Ch. 2

Question 1

Molecules in Water(3)

Answer 1

1. Hydrophilic
2. Hydrophobic
3. Amphipathic

Question 2

Hydrophilic

Answer 2

Water loving molecules that are easily coated and transported in water because they dissolve

Question 3

Hydrophobic

Answer 3

Water hating molecules do NOT dissolve in water and are NOT easily transported.

They separate from water

Question 4

Hydrophilic types

Answer 4

Polar molecules

Question 5

Hydrophobic types

Answer 5

Non polar molecules
Lipids
Proteins
Amino acids

Question 6

Amphipathic

Answer 6

Consists of 2 regions: one polar and one non-polar

Question 7

Phospholipid bilayer

Answer 7

Layered form of amphipathic molecule

Question 8

Cell membrane

Answer 8

Is a phospholipid bilayer containing many different molecular components, including proteins and cholesterol, some with carbohydrate groups attached

Question 9

Plasma membrane

Answer 9

Cell structure that defines the internal and external environments of the cell

Question 10

Proteins of Plasma Membrane (2)

Answer 10

1. Integral

2. Peripheral

Question 11

Integral Protein

Answer 11

Span the length of the membrane

Question 12

Peripheral Protein

Answer 12

Proteins found only on the inside or outside of the cell

Question 13

List the Types of Membrane Proteins (6)

Answer 13

Ion channel
Receptor
Linker
Transporter
Enzyme
Cell identity marker

Question 14

Ion Channel (integral)

Answer 14

Allows specific ions to pass through the plasma membrane

• the conformation of the channel has an opening that allows passage into the cell

Question 15

Receptors (integral)

Answer 15

Involved in cellular communication and control

• cell regulation and signaling
• bind specific molecules called ligand which causes a change in conformation that results in an internal response in the cell

Question 16

Transporter (lntegral)

Answer 16

Transports matter across the membrane

- molecules bind to the protein and modify its conformation which allows the substance to enter the cell

Question 17

Enzyme (integral and peripheral)

Answer 17

Catalyzes a chemical reaction inside or outside the cell depending on which side the binding site is facing

Question 18

Linker (integral and peripheral)

Answer 18

Anchors filaments inside and outside the plasma membrane, providing structural stability and shape for the cell

Question 19

Cell Identity Marker (integral)

Answer 19

A glycoproteins

Used in cell identification and communication

Question 20

Type of Cell Junctions

Answer 20

Anchoring
Tight junction
Gap junction

Question 21

What are membrane junctions?

Answer 21

Specialized connections between adjacent cells

Involved specific proteins

Question 22

3 Main Types of Membrane Junctions

Answer 22

Desmosome
Tight junction
Gap junction

Question 23

Desmosome

Answer 23

Fibrous proteins that are synthesized by each cell extended out to the adjacent cell and LINK together

The cell membrane DO NOT TOUCH, allowing ECF to flow between connected cells

Holds cells in position

Question 24

Where are Desmosome found?

Answer 24

Located primarily in the epithelium cells and occasionally in muscle cells

Question 25

Tight junctions

Answer 25

Membrane proteins in both cells link tightly together Prevent the movement of ECF BETWEEN THE CELLS

Question 26

Gap junctions

Answer 26

Ion Channels extend from each cell and link together across the extracellular space Membranes of the cells DO NOT TOUCH, only the ion channels Ions can flow from one cell to another A form of electrical communication between cells

Question 27

Where are gap junctions found?

Answer 27

Located in muscle and nervous tissues Allows for coordination of cells of the heart muscle

Question 28

Membrane Transport

Answer 28

The movement of substances across a membrane

Question 29

Diffusion

Answer 29

The movement of a substance across a membrane down its concentration gradient Diffusion ceases when equilibrium is reached across the membrane

Question 30

Types of Diffusion

Answer 30

Simple diffusion Facilitated diffusion Carrier mediated

Question 31

Simple diffusion

Answer 31

The substance can pass through the membrane without the help of a membrane protein Occurs primarily with non polar molecules

Question 32

Examples of Simple Diffusion

Answer 32

Water Gasses Solids Lipid soluble vitamins

Question 33

Facilitated Diffusion

Answer 33

Requires transport membrane proteins or ion channel for the movement of polar substances across the membrane

Question 34

Examples of facilitated diffusion

Answer 34

Occurs with Ions and polar molecules such as glucose, amino acids, and proteins

Question 35

Channel mediated diffusion

Answer 35

An ion channel allows the substance to cross the membrane Controls the diffusion of extracellular sodium into the cells and intercellular potassium out of cells

Question 36

Types of Ion Channels

Answer 36

Passive/leakage | Gated

Question 37

Passive/ leakage channel

Answer 37

Channel protein that is always open

Question 38

Gated channel

Answer 38

The confirmation of the channel protein has a “gate” that can change its shape and open or close the channel

Question 39

Carrier mediated channel

Answer 39

A transport protein in the membrane binds the substance being transported Results in a change in transport protein conformation and move substances into or out of the cell

Question 40

Example of carrier mediated diffusion

Answer 40

Glucose