Cells and Their Environment

Question 1

movement of substances across the cell membrane either into or out of the cell

Answer 1

Cellular Transport

Question 2

Components of Cell Membrane

Answer 2

• phospholipid bilayer
• transport protein

Question 3

allows certain molecules pass through and prevents other molecules from crossing

Answer 3

Semi-permeable membrane

Question 4

move easily (in & out) the cell membrane

Answer 4

small uncharged molecules

Question 5

move freely in the interior of the membrane

Answer 5

lipid-soluble substances

Question 6

do not cross lipid membranes easily unless specific transport mechanisms are present

Answer 6

water-soluble substances

Question 7

cannot pass through the membrane because of strong electrical charges

Answer 7

ions

Question 8

cell’s energy chief

Answer 8

Adenosine Triphosphate (ATP)

Question 9

Processes Involved in Moving Materials Across the Cell Membrane

Answer 9

• Passive Transport
• Active Transport
• Bulk Movement

Question 10

the movement of a substance across a cell membrane without the input of the cell’s energy

Answer 10

Passive Transport

Question 11

Types of Passive Transport

Answer 11

• Simple Diffusion
• Facilitated Diffusion
• Osmosis

Question 12

most common form of passive transport

Answer 12

Simple Diffusion

Question 13

the random movement of molecules from an area of higher concentration (more molecules) to an area of lower concentration (fewer molecules)

Answer 13

Simple Diffusion

Question 14

Factors Affecting the Rate of the Diffusion

Answer 14

• temperature
• size of the molecules

Question 15

the difference between the concentration of a particular molecule in one area and its concentration in an adjacent area

Answer 15

Concentration Gradient

Question 16

Process of Facilitated Transport

Answer 16

1. Protein binds with the molecule (glucose)
2. Shape of protein changes based on the size of molecule
3. Molecule moves across membrane

Question 17

help molecules or ions enter or leave the cell and are usually transport proteins

Answer 17

channels

Question 18

difference between simple diffusion and facilitated diffusion

Answer 18

In simple diffusion, the substance passes between the phospholipids; in facilitated diffusion, there are specialized membrane channels.

Question 19

the diffusion of water across a semi-permeable membrane

Answer 19

Osmosis

Question 20

often involves the movement of water
water moves from solutions with higher water (lower solute) concentrations to solutions with lower water (higher solute) concentrations

Answer 20

Osmosis

Question 21

the concentration of solutes outside is higher than it is inside the cell, the water diffuses out of the cell

Answer 21

Hypertonic Solution

Question 22

shrinkage of red blood cell

Answer 22

Crenation

Question 23

shrinkage of bacterial cell

Answer 23

Plasmolysis

Question 24

the concentration of solute is lower outside the cell than inside, and water moves into the cell

Answer 24

Hypotonic Solution

Question 25

the concentration of solutes inside is very high than it is outside the cell

Answer 25

Very Hypotonic Solution

Question 26

bursting of red blood cell

Answer 26

Hemolysis

Question 27

bursting of bacterial cell

Answer 27

Plamoptysis

Question 28

the concentration of solutes outside the cell equals the concentration of solutes inside the cell

Answer 28

Isotonic Solution

Question 29

solution where osmosis do not occur

Answer 29

Isotonic Solution

Question 30

the movement of a substance across a cell membrane requiring the use of energy; usually occurs against a concentration gradient

Answer 30

Active Transport

Question 31

Importance of Active Transport

Answer 31

a. Contraction of muscles
b. Transmission of nerve impulses
c. Absorption of nutrients
d. Plants: enables the roots to absorb nutrients from the soil
e. one of the several ways that an organism maintains homeostasis

Question 32

process used by a cell to transport large molecules, such as polysaccharides or proteins, across its membrane

Answer 32

Bulk Movement

Question 33

2 Types of Bulk Movement

Answer 33

a. Exocytosis
b. Endocytosis

Question 34

cell discharges material from inside to outside

Answer 34

Exocytosis

Question 35

movement of large material from outside to inside

Answer 35

Endocytosis

Question 36

Process of Endocytosis

Answer 36

• Plasma membrane surrounds material
• Edges of membrane meet
• Membranes fuse to form vesicle

Question 37

cell engulfs a food particle or other solid substance, rather than a liquid

Answer 37

Phagocytocis

Question 38

Forms of Endocytosis

Answer 38

a. Phagocytosis (cell eating)
b. Pinocytosis (cell drinking)

Question 39

organisms that engulf and destroy bacteria

Answer 39

Phagocyte (WBC/leukocyte) & amoebas

Question 40

the cell membrane encloses a droplet of fluid and its solutes and brings the droplet into the cell

Answer 40

Pinocytosis

Question 41

the maintenance of a stable set of internal conditions within an organism

Answer 41

Homeostasis