Chapter 3.3-Cell transport and Homeostasis

Question 0

Transport Proteins

Answer 0

Substances in the cell membrane that help large molecules, hydrophilic molecules, and charged ions get across
Channel and Carrier
Part of Facilitated Diffusion

Used to help with: 
Structural support
Recognition
Communication
Transport

Question 1

Diffusion

Answer 1

The movement of a substance across a membrane, due to a difference in concentration, without any help from other molecules
Passive Transport
Substances that can diffuse through the membrane are generally very small hydrophobic molecules such as oxygen and carbon dioxide

Question 2

Facilitated Diffusion

Answer 2

Diffusion with the help of transport protiens

Type of Passive transport for large, or hydrophilic molecules, or charged ions

Question 3

Channel Proteins

Answer 3

Form pores or tiny holes in membrane allows water.

Allows and small ions to pass through without touching the hydrophobic tails on the inside of the membrane

Question 4

Carrier Protiens

Answer 4

Bind with specific ions or molecules
Change shape
They carry the ions or molecules across the membrane
Bond and drag molecules through lipid bilayer and release them on the opposite side

Question 5

Passive Transport

Answer 5

Occurs when substances pass through the cell membrane without any energy input from the cell
Happens when things go from high concentration to low concentration
Diffusion
Osmosis
Facilitated Diffusion

Question 6

Active Transport

Answer 6

Occurs when energy is needed for a substance to move across the cell membrane
Goes from low to high concentration
Energy is from energy carrying molecules called ATP
May involve transport proteins

Question 7

Sodium Potassium Pump

Answer 7

Active transport
Sodium (Na) ions pumped out, potassium (K) ions pumped in
Both go from lower to higher concentration
Sodium ions bind with a carrier protein
Carrier protein receives a phosphate group from ATP
When ATP loses a phosphate group, energy is released
Carrier protein changes shape, pumps the three sodium ions out of the cell
Potassium ions bind to the carrier protein

Question 8

Vesicle Transport

Answer 8

Helps very large molecules cross membrane
Active transport
Endotysis
Exotysis

Question 9

Endocytosis

Answer 9

Vesicle transport/active transport
Moves substances into cell
Plasma membrane completely engulfs the substance, a vesicle pinches off from the membrane, and the vesicle carries the substance into the cell

Question 10

Exocytosis

Answer 10

Vesicles Transport/Active transport
Moves substance out of the cell
Vesicle containing the substance moves through the cytoplasm to the cell membrane, the vesicle membrane fuses with the cell membrane, and the substance is released outside the cell

Question 11

Homeostasis

Answer 11

The process of maintaining stable conditions inside a cell or an entire organism
Stable state must be maintained for cell to function normally
Concentration of substances must be kept within a certain range
Requires constant adjustments because conditions inside and outside cell are constantly changing
Processes like Active and Passive Transport help

Question 12

Equilibrium

Answer 12

Caused by diffusion

State of balance, in which everything is equal, both inside and outside or cell

Question 13

Hypotonic

Answer 13

Water comes into the cell
Cell gets bigger, may burst
If it bursts, called Cytolysis

Question 14

Aquaporins

Answer 14

Water Channels

Protein pores used during osmosis

Question 15

Hypertonic

Answer 15

Water hoes out of the cell
Cell gets smaller
When it shrivels, called plasmolysis

Question 16

Isotonic

Answer 16

Equal amounts entering and leaving cell

Cell stays the same size

Question 17

Pinocytosis

Answer 17

Most common form of endocytosis
Takes in dissolved molecules as a vesicle
Forms invagination, pinches off, goes into cell
Called cell drinking
Liquid

Question 18

Receptor Mediated Endocytosis

Answer 18

Have receptors that take in certain molecules and make vesicles out of that

Question 19

Phagocytosis

Answer 19

When cell takes in entire cell, such as bacteria or food

Called cell eating

Question 20

Plasma Membrane

Answer 20

Made of lipid bilayer of phospholipids (double layer)
Hydrophobic molecules pass easily
Hydrophilic do not

Protective Barrier
Regulate transport in and out of cell (selectively permeable)
Allow cell recognition
Provide anchoring sites for filaments of cytoskeleton
Provide a binding site for enzymes
Interlocking surfaces bind cells together (junctions)
Contains the cytoplasm (fluid in the cell)

Question 21

Phospholipids

Answer 21

Make up cell membrane
Contains two fatty acid chains that are non polar
Polar heads are hydrophilic (water loving)
Non polar tails are hydrophobic (water fearing)
Makes membrane selective in what crosses

Question 22

Solubility

Answer 22

Materials that are soluble in lipids can pass through the membrane easily
Solute-substance dissolved in another substance

Question 23

Cytolysis

Answer 23

Hypotonic solution

Cell bursts

Question 24

Plasmolysis

Answer 24

Hypertonic solution

Cell shrivels

Question 25

Solvent

Answer 25

Substance in which another substance is dissolved

Forms solution

Question 26

Contractile Vacuole

Answer 26

Membrane bound organelle that collects water and then expels it to the exterior of the cell
Helps maintain equilibrium in the cell

Question 27

Concentration Gradient

Answer 27

The way in which the diffusion moves

Question 28

Ion channel

Answer 28

Channel in which ions move through the membrane

Question 29

Turgidy

Answer 29

Turgidy of cells changes in different solutions
In hypotonic solutions, gets more turgid, pressured
In hypertonic solutions, gets less turgid, pressured