Chapter 8: Dynamic Cells

Question 1

What are Phospholids?

Answer 1

Cell membranes primarily made of a double layer.

Question 2

What is a Hydrophilic (water loving)?

Answer 2

The phosphate head of the molecule.

Question 3

What is a Hydrophobic (water fearing)?

Answer 3

The lipid tail of the molecule.

Question 4

What is it called when head dissolves easily in water?

Answer 4

Hydrophilic

Question 5

What is it called when tail does NOT dissolves easily in water?

Answer 5

Hydrophobic

Question 6

What is a Phospholipid Bilayer?

Answer 6

2 layers of phospholipid molecules.

The bilayer gives the membrane flexibility and allows it to change shape.

Question 7

What forms a biological mosaic?

Answer 7

Carbohydrates, lipids, proteins

Question 8

What is the cell membrane function?

Answer 8

1. Biological Barrier (prevents many substances from entering a cell, i.e., viruses, ions, bacteria, salts, etc.)
2. Selective Filter (moves only certain substances across the membrane.)

Question 9

How are your cells semi-permeable?

Answer 9

1. Allows certain materials into the cell.

2. Moves wastes out of the cell.

Question 10

What is Selective Transport?

Answer 10

Movement across membranes.

Question 11

What is Brownian Motion?

Answer 11

It is when particles in a liquid or air are in constant, random motion.

Question 12

What is Equilibrium?

Answer 12

A state of balance when all the particles are equally divided.

Question 13

What is a Net Flow?

Answer 13

Overall division.

Question 14

What is Passive Transport?

Answer 14

It is the movement across cell membranes without an input of energy.

Question 15

What are the 2 reasons molecules move?

Answer 15

1. Brownian Motion

2. Concentration Gradient

Question 16

What are 3 Types of Passive Transport?

Answer 16

Diffusion, Osmosis, Facilitated Diffusion

Question 17

What is Diffusion?

Answer 17

The net movement of particles from an area of high concentration to an area of low concentration.

Question 18

Why does oxygen diffusing into the cell never reach equilibrium?

Answer 18

Your cells continually consuming oxygen for cellular respiration, therefore, making the concentration of oxygen inside the cell always lower than the concentration of oxygen outside the cell.

Question 19

What is Osmosis?

Answer 19

The diffusion of water molecules across a membrane where they are more highly concentrated to where they are less concentrated.

Question 20

What is a Hypotonic Solution?

Answer 20

Lower concentration of solute. Outside the cell (cell = hypertonic)

Water is more concentrated outside the cell and water will enter the cell (cell swells)

Question 21

What is a Hypertonic Solution?

Answer 21

Higher concentration of solute compared to the inside of the cell (cell = hypotonic)

Water is less concentrated outside the cell and water will leave the cell (cell shrinks)

Question 22

What is a Isotonic Solution?

Answer 22

Has the same solute concentration on both sides of the cell membrane. This means equilibrium has been reached. Equal amounts of water enters and leaves the cell. No net movement of water.

Question 23

What happens when a cell is placed into distilled water?

Answer 23

The cell is hypertonic the water moves into the cell, the cell may burst.

Question 24

What is turgor pressure?

Answer 24

Water pressure within plant cells that allows them to continue to be rigid.

Question 25

What happens when a cell is placed into strong salt water?

Answer 25

The solution is hypertonic and the water leaves the cell. The cell shrinks and may die (plasmolysis).

Question 26

What is plasmolysis?

Answer 26

When the cell membrane peels off the cell wall due to the loss of water which causes wilting.

Question 27

Why would drinking saltwater pose a problem?

Answer 27

Hypertonic solution outside cells would cause cells to lose water, shrink and die (dehydration).

Question 28

What is Facilitated Diffusion?

Answer 28

The use of transport proteins to help particles move across a cell membrane from an area of high concentration to an area of lower concentration.

Question 29

When transport proteins have 3-D shapes what does it make them?

Answer 29

It makes them highly selective, recognizing atoms or molecules by shape, size or charge.

Question 30

What is Active Transport?

Answer 30

When particles move up the concentration gradient from an area of low concentration to an high concentration. It needs an input of energy.

Question 31

What is Bulk Transport?

Answer 31

The use of vesicles to facilitate movement of substances that are too large to enter or exit the cell which is via transport proteins.

Question 32

What is Endocytosis?

Answer 32

When the cell membrane creates a pocket around the material to be transported, and then either pinches off as a vesicle or a vacuole.

Question 33

What is the difference among a vacuole and vesicle?

Answer 33

• Vesicle transports contents.

- Vacuole stores or keeps ingested material.

Question 34

What is Phagocytosis?

Answer 34

When cells “eat” by taking in large particles or other cells.

Question 35

What is Pinocytosis?

Answer 35

When cells “drink” by taking in droplets of fluid.

Question 36

What happens after a new vesicle enters the cytoplasm of a cell?

Answer 36

It fuses with a lysosome and the enzyme would digest the material.

Question 37

What is Exocytosis?

Answer 37

It is when it allows the materials kept in vesicles and vacuoles to exit or leave the cell. Also, the membrane of the vesicle or vacuole fuses with the membrane, and the stored content are released.

Question 38

What are the 3 examples of how semi-permeable membranes are utilized in technology and medical applications?

Answer 38

1. Water Purification - Reverse Osmosis
2. Kidney Dialysis
3. Controlled Delivery of Medications

Question 39

What are Liposomes?

Answer 39

Artificial vesicles which can safely move medications from one part of the body to another.

Question 40

What is the Surface-area-to-volume ratio?

Answer 40

The surface area of the cell which relates to its volume.