Non enzymatic protein function and protein analysis. Flashcards
CELLULAR FUNCTIONS BIOSIGNALING PROTEIN ISOLATION PROTEIN ANALYSIS
name the structural proteins found in our body
- collagen
- elastin
- keratin
- actin
- Tubulin
Elastin
Protein with stretchiness that restores tissue shape
Purpose of keratin
provide mechanical integrity to hair and nails
Purpose of collagen
Provides tissue stability and strength
Examples of motor proteins
Myosin
Kinesin
dynein
Function of myosin
sarcomere contraction
cellular transport
Function of Kinesin
Involved in metaphase and anaphase cellular process
Move towards positive end of microtubule
Function of Dynein
- sliding movement of cilia and flagella.
- Moves toward negative end of microtubule.
Which type of ion channel is unresponsive to both molecule binding and local depolarization?
Ungated channels
What is the correct sequence of events for enzyme-linked receptor activity?
Ligand binds, conformational change, catalysis
what are the means of biosignaling
Ion channels
Enzyme linked receptors
G-protein coupled receptors
Types of ion channels
voltage gated
ligand gated
ungated
purpose of ion channels
facilitate passive diffusion
Which type of of signalling receptor requires ATP to function?
G Protein-coupled receptors
Name the three types of G⍺-protein, their function, and results of activity
Gs: stimulates adenylate cyclase; increasing cAMP concentration
Gi: Inhibits adenylate cyclase; decreases cAMP concentration
Gq: activates Phospholipase C; increasing signaling molecules such as PIP2, DAG, and IP3
Which protein does NOT play a role in the propagation of action potentials in efferent neurons of the central nervous system?
G protein-coupled receptors
Glycogen breakdown in hepatocytes is activated by an increase in cAMP concentration in the cytosol. The hormone glucagon initiates the breakdown of glycogen. Which occurs first in this signaling process?
Glucagon binds to Gs coupled-protein receptors
The two methods if protein isolation
Electrophoresis and chromatography
Types of Electrophoresis
Native PAGE
SDS PAGE
Isolectric focusing
Purpose Native PAGE
undenatured protein seperation by size and charge
Purpose of SDS PAGE
separation of denatured proteins by size and charge
denaturing agent is DTT or mercaptoethanol
SDS simply adds the universal negative charge to all the proteins so that during PAGE process, the proteins are moving toward the positive end of the gel.
Purpose of Isoelectric focusing
separation based on isoelectric point (pH at which AA is has no charge)
This method focuses on acidic and basic properties
Which ion channel Is responsible for MAINTAINING the resting membrane potential?
Ungated channels
Which method of protein isolation is best for separating large quantities.
Chromatography
*Note: if pI values are significantly different then ion exclusion chromatography Is best.
If Molecular weights are significantly different then size-exclusion is best option.
Features of structural proteins
1) Embedded to cell membrane
2) highly Repetitive secondary structure
3) Provide intracellular support.
_____ are a type of stabilizing proteins that transport or sequester molecules
They also exhibit a Michaelis-Menten constant (Km) for binding affinity
Binding proteins
Examples of Binding proteins
Hemoglobin, Calcium-Binding proteins, ssDNA binding proteins
Types of cell adhesion molecules
Cadherin
Selectin
Integrins
Importance of cell adhesion molecules
- bind cell to extracellular matrix
- cell to cell connection
- targeted by certain drugs (cancer )
Types of Cadherins
P-Cadherins (Placenta)
E-cadherins (epithelial)
N-cadherins (Neural)
______ are glycoproteins that mediate adhesion of calcium-dependent cells
Cadherins
Importance of Integrins
- Cell to extracellular proteins binding
- Involved in cellular signaling
- promote cell division
- promote cell apoptosis
- promote platelet activation
- Promote white blood cell migration
Importance of selections
- bind cell to surface sugars
- found in white blood cell membrane and promotes their migration during inflammation
- Found in blood vessel cell membrane
Immunoglobin methods of ridding the body of foreign invaders
neutralization, opsonization(targeting for destruction), or agglutination
Purpose of constant region of Immunoglobulins
recruit other immune cells such as macrophages
