NonEnzymatic Proteins

Question 1

Structural Proteins

Answer 1

Highly repetitive secondary structures and a supersecondary structure (motif): generally fibrous in nature

Ex: Collagen (3 alpha helices to create strength and flexibility)

Question 2

Actin

Answer 2

Structural Protein made of microfilaments

Question 3

Tubulin

Answer 3

Structural Protein made of microtubules

Question 4

Keratin

Answer 4

Structural Protein serving as a regulatory intermediate filament protein

Question 5

Motor Proteins

Answer 5

One or more heads capable of force generation through a conformational change

• Responsible for muscle contraction and cellular movement
• Have catalytic activity (ATPases power movements)

Ex: Myosin, kinesins, dyneins

Question 6

Binding Proteins

Answer 6

Proteins transport or isolate molecules by binding to them; have a stabilizing function

Question 7

Cell Adhesion Molecules (CAMs)

Answer 7

Allow cells to bind to other cells or surfaces

Ex: Cadherins, integrins, selectins

Question 8

Cadherins

Answer 8

Calcium dependent glycoproteins that hold similar cells together

Question 9

Integrins

Answer 9

Two membrane spanning chains (alpha and beta). Permit binding and communicating with ECM, cell signaling and processes

Question 10

Selectins

Answer 10

Allow cells to adhere to carbohydrates and are important in defense, inflammation and white blood cell migration (immune system)

Question 11

Immunoglobulins

Answer 11

Antibodies - proteins produced by B cells that target antigens which may be a protein on the surface of a pathogen (invading organism) or a toxin

Question 12

Antibody Methods

Answer 12

1. Neutralize antigen
2. Opsonization (mark pathogen for destruction)
3. Agglutinating (clump together insoluble proteins to be digested by macrophages)

Question 13

Biosignaling

Answer 13

Process by which cells receive and act on signals

Question 14

Ion Channels

Answer 14

Proteins that create specific pathways for charged molecules through facilitated diffusion (passive)

Question 15

Ungated Channels

Answer 15

Ion channels that are always open

Question 16

Voltage Gated Channels

Answer 16

Ion channels that open within a range of membrane potentials (Depolarization creates a conformational change)

Question 17

Ligand Gated Channels

Answer 17

Ion channels that open in the presence of specific binding substances (generally hormone or neurotransmitter)

Question 18

Enzyme Linked Receptiors

Answer 18

Participate in cell signaling through extracellular ligand binding and initiation of secondary messenger cascades

Question 19

G-Protein Coupled Receptors

Answer 19

Initiate secondary messenger systems:

1. Ligand binds to alpha subunit activating GTP from the inactive GDP
2. Alpha subunit dissociates from the Beta and Gamma Subunits
3. Activated Alpha alters the activity of Adenylate Cyclase or Phospholipase C
4. GTP is dephosphorylated to GDP and rebinds with the Beta and Gamma subunits

Question 20

Types of G- Proteins

Answer 20

Gs - Stimulates cAMP (increases)
Gi - Inhibits cAMP (decreases)
Gq - Activates Phospholipase C

Question 21

Homogenization

Answer 21

Crushing, grinding or blending of Cells / Tissues

Question 22

Centrifugation

Answer 22

Isolate proteins from smaller molecules

Question 23

Electrophoresis

Answer 23

Uses Polyacrylamide Gel to observe proteins migration in an electric field based on net charge and size

Question 24

Native Page

Answer 24

Analyze proteins in native states and compare the molecular size or charge of proteins
*proteins can be recaptured from gel

Question 25

SDS-Page

Answer 25

Denature protein; separates based on mass only

Question 26

Isolectric Focusing

Answer 26

Separates proteins by isoelectric point (pI) in an electric field that protein stops moving when pH = pI

Anions (-) move toward the Anode (+)
Cations (+) move toward the Cathode (-)

Question 27

Chromatography

Answer 27

Separates proteins based on their affinity for a stationary phase vs mobile phase (move farther)

Question 28

Column Chromatography

Answer 28

Polar beads (stationary) and nonpolar solvent (mobile)
The less polar the protein, the faster it will elute

Question 29

Ion Exchange Chromatography

Answer 29

separates ions and polar molecules based on their affinity to the ion exchanger (charged column)

Anion-Exchange: desired molecule is negatively charged

Cation-Exchange: desired molecule is positively charged

Question 30

Size Exclusion Chromatography

Answer 30

Porous beads capture small proteins so that large proteins elute first

Question 31

Affinity Chromatography

Answer 31

Coat beads with a receptor that binds the protein or antibody of interest

Question 32

Edman Degradation

Answer 32

Sequentially removes the N-terminus amino acid

Question 33

UV Spectroscopy

Answer 33

Analyzes protein concentrations

Question 34

Bradford Assay

Answer 34

Coomassie Brilliant Blue: Increased [ ] means increased blue color