test 3 cell structure & function Flashcards
cytology
the study of cells
ingestion
the ability to take in nutrients; this includes absorption, which is the ability to bring dissolved materials into the cell
digestion
the ability to break food or nutrients down into simpler forms (by hydrolysis or with the help of enzymes) so it can be utilized
respiration
the ability to release energy from the breakdown of food molecules
transport
the ability to distribute or circulate molecules from one part of a cell to another
secretion
the ability to release biosynthesized substances
excretion
the ability to remove soluble metabolic waste from the cell
egestion
the ability to remove non soluble, undigested waste from the cell
irratability
the ability to respond to stimuli
organelle
a tiny cellular structure that carries out a specific function necessary for the cell to survive
prokaryotic cell
a cell that has no nucleus or other distinct, membrane bound organelles
eukaryotic cells
a cell with a membrane bound nucleus and other distinct, membrane bound organelles
plasma membrane
the semipermeable membrane between the cells contents and the cells surrounding
cytoplasm
the jelly like fluid inside the cell in which the organelles are suspended
cytoplasmic streaming
the motion of cytoplasm in a cell that results in a coordinated movement of the cells contents
ribosomes
non membrane bound organelles responsible for protein synthesis
cell wall
the rigid structure on the outside of certain cells usually plant and bacteria cells
middle lamella
the thin film between the cells walls of adjacent plant cells
nuclear membrane
a highly porous membrane that separates the nucleus from the cytoplasm
chromatin
long strands of clusters of DNA and proteins (or RNA and proteins) in the nucleus of the cell
endoplasmic reticulum
an organelle composed of an extensive network of folded membranes that performs several tasks within a cell
rough ER
ER that is dotted with ribosomes
smooth ER
ER that has no ribosomes
golgi apparatus
the organelles where proteins and lipids are stored and then modified to suit the needs of the cell
vacuole
larger membrane bound organelles used for storage of food, water or waste
vesticle
smaller membrane bound organelles used mainly for transport of food, waste or products synthesized for secretion
secretory vesicle
vesicle that holds products of biosynthesis (like proteins) and transports them to the plasma membrane for secretion
central vacuole
a large vacuole that rests at the center of most plant cells and is filled with water
lysosomes
the organelle in animal cells responsible for hydrolysis reactions that break down proteins, carbohydrates (disaccharide, polysaccharides) and some lipids
peroxisome
a cell organelle containing enzymes that catalyze the decomposition of fatty acids and hydrogen peroxide
mitochondria
double membrane bound organelles in which nutrients re converted to energy
plastids
double membrane bound organelles found in the cells of plants, algae, and some protazoa, generally involved in either the manufacture or storage of food
chloroplast
plastids containing the green pigament, chlorophyll, used in photosynthesis
chromoplasts
plastids containing yellow, orange, ot red pigments used in photosynthesis
leucoplasts
nonpigmented plastids that store starches or oils
cytoskeleton
a network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
microfilaments
fine, thread like proteins found in the cells cytoskeleton
intermediate filaments
threadlike proteins in the cells cytoskeleton that are roughly twice as thick as the microfilamenets
microtubules
spiral strands of protein molecules that form a tubelike structure
centrioles
paired organelles (positioned at right angles to eachother) that organize fibers required for cell division; found in animal cells
centrosome
a small region near the nucleus that is the min organizing site for microtubules; in animal cells it contains two centrioles
fluid mosaic model
a model propossing that the plasma membrane is composed of a mosaic of components (mainly phospholipids proteins and cholesterol) that are free to move fluidly within the plane of the membrane
phospholipid
a lipid in which one of the fatty acid molecules has been replaced by a molecule that contains a hydrophilic phosphate group
semipermeable membrane
a membrane that allows some molecules to pass through but does not allow other molecules to pass through
passive transport
movement of molecules through the plasma membrane without the need for energy input
active transport
movement of molecules through the plasma membrane aided by a process that requires energy input
concentration
a measurment of how much solute exists within a certain volume of solvent
concentration gradient
the difference in the concentration of like molecules in two areas, like on each side of the plasma membrane
diffusion
the random motion of molecules from an area a high concentration to an area of low concentration (with an concentration gradient) until its concentration becomes equal throughout the area (reaches equilibrium)
osmosis
the diffusion of water through a semipermeable membrane from and area of high water concentration (low solute concentration) to a low water conentration (high solute concentration)
HYPOtonic solution
a solution that has a low solute concentration (and so a high water concentration) relative to another solution
HYPERtonic solution
a solution that has a high solute concentration (and so a low water oncentration) relative to another solution
ISOtonic solution
a solution that has the same solute concentration (and water concentration) relative to another solution
plasmolysis
collapse of a walled cell’s cytoplasm due to a lack of water (hypertonic solution)
cytolysis
the rupturing of a cell due to excess internal pressure (hypotonic solution)
facilitated diffusion
the movement of certain molecules across the cell membrane through protein channels from high concentration to low concentration
endocytosis
the process of moving particals into the cell by means of vesicals forming from the cells membrane
exocytosis
the process of moving particles out of the cell by means of vesicle membranes fusing with the cell membrane
phagosytosis
the endoctic process by which a cell engulfs large, solid particles or cells
pinocytosis
the endocytic process by which a cell absorbs extracellular fluid containing dissolves particles
what are the three main ideas of the cell theory?
- all living organisms are composed of cells. they may be unicellular or multicellular.
- the cell is the basic structure and function in living organisms.
- all cells arise from other cells
describe the similareties and differences between prokayryotic cells and eukaryotic cells.
eukaryotic cells contain
-SER
-RER
- a nucleus
-other membrane bound organelles
-golgi apparatus
-vacuole
-vesicle
-cytoskeleton
-centrioles
prokaryotic cells do not have these. all of the other components of a cell bot prokayotic and eukaryotic cells contain.
name the organelles that play a role in biosynthesis
THE SECRETORY VESICLE
a vesicle that holds products of biosynthesis (like protein) and transports them to the plasma membrane
what helps the cell hold its shape if it does not have a cell wal?
THE PLASMA MEMBRANE
the semipermeable membrane between the cell’s contents and the cell’s surroundings
how does a plant cell fight osmosis in a hypotonic solution?
the plant cell fights osmosis by making it a hypertonic solution
what are the 12 major life funtions a cell must perform?
- Ingestion IN
- digestion DI
- respiration RE
- transport TR
- homeostasis
- synthesis SYN
- secretion SE
- excretion EX
- egestion EG
- irritability IR
- movement MO
- reproduction REP
what is the plasma membrane made of? describe it in terms of the fluid mosaic model.
the plasma membrane is composed of a mosaic of components, mainly phospholipids, proteins, and cholesterol
what is the difference betweeen a phospholipid and a regular lipid?
a phospholipid id different from a regular lipid because one of the fatty acid molecules has been replaced by a molecule that contains a hydrophilic phosphate group
what makes it possible for the plasma membrane to reassemble?