Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
structural proteins |
compose the cytoskeleton, anchoring proteins, and much of the extracellular matrix; generally fibrous in nature most common examples: collagen elastin keratin actin tubulin |
|
motor proteins |
have one or more heads capable of force generation through a conformational change; have catalytic activity, acting as ATPases to power movement; muscle contraction, vesicle movement within cells, and cell motility are the most common applications of motor proteins most common examples: myosin kinesin dynein |
|
binding proteins |
bind a specific substrate, either to sequester it in the body or hold its concentration at a steady state |
|
cell adhesion molecules (CAMs) |
allow cells to bind to other cells or surfaces include: cadherins integrins selectins |
|
cadherins |
a type of cell adhesion molecule (CAM); calcium-dependent glycoproteins that hold similar cells together |
|
integrins |
a type of cell adhesion molecule (CAM); have two membrane-spanning chains (means that they are attached to the outside of the membrane with two projections) and permit cells to adhere to proteins in the extracellular matrix; some also have signaling capabilities |
|
selectins |
a type of cell adhesion molecule (CAM); allow cells to adhere to carbohydrates on the surfaces of other cells and are most commonly used in the immune system
|
|
antibodies (or immunoglobulins, Ig) |
used by the immune system to target a specific antigen, which may be a protein on the surface of a pathogen or a toxin immunoglobulins contain a constant region and a variable region; the variable region is responsible for antigen binding two identical heavy chains (the Y looking part) and two identical light chains (the V looking part) form a single antibody; they are held together by disulfide linkages and noncovalent interactions |
|
ion channels |
can be used for regulating ion flow into or out of a cell three main types: ungated channels voltage-gated channels ligand-gated channels |
|
ungated channel |
an ion channel which is always open; responsible for maintaining the resting membrane potential |
|
voltage-gated channel |
an ion channel which is open within a range of membrane potentials |
|
ligand-gated channel |
an ion channel which is open in the presence of a specific binding substance, usually a hormone or neurotransmitter |
|
enzyme-linked receptors |
participate in cell signaling through extracellular ligand binding and initiation of second messenger cascades |
|
G protein-coupled receptors |
have a membrane-bound protein associated with a trimeric G protein; also initiate second messenger systems ligand binding engages the G protein GDP is replaced with GTP; the α subunit dissociates from the β and γ subunits the activated α subunit alters the activity of aldenylate cyclase or phospholipase C GTP is dephosphorylated to GDP; the α subunit rebinds to the β and γ subunits |
|
electrophoresis |
uses a gel matrix to observe the migration of proteins in response to an electric field types: native PAGE SDS-PAGE isoelectric focusing |
|
native PAGE |
type of electrophoresis which maintains the protein's shape, but results are difficult to compare because the mass-to-charge ratio differs for each protein |
|
SDS-PAGE |
type of electrophoresis which denatures the proteins and masks the native charge so that comparison of size is more accurate, but the functional protein cannot be recaptured from the gel |
|
isoelectric focusing |
type of electrophoresis which separates proteins by their isoelectric point (pI); the protein migrates toward an electrode until it reaches a region of the gel where pH=pI of the protein |
|
chromatography |
separates protein mixtures on the basis of their affinity for a stationary phase or a mobile phase types: column chromatography ion-exchange chromatography size-exclusion chromatography affinity chromatography |
|
column chromatography |
uses beads of a polar compound, like silica or alumina (stationary phase), with a nonpolar solvent (mobile phase) |
|
ion-exchange chromatography |
uses a charged column (the beads) and a variably saline eluent |
|
size-exclusion chromatography |
relies on porous beads; larger molecules elute first because they are not trapped in the small pores |
|
affinity chromatography |
uses a bound receptor or ligand and an eluent with free ligand or a receptor for the protein of interest |
|
X-ray crystallography |
the primary method used to determine protein structure after the protein is isolated |
|
nuclear magnetic resonance (NMR) spectroscopy |
another method also used to determine protein structure after protein is isolated |
|
hydrolysis |
a reaction involving the breaking of a bond in a molecule using water; can be used to determine amino acid composition |
|
Edman degradation |
sequential degradation which can be used for amino acid sequencing; proceeds from the amino (N-) terminus |
|
activity levels for enzymatic samples are determined by |
following the process of a known reaction, often accompanied by a color change |
|
protein concentration is determined |
colorimetrically, either by UV spectroscopy or through a color change reaction methods include: BCA assay Lowry reagent assay Bradford protein assay |
|
Bradford protein assay |
uses a color change from brown-green to blue to measure protein concentration |