Chapter 4 Vocab Flashcards
the scientific theory that the cell is the basic unit of life, of which all living things are composed, and that all cells are derived from pre-existing cells
Cell Theory
the selectively permeable surface membrane that encloses the cell contents an through which all materials entering or leaving the cell must pass
Plasma Membrane
1 of the specialized structures within the cell, such as the mitochondria, Golgi complex, ribosomes, or contractile vacuole, many are membrane-enclosed; carry out cell activities
Organelles
minute projections of the plasma membrane that increase the surface area of the cell; found mainly in the intestine or kidney tubules
Microvilli
microscope in which light is refracted (bent) by glass lenses to produce a. magnified image
Light Microscope
the capacity to distinguish fine detail in an image
Resolution
proteins derived from the immune system
Antibodies
a microscope capable of producing high-resolution, highly magnified images through the use of an electron beam (rather than light)
Electron Microscope
the fine detail of a cell, generally only observable by use of an electron microscope
Ultrastructure
the technique used to separate the components of cells by subjecting them to centrifugal force
Cell Fractionation
a device used to separate cells or their components by centrifugal force
Centrifuge
separation of cell particles according to their mass, size, or density
Differential Centrifugation
procedure in which cell components are placed in a layer on top of a density gradient
Density Gradient Centrifugation
a cell that lacks a nucleus and other membrane-enclosed organelles; includes bacteria and archaea
Prokaryotic Cells
an organism whose cells have nuclei and other membrane-enclosed organelles
Eukaryotic Cell
a molecule consisting of one or more phosphate groups, 5-carbon sugar, and a nitrogenous base
Nucleoid
the structure outside the plasma membrane of certain cells; may contain cellulose (plant cells), chitin (fungal cells), peptidoglycan and/or lipopolysaccharide (bacteria cells)
Cell Walls
a long whiplike structure extending from certain cells and use locomotion
Flagella
small complexes of RNA and protein that synthesizes polypeptieds
Ribosomes
the plasma membrane and cell contents with the exception of the nucleus
Cytoplasm
the contents of the cell nucleus
Nucleoplasm
the fluid component of the cytoplasm in which the organelles are suspended
Cytosol
a cell organelle in eukaryotes that contains the DNA and serves as the control center of the cell
Nucleus
consists of 2 concentric membranes that separate the nuclear contents from the surrounding cytoplasm
Nuclear Envelope
structures in the nuclear envelope that allows passage of certain materials between the cell nucleus and the cytoplasm
Nuclear Pores
a segment of DNA that serves as a unit of hereditary information
Genes
RNA that specifies the amino acid sequence of a protein; transcribed from DNA
Messenger RNA (mRNA)
the complex of DNA and protein that makes up eukaryotic chromosomes
Chromatin
structures in the cell nucleus that consist of chromatin and contain the genes
Chromosome
specialized structure in the cell nucleus formed from regions of several chromosomes
Nucleolus
makes up ribosomes; part of the the protein synthesis machinery
Ribosomal RNA (rRNA)
the group of membrane structures in eukaryotic cells that interact through direct connections by vesicles
Endomembrane System
small cytoplasmic vesicles that move substances from one membrane to another
Transport Vesicles
the space enclosed by a membrane
Lumen
an interconnected network of internal membranes in eukaryotic cells enclosing a compartment, ER Lumen. Rough ER has ribosomes while smooth does not
Endoplasmic Reticulum (ER)
proteins that help other proteins fold properly
Molecular Chaperones
protein complexes that direct the destruction of defective proteins
Proteasomes
organelle composed of stacks of flattened, membranous sacs; responsible for modifying, packaging, and sorting proteins
Golgi Complex
stacks of flattened membraneous sacs that make up the Golgi complex
Cisternae
small sacs of digestive enzymes dispersed in the cytoplasm
Lysosome
a cellular process in which lysosomes digest, process, and recycle the contents of a unneeded or damaged cell
Autophagy
a fluid-filled, membrane-enclosed sac found within the cytoplasm
Vacuole
membrane of the vacuole
Tonoplast
hydrostatic pressure that develops within a walled cell and presses outward against the plasma membrane
Turgor Pressure
remove excess water from the cell
Contractile Vacuoles
membrane-enclosed organelles containing enzymes that produce or degrade hydrogen peroxide
Peroxisomes
intracellular organelles that are the sites of oxidative phosphorylation in eukaryotes; powerhouse of the cell
Mitochondria
membranous organelles that are the sites of photosynthesis in eukaryotes
Chloroplasts
the hypothesis that certain organelles such as the mitochondria and chloroplasts originated as symbiotic prokaryotes that lived inside other free-living prokaryotic cells
Serial Endosymbiosis
oxygen-requiring process that includes most of the reations that convert the chemical energy present in certain foods to ATP
Aerobic Respiration
the compartment formed between the outer and inner mitochondrial membranes
Intermembrane Space
the compartment enclosed by the inner mitochondrial membrane
Matrix
shelflike or fingerlike inward projections of the inner membrane of a mitochondrion
Cristae
programmed cell death
Apoptosis
uncontrolled cell death
Necrosis
any group of proteolytic enzymes that are active in the early stages of apoptosis
Caspases
toxic, highly reactive compounds with unpaired electrons that bonds with other compounds in the cell and interfere with normal function
Free Radicals
a set of reactions during which light energy is transformed into the chemical energy of glucose and other carbohydrates
Photosynthesis
membranous organelles that are the sites of photosynthesis in eukaryotes
Chloroplasts
a green pigment that traps light energy for photosynthesis
Chlorophyll
a group of yellow to orange plant pigments synthesized from isoprene subunits; include carotenes and xanthophylls
Carotenoids
a fluid space of the chloroplast, enclosed by the chloroplast inner membrane and surrounding the thylakoids
Stroma
an interconnected system of flattened, saclike, membranous structures inside the chloroplast
Thylakoids
a stack of thylakoids within a chloroplast
Grana
thylakoid membrane encloses the innermost compartments within the chloroplast
Thylakoid Lumen
produce and store food materials in cells of plants and algae
Plastids
organelles that are plastid precursors; may mature into various specialized plastids, including chloroplasts, chromoplasts, or leukoplasts
Proplastids
pigment-containing plastids; found mainly in flowers and fruits
Chromoplasts
unpigmented plastids
Leukoplasts
used to store starch
Amyloplasts
a dense network of protein fibers, gives cells mechanical strength, shape and their ability to move
Cytoskeleton
hollow cylindrical fibers consisting of tubulin protein subunits
Microtubules
protein that makes up microtubules
Tubulin
structural proteins that help regulate microtubule assembly and cross-link microtubules to other cytoskeletal polymers
Microtubule-Associated Proteins (MAPs)
moves organelles toward the plus end of a microtubule
Kinesin
transports organelles in the opposite direction, toward the minus end
Dynein
the region of the cell from which microtubules are anchored and possibly assembled
Microtubule Organizing Centers (MTOCs)
an organelle in animal cells that is the main microtubule-organizing center; typically contains a pair of centrioles and is important in cell division
Centrosome
1 of a pair of small, cylindrical organelles lying at right angles to each other near the nucleus in the cytoplasm of animal cells and certain protist and plant cells
Centriols
framework for the orderly distribution of chromosomes during cell division
Mitotic Spindle
1 of many short, hairlike structures that project from the surface of some eukaryotic cells and are used for locomotion or movement of materials across the cell surface
Cilia
structure involved in the organization and anchorage of a cilium or flagellum
Basal Body
single nonmotile cilium on the cell surface of animal cells; binds specific molecules and serves as a “cellular antenna” in many signaling pathways
Primary Cilium
flexible, solid fibers
Microfilaments
the protein of which microfilaments consist; responsible for muscle contraction
Actin
a protein that together with actin is responsible for muscle contraction
Myosin
a temporary extension of an amoeboid cell that is used for feeding and locomotion (“false feet”)
Pseudopodia
cell coat; formed by polysaccharides
Glycocalyx
organize the matrix and help cells attach to it
Fibronectins
