Chapter 3: Nonenzymatic Protein Function / Protein Analysis Flashcards
List the 5 primary structural proteins:
collagen, elastin, keratins, actin, and tubulin
Collagen
has a characteristic trihelical fiber
makes up most of the extracellular matrix of connective tissue
found throughout the body and provides STRENGTH AND FLEXIBILITY
Elastin
one of the primary structures of protein in the body
important component of the extracellular matrix of connective tissue
for STRETCH AND RECOIL to restore original shape of the tissue
Keratin
one of the primary structures of protein in the body
intermediate filament proteins found in epithelial cells
contribute to mechanical integrity of the call and also function as regulatory proteins
primary protein that makes up HAIR AND NAILS
Actin
makes up ** microfilaments** and **THIN FILAMENTS **in myofibrils
have ** polarity ** to allow motor proteins to travel unidirectionally along an actin filament
what is the most abundant protein in eukaryotic cells?
actin
Tubulin
makes up microtubules
3 microtubule functions
provide structure, chromosome separation in mitosis and meiosis, intracellular transport with kinesin and dynein
Motor proteins
responsible for muscle contraction and cellular movement (cilia / flagell)
may display enzymatic activity such as ATPases (power conformational change for motor function)
list 3 common motor proteins
myosin
kinesin
dynein
Myosin
- primary motor protein that interacts with actin (thick filament in myofibril)
- can be involved in cellular transport
- each subunit has a single head and neck
- movement at the neck is responsible for the power stroke of sarcomere contraction
Kinesins and dyneins
the motor proteins associated with microtubules
they have two heads; at least one remains attached to tubulin at all times
Kinesin moves towards..
the positive end of the microtubule / the outer membrane
Dyneins move toward
the negative end of the microtubule / toward the nucleus
Binding proteins
acts as an agent to bind two or more molecules together
??
Cell Adhesion Molecules (CAMs)
Allow cells to bind to other cells or surfaces
3 categories of cell adhesion molecules
cadherins
integrin
selectins
Cadherins
calcium dependent glycoproteins that hold similar cells together
Integrin
ADHERE A CELL TO A PROTEIN
play important role in cell signaling
Selectins
ADHERE A CELL TO A CARB
most commonly used in the immune system
Immunoglobulins (antibodies)
neutralize targets in the body, such as toxins and bacteria, and then recruit other cells to help eliminate the threat
Y-shaped proteins made up of 2 identical heavy chains and 2 identical light chains
Antigen binding region
a region on the tips of the Y with specific polypeptide sequences that will bind ONE and only one specific antigenic sequence
Antigen constant region
the part of the antigen that is NOT the binding region
involved in recruitment of other immune system cells (ex. macrophages)
What are the 3 possible outcomes once an antibody binds to its target antigen?
-
neutralize the antigen
- makes the pathogen unable to exert its effect on the body
- marks the pathogen for destruction by other white blood cells immediately (opsinization)
- agglutinate (clump together) the antigen and antibody into large insoluble protein complexes that can be phagocytized and digested by macrophages