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