymes for breakdown of toxic substances and, in plants, participates in photorespiration
peroxisome
organelle that contains enzymes for the conversion of fats into sugars
glyoxisome
a pocket of fluid that is separated from the cytoplasm of a cell by a membrane; also, food-storage or contractile pockets within the cytoplasm of unicellular organisms
vacuole
the eliminating membrane of a cell vacuole; aka tonoplast
vacuolar membrane
the liquid contents of a vacuole
cell sap
a protein filament involved with cytoplasmic streaming and with contraction and movement in eukaryotic cells
microfilaments
a sequence of events involved in the division of a cell
cell cycle
period in which the cell is performing its intended function and not dividing
interphase
nuclear division, usually accompanied by cytokinesis, during which the chromatids of the chromosomes separate and two genetically identical daughter nuclei are produced
mitosis
division of a cell, usually following mitosis
cytokinesis
stage of mitosis or meiosis in which chromosomes become thick and visible
prophase
one of the two strands of a chromosome; they are united by a centromere
chromatids
the dense, constricted portion of a chromosome to which a spindle fiber is attached
centromere
a specialized protein complex that develops on the vertical face of a centromere during late prophase; spindle fibers are attached to it
kinetochore
structures consisting of microtubules that assist in chromosome separating during cell division
spindle fibers
stage of mitosis or meiosis in which sister chromatids line up along the equatorial plane
metaphase
an aggregation of fiber like threads (microtubules) that appears in cells during mitosis or meiosis
spindle
stage of mitosis or meiosis in which sister chromatids separate
anaphase
chromatid that becomes a chromosome after separation from a duplicated DNA molecule
daughter chromosomes
stage of mitosis or meiosis in which new cells become independent
telophase
the precursor of the middle lamella; it forms at the equator during telophase
cell plate
independent cell after completion of mitosis or meiosis
daughter cell
What are the differences between plant and animal cells?
plant cells have central vacuoles, plastids (chloroplasts), and cell walls
What phase is this?
interphase
What stage of mitosis is this?
prophase
What stage of mitosis is this?
metaphase
What stage of mitosis is this?
anaphase
What stage of mitosis is this?
telophase
ribosomes stud the outside of the membrane; produces new membrane, membrane protein, and secretory proteins
rough endoplasmic reticulum
lacks ribosomes on the surface and produces lipids, including steroids
smooth endoplasmic reticulum
