Cell structure 1 Flashcards
______ is the study of the function of the cell
Cell physiology
outer most membrane surrounding the cell, separating the internal contents from the extracellular
plasma membrane or cell membrane
cytoplasm is cytosol +
organelles
_____ thick, semi-fluid portion of the cytoplasm which includes soluble proteins and enzymes, nutrients, ions and other small molecules
cytosol
______ highly organized structures suspended in the cytosol specialized for certain cellular activities
organelles
______ an organelle that is visible under the microscope and is the control center of the cell because the genes that code for proteins are located within it
nucleus
the cell membrane or plasma membrane surrounds the cell cytoplasm but allows transport of certain substances across it this is referred to as __________ or _________
selectively permeable or semi-permeable
_____ refers to many small parts fitting together
mosaic
_____ refers to the idea that the proteins seem to float in a sea of lipids
fluid
_____ is the most abundant component of the cell membrane
phospholipids
_______ possess polar and nonpolar ends
amphipathic
the phospholipids form a ____ (double layer)
bilayer
_____ are lipids possessing small, possibly branched carbohydrate chains
Glycolipids
______ found in both inner and outer layers of the membrane
cholesterol
________or ______ are embedded in the membrane and may span both lipid layers
integral proteins, transmembrane proteins
_______ are not imbedded in the bilayer, but are found on the inner or outer surface of the membrane attached to integral proteins
peripheral proteins
_______ some substances (polar substances such as ions like K+ and Na+) cannot pass through the lipid bilayer so instead they diffuse from one side of the membrane to the other through pores in integral proteins which span the bilayer
channels
_______ or ______these are integral proteins which allow for the movement of larger polar substances (i.e. glucose, amino acids)
transporters/carriers
____ integral proteins serving as binding sites for substances such as hormones, neurotransmitters or nutrients
receptor
______some integral and peripheral proteins serve as enzymes to catalyze reactions
enzymes
_____ integral and peripheral proteins may serve as anchors for the filaments of the cytoskeleton providing strength and shape or ____ proteins can attach the cell to neighboring cells
linker
______ glycolipids and glycoproteins act in self-identification
cell identity markers
the plasma membrane is _____
selectively permeable
selectively permeable membrane can create different chemical compositions inside and outside the cell this is called a _________
concentration gradient
substances will move down concentration gradients, from an area of higher ion or molecular concentration to an area lower in concentration, until _____ is achieved
equilibrium
______ involves the movement of substances against gradients with the requirement of ATP
active transport
requirement for transport proteins (2)
mediated transport, nonmediated transport
substances move through the membrane with the help of _________
transporter proteins
_____ involves the movement of substances down gradients through kinetic energy of the molecules
passive transport
________substances move through the membrane with the help of transporter proteins
mediated transport
_______ substances can move through the membrane without the need of transporter proteins
nonmediated transport
______ tiny spherical vesicles detach or merge with the cell membrane to carry usually larger substances (cells, cell debris, large macromolecules) out of or into the cell
vesicular transport
____ is the movement of water through a selectively permeable membrane (that doesn’t permit movement of the solute) from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration)
osmosis
osmosis is passive or active transport?
passive
____ is the passive movement of substances (solutes, solvent, gases) down their concentration (partial pressure) gradients
diffusion
polar substances require membrane proteins for diffusion. cannot cross the phospholipid bilayer so travel through ______in the proteins
channels
Diffusion rates are faster if the (4)
b. temperature is higher
c. molecules are small
d. surface area for diffusion is large
e. site of diffusion is thin
_________ occurs when a solute binds to a specific transporter on one side of the membrane and is released on the other side
facilitated diffusion