a "Cell" is the?
structural unit of all living things
Basic Structure of Generalized/Composite Cell includes three things, what are they?
Nucleus
Plasma membraneCytoplasm
what is the plasma membrane?
a selectively permeable phospholipid bilayer with hydrophilic heads and hydrophobic tails
what are integral proteins?
protein responsible for membrane function firmly secured in lipid bilayer
what are peripheral proteins?
protein responsible for membrane function attached loosely to integral proteins or lipids
a "Glycocalyx" refers to what?
the carbohydrate layer on a cell surface to identify a cell
in a passive process, substances pass the membrane how?
without energy input from the cell
in an active process, substances pass the membrane how?
the cell provides energy in the form of ATP to move substances across the membrane
what are the two types of passive processes?
diffusion
filtration
what are the three types of diffusion?
simple diffusion
facilitated diffusion
osmosis
what are the two types of active processes?
active transport
vesicular transport
"diffusion" refers to
the tendency of molecules to spread evenly throughout their environment along their concentration gradient from an area of high concentration to an area of low concentration
The greater the concentration difference, the ___________________
greater the rate of diffusion
what is the driving force of diffusion?
kinetic energy
"Simple diffusion" can be defined as
unassisted movement of lipid-soluble substances directly through the membrane
"Facilitated diffusion" can be defined as
transported substances move across the membrane via the assist of protein carriers or water-filled protein channels
"Osmosis" can be defined as
unassisted diffusion of a solvent across a membrane
"Filtration" can be defined as = forces water & solutes through a membrane orcapillary wall by hydrostatic pressure
water and solutes are forced through a membrane or capillary wall by hydrostatic pressure
in filtration, substances move based off their what?
pressure gradient
"vesicular transport" can be defined as?
what is it a form of?
transport across plasma or intracellular membranes via membrane-bound vesicles
define "exocytosis"
vesicular transport movement from intracellular space to extracellular space
define "endocytosis"
vesicular transport movement from extracellular space to intracellular space
define "active transport"
transport requiring ATP against the concentration gradient via carrier proteins
define "phagocytosis"
solid material engulfed by the cell
define "pinocytosis"
extracellular fluid containing dissolved molecules engulfed by the cell
"tight junctions" are defined as what?
where can you find them?
integral proteins in plasma membranes that form impermeable attachments between cells
gastrointestinal tract
"desmosomes" are defined as what?
where can you find them?
anchoring junctions that allow the cell to withstand tension
skin
"gap junctions" are defined as what?
where can you find them?
communicating junctions connected by hollow protein cylinders called connexons that serve as channels for transport
electrically excitable tissue in the heart
"Cytosol" is defined as
viscous fluid that suspends other cytoplasmic elements
"Organelles" is defined as
machinery each with specific function to maintain cell activity
are ribosomes considered membranous organelles?
no
what are microtubules?
what type of movements are they involved in?
cytoskeleton organelle that supports the cell and give it shape
involved in intracellular and extracellular movements
what are microfilaments
what type of movements are they involved in?
cytoskeleton organelle involved in muscle contraction and intracellular movement
what are intermediate filaments?
stable elements that compose the cytoskeleton and resist against mechanical forces
what are microvilli?
cellular extensions that increase the surface area for absorption
what are cilia?
cellular extensions that propel substances across the surface of the cell in coordinated unidirectional movement
are centrioles a cytoskeleton organelle?
yes
what are ribosomes?
site of protein synthesis
what is the function of the smooth endoplasmic reticulum?
membranous organelle that is the site of cholesterol and lipid synthesis
what is the Golgi apparatus?
membranous organelle that packages, modifies, and sorts proteins for exocytosis
what are mitochondria?
membranous organelle that is the site of ATP synthesis, contains folds of cristae that increase surface area to maximize ATP synthesis
what is the rough endoplasmic reticulum
membranous organelle that is responsible for storing ribosomes as well as transporting the ribosomes to the Golgi apparatus
what is the function of centrioles?
ensures the correct amount of DNA goes to each cell after mitosis as well as the organization of microtubules
what is the nucleus?
cell's control center that creates DNA
what is the function of the nucleolus?
creates RNA and ribosomes
what is the nuclear envelope?
outer boundary of the nucleus that separates it from the cytoplasm
what are nuclear pores?
openings on the nuclear envelope that allows small molecules like proteins and RNA in and out of the nucleus