Chapter 2 (Pt. 1) Flashcards
what are the three main components in a cell membrane?
phospholipids
cholesterol
proteins
what is the structure of a phospholipid? (3)
- glycerol backbone
- two fatty acid tails
- hydrophilic phosphate group
what are the two classes of membrane proteins?
integral; peripheral
which proteins are embedded in the core of the plasma membrane?
integral
which proteins extend all the way through the membrane?
transmembrane
role of transmembrane proteins? (2)
- signaling
- transport large, polar molecules across the cell membrane
which proteins do not extend through the entire bilayer?
peripheral
what are the three types of peripheral proteins?
receptors
adhesion
recognition
recognition proteins, aka
glycoproteins
ligands that bind to a receptor protein and activate its response are called:
agonists
ligands that bind to a receptor and prevent it from activating are called:
antagonists
agonists vs. antagonists?
AGONIST: bind to a receptor protein and activate its response
ANTAGONISTS: bind to a receptor and prevent it from activating
what are the three main factors that affect membrane fluidity?
-temperature
-cholesterol
-phospholipid tail unsaturation
which particles can travel directly across the phospholipid bilayer via simple diffusion?
small, uncharged, nonpolar
saturated vs unsaturated fatty acids?
SATURATED: saturated with hydrogens at each carbon, straight.
UNSATURATED: double bonds, crooked.
osmosis is a type of _______
simple diffusion
give a definition and example of simple diffusion:
flow of substances down their concentration gradient; no energy.
osmosis.
how do large, hydrophilic molecules travel across the bilayer?
facilitated transport by transmembrane proteins?
what are the three main types (directions) of facilitated transport?
- uniport
- symport
- antiport
what two classes of transmembrane proteins are involved with facilitated transport?
channel; carrier
channel vs. carrier?
CHANNEL: faces extra and intra cellular environments
CARRIER: change shape to facilitate the movement of molecules.
what are aquaporins?
porin that allows water to flow through rapidly
porins and ion channels are part of what type of diffusion?
passive
active transport tends to rely upon which type of proteins?
carrier
what are the two types of active transport?
primary; secondary
primary vs. secondary active transport?
PRIMARY: uses ATP directly
SECONDARY: uses EC gradient produced by primary active transport
can you give an example of primary active transport?
Na/K pump
what is cytosis?
bulk transport of large, polar molecules
bulk transport of large, polar molecules is called what?
cytosis
what are the two types of cytosis?
endo and exocytosis
what is a type of endocytosis where a cell engulfs undissolved materials
phagocytosis
phagocytosis forms
vacuoles (phagosomes)
what is a type of endocytosis where a cell engulfs dissolved materials?
pinocytosis (cellular drinking_
what is pinocytosis?
cellular drinking
pinocytosis forms
vesicles
receptor-mediated endocytosis forms
vesicles
organelles are enclosed by a ?
phospholipid bilayer
membrane-bound organelles are associated with which cell type?
eukaryotes
cytosol vs. cytoplasm?
cytosol: intracellular fluid
cytoplasm: everything within the cell
what is the nucleus?
membrane-enclosed organelle that contains most of a eukaryotic cell’s genetic material
do prokaryotes have a nucleus?
no they have a nucleoid
the nucleus contains an aqueous
nucleoplasm
what is the inner and outer membrane of the nucleus called?
nuclear envelope
what is the space between the inner and outer nuclear membranes?
perinuclear space
what is the nuclear lamina?
what is a dense and fibrous network of proteins associated with the inner membrane of the nuclear envelope
what is a dense and fibrous network of proteins associated with the inner membrane of the nuclear envelope
what is the nuclear lamina
_______ are a type of intermediate filament that make up the nuclear lamina
lamins
what are lamins?
a type of intermediate filament that make up the nuclear lamina
what functions to provide structural support to the nucleus, regulate DNA organization, DNA replication, and cell division
nuclear lamina
the nuclear envelope has holes called what?
nuclear pores
