Membrane Transport

Question 1

Movement of particles/solute across/through membrane barrier

Answer 1

Membrane transport

Question 2

Type of membrane transport that does not use energy; molecules are moving from high to low concentration

Answer 2

Passive transport

Question 3

A model that describes the plasma membrane structure as a mosaic of components - including phospholipids, cholesterol, proteins, and carbohydrates; membranes are constucted from lipids and proteins

Answer 3

Fluid mosaic model

Question 4

They formulated the fluid mosaic model in 1972

Answer 4

Singer & Nicolson

Question 5

Formed when carbohydrates present on the plasma membrane’s exterior surface are attached to proteins

Answer 5

Glycoproteins

Question 6

Formed when carbohydrates present on the plasma membrane’s exterior surface are attached to lipids

Answer 6

Glycolipids

Question 7

“Water-loving” areas of the molecules

Answer 7

Hydrophilic

Question 8

Water-hating molecules; tend to be non-polar

Answer 8

Hydrophobic

Question 9

A molecule with a positively or negatively charged area, and an uncharged or non-polar area; “dual-loving”

Answer 9

Amphiphilic

Question 10

Characteristics of the phospholipid bilayaer (fluid mosaic model):

Answer 10

Hydrophilic head, hydrophobic tail

Question 11

Two protein classes in the fluid mosaic model:

Answer 11

Peripheral, integral

Question 12

The structure forming unit of the fluid mosaic model

Answer 12

Lipid bilayer

Question 13

Proteins (in the fluid mosaic model) may be:

Answer 13

• absorbed to membrane surface
• span through the membrane

Question 14

Proteins that integrate completely into the membrane structure, and their hydrophobic membrane-spanning regions interact with the phospholipid bilayer’s hydrophobic region

Answer 14

Integral proteins or integrins

Question 15

Proteins that are on the membranes’ exterior and interior surfaces, attached either to integral proteins or to phospholipids; may serve as enzymes along with integrins, as structural attachments for the cytoskeleton’s fibers, as part of the cell’s recognition sites

Answer 15

Peripheral proteins

Question 16

Components of the plasma membrane:

Answer 16

• Phospholipid
• Integral proteins
• Peripheral proteins
• Carbohydrates

Question 17

The main membrane fabric of the plasma membrane

Answer 17

Phospholipid

Question 18

Attached between phospholipids and between the two phospholipid layers

Answer 18

Cholesterol

Question 19

Embedded within the phospholipid layer; may or may not penetrate through both layers

Answer 19

Integral proteins

Question 20

On the phospholipid bilayer’s inner or outer surface; not embedded within the phospholipids

Answer 20

Peripheral proteins

Question 21

Generally attached to proteins on the outside membrane layer

Answer 21

Carbohydrates

Question 22

Because the plasma membranes are ________, they allow some substances to pass through, but not others.

Answer 22

selectively permeable

Question 23

A physical space in which there is a single substance concentration range has a ________.

Answer 23

concentration gradient

Question 24

A passive process of transport where a single substance moves from a high concentration to a low concentration area until the concentration is equal across a space; transport of substances/solute; net movement of anything

Answer 24

Diffusion

Question 25

A transport where materials diffuse across the plasma membrane with the help of membranous proteins

Answer 25

Facilitated transport or facilitated diffusion

Question 26

Membranous proteins that aid in facilitated transport:

Answer 26

* Channels/guted channels * transporters/transport proteins

Question 27

Integral proteins involved in facilitated transport

Answer 27

Transport proteins

Question 28

Proteins that have hydrophilic domains exposed to the intracellular and extracellular fluids; have a hydrophilic channel through their core that provides a hydrated opening through the membrane layers

Answer 28

Channel proteins

Question 29

Channel proteins that allow water to pass through the membrane at a very high rate

Answer 29

Aquaporins

Question 30

A type of proteins embedded in the plasma membrane; binds a substance and thus triggers a change of its own shape, moving he bound molecule from the cell's outside to its interior

Answer 30

Carrier proteins

Question 31

The movement of water through a semipermeable membrane according to the water's concentration gradient across the membrane, which is inversely proportional to the solutes' concentration; concentration of solute equal on both sides of the membrane; the solute cannot pass through the selectively permeable membrane

Answer 31

Osmosis

Question 32

Describes how an extracellular solution can change a cell's volume by affecting osmosis; capability of the solution to modify the volume of the cells

Answer 32

Tonicity

Question 33

Describes the solution's total solute concentration

Answer 33

Osmolarity

Question 34

The extracellular fluid has lower osmolarity than the fluid inside the cell, and water enters the cell; low concentration of solute

Answer 34

Hypotonic

Question 35

The extracellular fluid having a higher osmolarity than the cell's cytoplasm; the fluid contains less water than the cell; higher concentration of solute

Answer 35

Hypertonic

Question 36

The extracellular fluid has the same osmolarity as the cell; equal concentration of solute

Answer 36

Isotonic

Question 37

Changes the shape of the real blood cells in hypertonic, isotonic, and hypotonic solutions

Answer 37

Osmotic pressure

Question 38

The ________ within a plant cell depends on the tonicity of the solution.

Answer 38

Turgor pressure

Question 39

A kind of transport where mechanisms require the cell's energy, usually in the form of ATP; against the concentration gradient

Answer 39

Active transport

Question 40

Pushes chemicals from low to high concentrations in active transport

Answer 40

ATP

Question 41

Measure of free energy; combined effects of gradient concentration and electrical gradient

Answer 41

Electrochemical gradient

Question 42

Move potassium and sodium ions across plasma membrane

Answer 42

Sodium-potassium pump

Question 43

Work against lectrochemical gradient

Answer 43

Active transport mechanisms or pumps

Question 44

Moves ions across a membrane and creates a difference in charge across that membrane

Answer 44

Primary active transport

Question 45

Does not directly require ATP; the movement of material due to the electrochemical gradient established by the primary active gradient

Answer 45

Secondary active transport

Question 46

Carrier proteins or pumps that facilitate movement in active transport

Answer 46

Transporters

Question 47

Three types of protein transporters:

Answer 47

* Uniporter (carries one ion/molecule) * Symporter (2 ions/molecules) * Antiporter (2 ions/molecules, but in diff. directions)

Question 48

A kind of transport, where moving big particles or fragments of cells takes place

Answer 48

Bulk transport

Question 49

A type of active transport that moves particles, such as large molecules, parts of cells, and even whole cells, into a cell

Answer 49

Endocytosis

Question 50

The condition of "cell eating"; the process by which a cell takes in large particles; big molecules are brought inside; form vacuole

Answer 50

Phagocytosis

Question 51

A variation of endocytosis discovered by Warren Lewis in 1929; termed as "cell driking"; process that takes in molecules, including water, which the cell needs; large amounts of liquid; form vesicles

Answer 51

Pinocytosis

Question 52

A process that uses a coating protein (caveolin) on the plasma membrane's cytoplasmic side; brings small molecules into the cell and transports them through the cell for their release on the other side (transcytosis)

Answer 52

Potocytosis

Question 53

A process that brings specific substances that are normally in the extracellular fluid and also allows other substances to gain entry into the cell at the same site; removes low density liporotein from the blood

Answer 53

Receptor-mediated endocytosis

Question 54

Reverse process of moving material into a cell; taking out; a vesicle migrates the plasma membrane, binds, and releases its contents to the outside of the cell

Answer 54

Exocytosis