Chapter 6

Question 1

Plasma Membrane

Answer 1

The selectively permeable boundary that encloses the cell, separating its internal environment from the external environment

Question 2

Phospholipids

Answer 2

An amphipathic lipid molecule with a hydrophilic phosphate head and two hydrophobic fatty acid tails, the primary structural component of cell membranes

Question 3

Bilayer

Answer 3

A double layer of phospholipid molecules arranged with their hydrophobic tails facing inwards and their hydrophilic head facing outward towards the aqueous environment

Question 4

Membrane Fluidity

Answer 4

The property of the cell membrane that allows for movement flexibility, influenced temperature and lipid composition

Question 5

Integral membrane protein

Answer 5

A transmembrane protein that spans the entire lipid bilayer, with hydrophobic regions interacting the membrane interior

Question 6

Peripheral membrane protein

Answer 6

A protein that is loosely associated with the surface of the cell membrane, often bound to integral proteins or phospholipids

Question 7

Glycoproteins

Answer 7

A protein with one or more covalently attached carbohydrates

Question 8

Glycolipid

Answer 8

A lipid with one or kore covalently attached carbohydrates

Question 9

Cell-cell Recognition

Answer 9

The ability of a cell to distinguish one type of neighboring cell form another, often mediated by carbohydrates on the cell surface

Question 10

Concentration gradient

Answer 10

A difference in the concentration of substance across a distance

Question 11

Diffusion

Answer 11

The nest movement of substance from and area high concentration to an are of low concentration due to random molecular motion

Question 12

Simple Diffusion

Answer 12

The movement of a substance across a membrane without the help of membrane proteins

Question 13

Facilitated Diffusion

Answer 13

The movement of a substance across a membrane with the help of membrane transport proteins (channel or carrier proteins)

Question 14

Channel Protein

Answer 14

A transmembrane protein that forms a hydrophilic channel through the membrane, allowing specific ions or small polar molecules to pass

Question 15

Carrier Protein

Answer 15

A transmembrane protein that binds to a specific molecule, undergoes a conformational change, and transports the molecule cross the membranes

Question 16

Osmosis

Answer 16

The diffusion of water across a selectively permeable membrane from an rea of lower solute concentration to an area of higher concentration

Question 17

Hypertonic solution

Answer 17

A solution with a higher solute concentration compare to another solution

Question 18

Hypotonic Solution

Answer 18

A solution with a lower solute concentration compared to another solution

Question 19

Isotonic solution

Answer 19

A solution with an equal solute concentration compared yo another solution

Question 20

Turgid

Answer 20

Swollen or distended, typically referring to a plant cell in a hypotonic solution

Question 21

Flaccid

Answer 21

Limp or wilting, typically referring to a plant cell in a isotonic solution

Question 22

Plasmolysis

Answer 22

The concertation of the protoplast of plant cell as a result of water loss in a hypertonic solution

Question 23

Active Transport

Answer 23

The movement of a substance across a membrane against its concentration gradient, requiring energy input

Question 24

Membrane potential

Answer 24

The voltage (electrical potential difference) across a cells plasma membrane due to the unequal distribution of ions

Question 25

Electrochemical gradient

Answer 25

The combination of a concentration gradient and an electrical gradient that affects the movement of ions across a membrane

Question 26

Primary Active Transport

Answer 26

Active transport that directly uses a source of chemical energy (EX: ATP hydrolysis)to move a sub stance against its concentration gradient

Question 27

Proton pump

Answer 27

An active transport protein that move hydrogen ion s9Protons) across membrane, often using ATP as the energy source

Question 28

Sodium-Potassium pump

Answer 28

An active transport protein in animal cells that pumps sodium ions out of the cell and potassium ions int the cell using ATP

Question 29

Electrogenic pump

Answer 29

A transport protein that generates voltage across a membrane

Question 30

Secondary active transport

Answer 30

Active transport that uses energy store in the electrochemical gradient created by primary active transport to move another substance against its concentration gradient

Question 31

Cotransporter

Answer 31

A membrane protein that transports two or more different molecules across the membrane at the same time

Question 32

Symport

Answer 32

A cotransporter that moves two or more substances in the same direction across the membrane

Question 33

Antiport

Answer 33

A cotransporter that moves two or more substances in opposite directions across the membrane

Question 34

Bulk transport

Answer 34

The movement of large particles or large quantities of molecules across the cell membrane, typically involving the formation or fusion of membrane vesicles

Question 35

Vesicles

Answer 35

A small, membrane-bound sac in the cytoplasm

Question 36

Exocytosis

Answer 36

The process by which cells secrete large molecules by the fusion of vesicles with the plasma membrane

Question 37

Endocytosis

Answer 37

The process by which cells take in substance from the outside by forming new vesicles from the plasma membrane

Question 38

Phagocytosis

Answer 38

A type of endocytosis in which cell engulfs large particles or microorganisms (cellular eating)

Question 39

Pinocytosis

Answer 39

A type of endocytosis in which the cell engulfs extracellular fluid and dissolves solutes (cellular drinking)

Question 40

Receptor-mediated Endocytosis

Answer 40

A type of endocytosis in which specific molecules bund to receptor proteins on the cell surface, triggering the formation of a vesicle