Chapter 4: Cell

Question 1

The major components of the cell

Answer 1

• plasma membrane
• cytoplasm
• nucleus

Question 2

Plasma membrane

Answer 2

the selectively permeable barrier separating internal contents from the external environment

Question 3

Cytoplasm

Answer 3

cellular contents between the plasma membrane and nucleus; includes:
- cytosol (fluid of the cytoplasm)
- inclusions
- organelles

Question 4

Nucleus

Answer 4

the largest structure in the cell that’s enclosed by a nuclear envelope; contains genetic material (DNA); also contains a nucleus

Question 5

Organelles

Answer 5

“little organs”; complex organized structures within cells

Question 6

Membrane-bound organelles

Answer 6

• endoplasmic reticulum, golgi apparatus, lysosomes, peroxisomes, mitochondria

Question 7

Non-membrane-bound organelles

Answer 7

• ribosomes
• cytoskeleton
• centrosome
• proteasomes

Question 8

Cell functions

Answer 8

• maintain integrity and shape of the cell
• obtain nutrients and form chemical building blocks
• dispose of wastes
• some are capable of cell division

Question 9

Mitochondria

Answer 9

“powerhouse of the cell’; complete digestion of fuel molecules to synthesize ATP

Question 10

Golgi apparatus

Answer 10

“warehouse of the cell”; modification, packaging, and sorting proteins; formation of secretory vesicles and lysosomes

Question 11

Rough endoplasmic reticulum

Answer 11

peroxisomes produced here; protein production by ribosomes, inserted into ER

Question 12

Smooth endoplasmic reticulum

Answer 12

• synthesis, transport, and storage of lipids
• carbohydrate metabolism
• detoxification of drugs and poisons

Question 13

Bound ribosomes

Answer 13

attached to the external surface of the ER membrane; synthesize proteins for export, become part of plasma membrane, or serve as enzymes in lysosomes

Question 14

Free ribosomes

Answer 14

suspend within cytosol; all other proteins within cell synthesized here

Question 15

Lysosomes

Answer 15

contain digestive enzymes formed by golgi; participate in the digestion of unneeded substances

Question 16

Passive transport

Answer 16

do not require energy; depend on substances moving down the concentration gradient; two types:
1- diffusion
2- osmosis

Question 17

Diffusion

Answer 17

movement of solutes; end result: equal distribution

Question 18

Osmosis

Answer 18

movement of water; end result: equal concentration

Question 19

Active transport

Answer 19

requires energy; movement of a solute against its concentration gradient

Question 20

Types of active transport

Answer 20

• ion pumps
• Na+/K+ pumps

Question 21

Ion pumps

Answer 21

maintain internal concentrations of ions

Question 22

Na+/K+ pumps

Answer 22

continuously exports Na+ out of the cell and moves K+ into the cell

Question 23

Exocytosis

Answer 23

large substances secreted from the cell

Question 24

Endocytosis

Answer 24

cellular uptake of large substances from external environment

Question 25

Phagocytosis

Answer 25

“cellular eating”; occurs when a cell engulfs a large particle external to the cell

Question 26

Pinocytosis

Answer 26

“cellular drinking”; internalization of droplets of interstitial fluid containing dissolved solutes

Question 27

Isotonic solutions

Answer 27

both cytosol and solution have same relative concentration of solutes

Question 28

Hypotonic solution

Answer 28

gains water through osmosis; extracellular fluid has a lower concentration of solutes, higher concentration of water than in cytosol

Question 29

Hypertonic solution

Answer 29

loses water through osmosis; extracellular fluid has a higher concentration of solutes than cytosol, a lower concentration of water than in cytosol