Chapter 7

Question 1

What is selective permeability and what is it exhibited by?

Answer 1

Exhibited by the plasma membrane, allowing certain substances to pass through

Question 2

Ampipathic molecules

Answer 2

Molecules that possess both a hydrophobic and hydrophilic molecules

Question 3

What is the fluid mosaic model?

Answer 3

A model that displays the phospholipid bilayer as a mosaic of protein molecules bobbing on the bilayer

Question 4

Where is Steroid cholesterol found, and what does it do?

Answer 4

Wedged between phospholipid molecules in the plasma membrane of animal cells, with temperature affecting its fluidity

Question 5

How does temperature affect steroid cholesterol?

Answer 5

At high temperatures, it makes the membranes less fluid

Question 6

What are integral proteins?

Answer 6

Proteins that penetrate the hydrophobic interior of the lipid bilayer. Majority are transmembrane proteins

Question 7

Peripheral proteins

Answer 7

Appendages loosely bound to the surface of the membrane, often bound to the integral proteins

Question 8

What are the types of proteins on a plasma membrane? (6)

Answer 8

Transport
Enzymatic
Signal transduction
Cell to cell recognition
Intercellular joining
Attachment to the cytoskeleton and Extracellular matrix

Question 9

What are Transport proteins (4)

Answer 9

Spans the membrane and provides a hydrophilic channels across the membrane that is selective for a particular solute.
Some shuttle a substance by changing shape
Some use ATP actively pump substances
Hydrophilic

Question 10

Enzymatic proteins (2)

Answer 10

Enzymes with active site exposed to substances in the adjacent solution
Can form teams of enzymes with active to carry sequential steps of a metabolic pathway

Question 11

Signal transduction proteins (2)

Answer 11

Proteins with binding sit with a specific shape that fits the shape of chemical messengers like hormones

Messengers can change the shape of protein to relax the message

Question 12

Cell to cell recognition proteins

Answer 12

Serves as ID tags recognized by membrane proteins of other cells

Question 13

Intercellular joining proteins

Answer 13

Membrane proteins of adjacent cells hook together to form junctions

Question 14

Protein attachments to the cytoskeleton and Extracellular matrix

Answer 14

Binds to said substances to maintain cell shape, and stabilize location of certain membranes

Question 15

What are glycolipids?

Answer 15

Carbohydrates bound to lipids for cell to cell recognition

Question 16

Glycoproteins

Answer 16

Carbohydrates bonded to proteins

Question 17

What passes the phospholipids easily?

Answer 17

Hydrophobic/ Nonpolar molecules

Question 18

What are aquaporins?

Answer 18

A transport protein for water

Question 19

What are carrier proteins?

Answer 19

Proteins that hold onto molecules or ions and change shape in a way to transport said molecules

Question 20

What is diffusion?

Answer 20

Movement of particles of substances

Question 21

Dynamic equilibrium

Answer 21

Solute molecules continue to cross a membrane at equal rates in both directions

Question 22

What is tonicity and what does it depend on? (2)

Answer 22

Ability of a surrounding solution to cause a cell to gain or lose water

Depends on its concentration of solutes that cannot cross the membrane relative to that inside the cell

Question 23

What is an isotonic environment?

Answer 23

Equal amounts of nonpenetrating solutes in and outside the cell

No net movement

Question 24

Hypertonic (2)

Answer 24

More nonpenetrating solutes surrounding the cell

Cells lose water, shrivels, and dies

Question 25

Hypotonic

Answer 25

Less nonpenetrating solutes surrounding the cell Cell takes too much water, swells, and lyse

Question 26

What is osmoregulation, and what organisms use it?

Answer 26

Control of solute concentrations and water balance Used with organisms without a rigid cell walls to survive hypertonic and hypotonic environments

Question 27

What environment are organisms with cell walls in?

Answer 27

Hypotonic environment

Question 28

Turgid pressure

Answer 28

When a cel wall expands to its max capacity due to water intake, eating back pressure on the cell

Question 29

Turgid cell (2)

Answer 29

When a cell wall is firm The healthiest state for plant cellsb

Question 30

Flaccid state (2)

Answer 30

When a cell with a cell wall is in an isotonic environment No water entering the cell, making it limp

Question 31

Plasmolysis (2)

Answer 31

When a plant with a cell wall is in a hypertonic environment Loses water, shrivels, and membranes pull away from the cell wall

Question 32

Facilitated diffusion

Answer 32

Passive diffusion with the help of transport proteins

Question 33

Gated channels

Answer 33

Ion channels that open or close in response to stimuli like electrical

Question 34

ATP and active transport (2)

Answer 34

ATP transfers it’s terminal phosphate group directly to the transport protein Protein changes shape so that a molecule can bind to it

Question 35

Sodium potassium pump (2)

Answer 35

Pumps three sodium out and 2 potassium in to maintain a high potassium concentration and lower sodium concentration in the cell Maintains a negative charge

Question 36

Voltage (2)

Answer 36

Electrical potential energy/ separation of opposite charge Cytoplasmic side is negative in charge

Question 37

Membrane potential

Answer 37

Voltage across a membrane Ranges from -50 to -200 millivolts Acts as a battery to provide an energy source that affects transport Favors passive transport of cations into the cell

Question 38

Electrochemical gradient (3)

Answer 38

Two forces driving the diffusion of ions across the membrane The two forces include a chemical and electrical force Active transport may be necessary when electrical force is oppose the concentration

Question 39

Electrogenic pump

Answer 39

A transport protein that generates voltage across a membrane

Question 40

Proton pump and where is it found?

Answer 40

A protein that actively transports protons out of the cell Found in plants, fungi, bacteria

Question 41

What is Cotransport?

Answer 41

A transport protein, coupling, passive diffusion, followed by an active diffusion

Question 42

Exocytosis

Answer 42

Secretion of certain molecules by the fusion of vesicles with the plasma membrane

Question 43

Endocytosis (3)

Answer 43

Celtics in molecules and a particulate matter by forming new vesicles from the plasma membrane A small area of the membrane sinks inward to form a pocket The pocket than deepens punches and forms a vesicle

Question 44

Ligand

Answer 44

Any molecule that binds specifically to a receptor site on another molecule

Question 45

Phagocytosis

Answer 45

A cell engulfing, a particle by extending psuedopodia around it, and packages it within a food vacuole And then they just after the vacuole fuses with a lysosome

Question 46

Pinocytosis

Answer 46

I saw gulps and fluids into vesicles formed by infolding of a plasma membrane Nonspecific

Question 47

Receptor mediated Endocytosis

Answer 47

Type of Pinocytosis to acquire, book quantity of a specific substance