Biochemistry Ch3: Non enzyme protein function Flashcards
Define Collagen (3) characteristics
Trihelical
makes up most of the extracellular matrix of connective tissue
provides strength and flexibility
Define Elastin
primary focus is to stretch and recoil like a spring, restoring original shape
Define Keratins
intermediate filament proteins
mechanical integrity of cell
found primarily in nails and hair
Define actin
makes up microfilaments
most abundant in eukaryotic cells
contain positive and negative side
allows motor proteins to move unidirectionally
define Tubulin
Makes up micro tubules chromosome separation in mitosis intracellular transport inside of cell using kinesin and dynein (-) end usually near the nucleus (+) end usually near plasma membrane
define Myosin
motor protein that interacts with actin
cellular transport
they have a head and a neck
involved with sarcomere contraction
Kinesins
play a role in aligning chromosomes during metaphase and deploymeration during anaphase
vesicles transport
takes molecules from the negative to the positive end
Dyneins
movement of flagella and cillia
sliding movement
vesicles transport
takes molecules from the positive to the negative end
Cell adhesion molecules (CAMs)
proteins found on the cell surface of cells, integral membrane proteins, they are split into three families cadherins, integrins and selectins
Cadherins
glycoproteins that mediate calcium- dependent cell adhesion
they hold similar cells types together (epithelial and epithelial)
cell types have specific cadherins
Integrins
they have alpha and beta sections, they bind and communicate with the extracellular matrix, play a role in cell signaling
(cell migration, cell division)
Selectins
they bind to carbohydrate molecules that project from other cell surfaces (expressed on white blood cells)
Immunoglobulins
Antibodies y shape two regions antigen variable region and constant region neutralize antigen mark pathogens agglutinating pathogens
Opsoinization
marking pathogen for destruction
define biosignaling
cells receive and act on signaling
Ion Channels
proteins that create a pathway for charged molecules to pass through the plasma membrane three kinds of Ion channels ungated voltage gated ligand gated
ungated ion channel
they have no gates, unregulated, depends on equilibrium of the ion i question (example K+)
Voltage gated channels
regulated by membrane potentials near the channel gate
closed in resting positions
they quickly open and close
Ligand gated channels
they need to be opened and closed using the binding of a ligand to the channel
Enzyme linked receptors
they can also display catalytic activity they have three domains membrane spanning domain ligand binding domain catalytic domain
membrane spanning domain
anchors the receptor to the cell membrane
ligand binding domain
stimulated by the appropriate ligand and induces a conformational change in the receptor to activate the catalytic domain
catalytic domain
when this is activated it activates a secondary messenger cascade
G - Protein - Coupled- Receptors
large family of signaling proteins and they are involved in signaling tranduction
ligand binds and ups the chances of a g protein to be attached to the protein
once a gprotien is added the receport is activated
G- protein
they link to guanine nucleotides (GTP and GDP)
three main types of g proteins
G(s)
stimulates adenylate cyclase, increases the levels of cAMP in the cell
G(i)
inhibits adenylate cyclase, decreases the levels of cAMP in the cell
G(q)
activates phospholipase C
cleaves phosphate from the membrane to form PIP1 and PIP2
this can lead to the cleavage of DAG and IP3
this then opens calcium channels in the endoplasmic reticulum
what are the three subunits that make up the Gprotien
alpha beta and gamma
what is the inactive form of gprotien
beta gamma and alpha GDP
what is the active form of the gprotien
beta gamma and alpha GTP
explain active g protein to inactive g protein
beta and gamma stick together
alpha subunit GTP seperates and enzyme adenylate cyclase removes a phosphate group turning the alpha GTP into alpha GDP
creating a inactive g protien
beta and gamma and alpha GDP
electrophoresis
separate molecules using electric charge by their electric charge and their size
their migration depends on their migration velocity
Native Page
analyze proteins in their native states
it is used mostly to determine the charge of the protien in question
SDS Page
SDS (Sodium Dodecyl Sulfate)
separates proteins on the bases of mass alone
SDS makes all the proteins negative and it denatures the proteins (its a detergent)
therefore allowing the only variable present to be mass of the protien
Isoelectric Focusing
protiens seperated based on their pI (isoelectric point) the pI is the pH at which the protien or amino acid is electrically neutral (zwittron) in the amino acid
when the protien stops moving pH=pI
anode - acidic (+) charge
Chromatography
require homogenized protien mixture to be fractured through a porous matrix
preferred when using large amounts of protien
purpose is to use the similarity in characteristics (charge size ect) to see how far the protien migrates
