General Protein Functions

Question 1

Enzymes

Answer 1

catalyze covalent bond breakage/formation

Question 2

Structural Proteins

Answer 2

provide mechanical support to cells and tissues

Question 3

Transport Proteins

Answer 3

carry small molecules/ions

Question 4

Motor Proteins

Answer 4

generate movement in cells and tissues

Question 5

Storage Proteins

Answer 5

store amino acids/ions

Question 6

Signal Proteins

Answer 6

carry extracellular signals from cell to cell

Question 7

Receptor Proteins

Answer 7

detect signals and transmit them to the cell’s response machinery

Question 8

Transcription Regulators

Answer 8

bind to DNA to switch genes on/off

Question 9

Special-Purpose Proteins

Answer 9

highly variable functions

Question 10

Alcohol Dehydrogenase

Answer 10

enzyme

makes the alcohol in wine

Question 11

Pepsin

Answer 11

enzyme

degrades dietary proteins in the stomach

Question 12

Ribulose Bisphosphate Carboxylase

Answer 12

enzyme

helps convert CO2 into sugars in plants

Question 13

DNA Polymerase

Answer 13

enzyme

copies DNA

Question 14

Protein Kinase

Answer 14

enzyme

adds a phosphate to a protein

Question 15

Collagen

Answer 15

structural protein
common constituent of ECM
forms fibers in tendons and ligaments

Question 16

Elastin

Answer 16

structural protein
common constituent of ECM
forms fibers in tendons and ligaments

Question 17

Tubulin

Answer 17

structural protein

forms long, stiff microtubules inside cell

Question 18

Actin

Answer 18

structural protein

forms filaments that support plasma membrane

Question 19

Keratin

Answer 19

structural protein
forms fibers that reinforce epithelial cells
major protein in hair and horns

Question 20

Serum Albumin

Answer 20

transport protein

carries lipids

Question 21

Hemoglobin

Answer 21

transport protein

carries oxygen

Question 22

Transferrin

Answer 22

transport protein

carries iron

Question 23

Bacteriorhodopsin

Answer 23

transport protein
light-activated H+ pump
transports protons out of the cell (bacteria)

Question 24

Glucose Transporters

Answer 24

transport protein

shuttle glucose into and out of cells

Question 25

Calcium Pumps

Answer 25

transport protein | clears calcium ions from a muscle cell's cytosol after the ions have triggered a contraction

Question 26

Insulin

Answer 26

signal protein | controls glucose levels in the blood

Question 27

Netrin

Answer 27

signal protein | attracts growing nerve cell axons to specific locations in the developing spinal cord

Question 28

Nerve Growth Factor

Answer 28

signal protein | stimulates some types of nerve cells to grow axons

Question 29

Epidermal Growth Factor

Answer 29

signal protein | stimulates the growth and division of epithelial cells

Question 30

Ferritin

Answer 30

storage protein | binds to iron and stores it in the liver

Question 31

Ovalbumin

Answer 31

storage protein | stores amino acids in egg white for developing bird embryo

Question 32

Casein

Answer 32

storage protein | stores amino acids in milk for baby mammals

Question 33

Myosin

Answer 33

motor protein provides motive force for humans to move skeletal muscle cells

Question 34

Kinesin

Answer 34

motor protein | interacts with microtubules to move organelles around the cell

Question 35

Dynein

Answer 35

motor protein | enables eukaryotic cilia and flagella to beat

Question 36

Rhodopsin

Answer 36

receptor protein | detects light in the retina

Question 37

Acetylcholine Receptor

Answer 37

receptor protein | activated by acetylcholine released from a nerve ending

Question 38

Insulin Receptor

Answer 38

receptor protein | allows a cell to respond to insulin by taking up glucose

Question 39

Adrenergic Receptor

Answer 39

receptor protein | increases rate of heartbeat when it binds to epinephrine secreted by adrenal gland

Question 40

Lac Repressor

Answer 40

transcription regulator | silences genes in bacteria for enzymes that degrade lactose sugar

Question 41

DNA-binding Proteins

Answer 41

transcription regulator | act as genetic switches to control development in multicellular organisms

Question 42

Antifreeze Proteins

Answer 42

special-purpose protein | protect blood of Arctic/Antarctic fishes from freezing

Question 43

Green Fluorescent Protein

Answer 43

special-purpose protein | emits green light in jellyfish

Question 44

Monellin

Answer 44

special-purpose protein | provides sweet taste to an African plant

Question 45

Glue Proteins

Answer 45

special-purpose protein | secreted by mussels to attach to rocks