3.1 Protein cellular functions

Question 2

List the 5 primary structural proteins:

Answer 2

collagen, elastin, keratins, actin, and tubulin

Question 3

Collagen

Answer 3

has a characteristic trihelical fiber

makes up most of the extracellular matrix of connective tissue

found throughout the body and provides STRENGTH AND FLEXIBILITY

Question 4

Elastin

Answer 4

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

Question 5

Keratin

Answer 5

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

Question 6

Actin

Answer 6

makes up ** microfilaments** and **THIN FILAMENTS **in myofibrils

have ** polarity ** to allow motor proteins to travel unidirectionally along an actin filament

Question 7

Tubulin

Answer 7

makes up microtubules

Question 8

Motor proteins

Answer 8

responsible for muscle contraction and cellular movement (cilia / flagell)

may display enzymatic activity such as ATPases (power conformational change for motor function)

Question 9

Myosin

Answer 9

• 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

Question 10

Kinesins and dyneins

Answer 10

the motor proteins associated with microtubules

they have two heads; at least one remains attached to tubulin at all times

Question 11

Kinesin moves towards..

Answer 11

the positive end of the microtubule / the outer membrane

Question 12

Dyneins move toward

Answer 12

the negative end of the microtubule / toward the nucleus

Question 13

Binding proteins

Answer 13

acts as an agent to bind two or more molecules together

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Question 14

Cell Adhesion Molecules (CAMs)

Answer 14

Allow cells to bind to other cells or surfaces

Question 15

Cadherins

Answer 15

calcium dependent glycoproteins that hold similar cells together

Question 16

Integrin

Answer 16

ADHERE A CELL TO A PROTEIN

play important role in cell signaling

Question 17

Selectins

Answer 17

ADHERE A CELL TO A CARB

most commonly used in the immune system

Question 18

Immunoglobulins (antibodies)

Answer 18

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

Question 19

Antigen binding region

Answer 19

a region on the tips of the Y with specific polypeptide sequences that will bind ONE and only one specific antigenic sequence

Question 20

Antigen constant region

Answer 20

the part of the antigen that is NOT the binding region

involved in recruitment of other immune system cells (ex. macrophages)

Question 21

What are the 3 possible outcomes once an antibody binds to its target antigen?

Answer 21

• 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

Question 22

what is the most abundant protein in eukaryotic cells?

Answer 22

actin

Question 23

3 microtubule functions

Answer 23

provide structure, chromosome separation in mitosis and meiosis, intracellular transport with kinesin and dynein

Question 24

list 3 common motor proteins

Answer 24

myosin
kinesin
dynein

Question 25

3 categories of cell adhesion molecules

Answer 25

cadherins
integrin
selectins