Lesson 3

Question 1

organelles

Answer 1

internal structures of a cell that carry out specialized metabolic tasks

Question 2

non-membranous organelles

Answer 2

do not have a membrane surrounding them
- cytoskeleton, microvilli, centrioles, cilia, ribosomes, and proteasomes

Question 3

membranous organelles

Answer 3

surrounded by a membrane
- nucleus, ER (rough and smooth), golgi complex, lysosomes, peroxisomes, and mitochondria

Question 4

cytosol

Answer 4

clear, viscus, watery, colloid within the cell
- contains enzymes and other proteins, amino acids, ATP, electrolytes, dissolved gases, and metabolic waste

Question 5

cytoskeleton

Answer 5

a network of protein filaments and cylinders
- structural support, determines cell shape, organizes cell contents
- directs movement of materials within the cell, contributes to movements of the cell as a whole

Question 6

microfilaments

Answer 6

smallest
- made of actin
- form terminal web aka membrane skeleton
- 6 nm thick

Question 7

intermediate filaments

Answer 7

• within skin cells
• 8 to 10 nm thick
• made of keratin
• give cell shape and resist stress

Question 8

microtubules

Answer 8

largest
- consists of protofilaments made of tubulin
- maintain cell shape
- hold organelles
- act as railroad tracks for walking motor proteins
- make axonemes of cilia and flagella
- form mitotic spindle
- 25 nm thick

Question 9

______ provide mechanical strength by anchoring cytoskeleton to plasma membrane proteins

Answer 9

microfilaments

Question 10

______ interact with cytosolic proteins to adjust liquidity of cytosol.

Answer 10

microfilaments

Question 11

these filaments are the most stable and durable of all cytoskeletal elements

Answer 11

intermediate filaments

Question 12

intermediate filament functions (4)

Answer 12

1. provide mechanical strength/durability to the cell
2. maintains shape
3. stabilizes organelle position
4. stabilized cells onto substrates/other cells

Question 13

_____ _____ in the superficial layers of the skin are intermediate filaments

Answer 13

keratin fibers

Question 14

microtubule functions (5)

Answer 14

1. attaches to the centrosome
2. provides strength to the cell/stabilizes organelle positions
3. changes in microtubules change cell shape
4. can be used as a “highway system” in the cell for motor proteins
5. form spindle apparatus

Question 15

motor proteins called _____ and _____ can use ATP energy to move organelles along microtubules

Answer 15

kinesin, dynein

Question 16

microvilli

Answer 16

extensions of the plasma membrane that serve to increase surface area

Question 17

the core of microvilli is composed of _____

Answer 17

microfilaments

Question 18

on some adaptive cells, they are very dense and appear as a fringe called the _____ _____

Answer 18

brush border

Question 19

cilia

Answer 19

small hair like processes composed of microtubules, can be motile or not

Question 20

where can motile cilia be found?

Answer 20

respiratory tract, uterine tubes, ventricles of the brain, ducts of testes

Question 21

centriole

Answer 21

a short, cylindrical assembly of microtubules arranged in nine groups of three microtubules each

Question 22

ribosomes

Answer 22

small granules of protein and RNA responsible for producing proteins

Question 23

proteasomes

Answer 23

hollow, cylindrical organelles that dispose of surplus proteins, contain emzymes

Question 24

rough ER

Answer 24

synthesizes phospholipids and proteins

Question 25

smooth ER

Answer 25

synthesizes lipids and steroids

Question 26

golgi complex

Answer 26

a system of membranous cisterns that synthesizes carbohydrates and modifies newly synthesized proteins

Question 27

lysosomes

Answer 27

package of enzymes bound by a membrane

Question 28

primary lysosome

Answer 28

formed by the Golgi complex, enzymes inside are inactive

Question 29

secondary lysosome

Answer 29

formed when the primary lysosome fuses to an endosome or fuses with damaged organelles, activating the enzymes inside

Question 30

autophagy

Answer 30

digestion of cell’s surplus organelles

Question 31

autolysis

Answer 31

digestion of a cell by itself, “cell suicide”

Question 32

Tay-Sachs disease

Answer 32

rare genetic disease
lack of lysosomal enzyme causes a buildup or lipids in brain cells leading to death of those cells
- infantile for of disease leads to death of the child by age 4

Question 33

peroxisomes

Answer 33

resemble lysosomes but contain different enzymes and are produced by ER and mitochondria and from other peroxisomes

Question 34

what is the enzyme within peroxisomes?

Answer 34

catalase, breaks down hydrogen peroxide to water and oxygen