Cell Structure Flashcards
All cells share four common components:
Plasma membrane
Cytoplasm
DNA
Ribosomes
Acts as the boundary between the outside and inside of a cell.
The integrity and function of the plasma membrane are vital to a cell because this membrane acts much like a gatekeeper, regulating the passage of molecules and ions into and out of the cell.
The plasma membrane is composed of a phospholipid bilayer.
Plasma Membrane
the phospholipids are at the surfaces of the membrane
Polar heads
make up the interior of the membrane.
Non-polar tails
A semifluid interior, where chemical reactions occur.
Dense gelatinous solution of sugars, amino acids, & salts
Serves as solvent for materials used in all cell functions
Cytoplasm
Geneticmaterial of all cellular organisms and most viruses.
Made out of sugars (deoxyribose), phosphates and nitrogen bases
Deoxyribonucleic Acid
DNA carries the information needed to direct ___
Protein synthesis and DNA replication
Is a complex molecule made of ribosomal RNA molecules and proteins that form a factory for the protein synthesis in cells.
Ribosomes
Who discovered that small particles in the cytoplasm that preferentially associated with the endoplasmic reticulum membrane.
George E. Palade in 1955
rotates 360o
1-2 or many distributed over entire cell
functions in motility
Flagella
A part of flagella that is long, thin, helical structure composed of proteins
Filament
A part of flagella that is curved sheath
Hook
A part of flagella that is stack of rings firmly anchored in cell wall
Basal Body
single flagellum at one end
Monotrichous
small bunches arising from one end of cell
Lophotrichous
flagella at both ends of cell
Amphitrichous
flagella dispersed over surface of cell, slowest
Peritrichous
fine hairlike bristles from the cell surface
function in adhesion to other cells and surfaces
Fimbriae
rigid tubular structure made of pilin protein
Functions
joins bacterial cells for DNA transfer (conjugation)
adhesion
Pili
Coating of molecules external to the cell wall, made of sugars and/or proteins
functions:
attachment
inhibits killing by white blood cells
receptor
Glycocalyx
Type of glycocalyx that is highly organized, tightly attached
Capsule
Type of glycocalyx that is loosely organized and attached
Slime layer
Peptidoglycan
provides strong, flexible support to keep bacteria from bursting or collapsing because of changes in osmotic pressure
Cell Wall
single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell
Chromosome
DNA is tightly coiled around a protein, aggregated in a dense area called the
Nucleoid
may encode antibiotic resistance, tolerance to toxic metals, enzymes & toxins
Plasmids
– intercellular layer composed of pectin. Pectin is a viscous and gelatinous substance which acts as a cementing material to hold the cells together.
Middle Lamella
consists mainly of bundles of intertwined molecules of cellulose, cutin and waxes
Primary wall
produced and deposited between the primary wall and the protoplast after cell enlargement ceases and is composed mainly of cellulose and lignin. Lignin is a complex material responsible for hardness and decay-resisting qualities of many woods.
Secondary wall
Protoplasmic connections which aid in the movement of materials from one cell to another
microscopic channels which traverse the cell walls of plant cells enabling transport and communication between them
Plasmodesmata
Essential in food making and storage of food
Plastids
young plastids capable of dividing, usually colorless
Proplastid
colored plastids containing red, yellow or orange pigments
Chromoplastids
contain the green pigment chlorophyll
Chloroplastids
colorless plastid and usually functions for storage
Leucoplastids
stores starch
Amyloplastid
stores oil
Elaioplastid
stores protein
Aleuroneplastid
evaginations or projections, microscopic cellular membrane protrusions that increase the surface area of cells, and are involved in a wide variety of functions, including absorption and secretion
Microvilli
small indentations in the plasma membrane
Caveolae
help to organize the assembly of microtubules during cell division.
Centrioles
transport system of the cell
Endoplasmic Reticulum
– has attached ribosomes and is involved in protein synthesis
Rough ER
– involved in synthesis and breakdown of lipid and carbohydrate
Smooth ER
Folded inner membrane of Mitochondrion called
Cristae
-powerhouse of the cell
-sites of cellular respiration, the metabolic process that generates ATP by extracting energy from sugars, fats, and other fuels with the help of oxygen.
Mitochondrion
also called dictyosome, modifies, packages and distributes molecules made at one location of the cell and used at another.
Golgi Bodies
– small membrane-bordered structures that contain chemicals and enzymes necessary for digesting certain materials in the cell.
-They are formed in the Golgi bodies. They are known as suicidal bags for they can destroy cell structures that have outlived their usefulness
Lysosomes
-composed of a variety of filaments and fibers that support cell structure and drive cell movement.
-Helps cell maintain cell shape
Cytoskeleton
contain long thin cylindrical fibrils that provide support for cell shape and help move organelles through the cell and during cell division.
Microtubules
contains actin for movement and support of the cell. They also permit movement of the cytoplasm within the cell called cytoplasmic streaming
Microfilament
store materials like water, salts, proteins and carbohydrates
Vacuoles
control center of the cell
Nucleus
-Surrounds nucleus
-Also called nuclear envelope
Nuclear Membrane
The liquid inside the nucleus
-Also called Karyoplasm
Nucleoplasm
Produces ribosomes
Nucleolus
ATP
Adenosine Triphosphate
They also permit movement of the cytoplasm within the cell called
Cytoplasmic Streaming
