Membranes- Chapter 5

Question 1

Phospholipid Bilayer

Answer 1

Two layers of phospholipids forming cell membranes.

Question 2

Fluid Mosaic Model

Answer 2

Proteins float in lipid bilayer like boats

Question 3

Transmembrane Proteins

Answer 3

Integral proteins spanning the lipid bilayer (embedded)

Question 4

Peripheral Membrane Proteins

Answer 4

Proteins attached to membrane surface

Question 5

Glycoproteins

Answer 5

Proteins with carbohydrate chains on cell surface

Question 6

Glycolipids

Answer 6

Lipids with carbohydrate chains on cell surface

Question 7

Transmission Electron Microscope

Answer 7

Microscope for studying membrane layers

Question 8

Scanning Electron Microscope

Answer 8

Microscope for studying membrane surfaces

Question 9

Phosphate Group

Answer 9

Polar, hydrophillic part of phospholipid

Question 10

Fatty acids

Answer 10

Nonpolor, hyddrophobic components of phospholipids

Question 11

Hydrogen bonding

Answer 11

Holds phospholipid layers together in membranes

Question 12

Saturated Fatty Acids

Answer 12

Decrease membrane fluidity compared to unsaturated

Question 13

Sterols

Answer 13

Lipids like cholesterol affecting membrane fluidity

Question 14

Aquaporins

Answer 14

Proteins factilitating water transport across membranes

Question 15

Passive Transport

Answer 15

Movement of molecules without energy input

Question 16

Simple diffusion

Answer 16

Nonpolar molecules move across memebrane freely

Question 17

Facilitated diffusion

Answer 17

Transport through proteins for larger molecules

Question 18

Ion channels

Answer 18

Proteins allowing ion pasage across membranes

Question 19

Osmosis

Answer 19

Water movement toward higher solute concentration

Question 20

Hypertonic solution

Answer 20

Higher solute concentration

Question 21

Hypotonic Solution

Answer 21

Lower solute concentration

Question 22

Isotonic Solutions

Answer 22

Same concentration

Question 23

Active Transport

Answer 23

Energy-requiring movement against concentration gradient.

Question 24

Sodium-Potassium Pump

Answer 24

Moves Na⁺ out and K⁺ into cells.

Question 25

Coupled Transport

Answer 25

Energy from one molecule aids another’s transport.

Question 26

Endocytosis

Answer 26

Process of taking substances into the cell.

Question 27

Exocytosis

Answer 27

Process of expelling substances from the cell.

Question 28

Familial Hypercholesterolemia

Answer 28

Genetic disease causing cholesterol accumulation.

Question 29

Functions of membrane proteins

Answer 29

• Transporters
• Enzymes
• Cell-surface receptors
• Cell-surface identity markers
• Cell-to-cell adhesion proteins
• Attachments to the cytoskeleton

Question 30

b-barrel

Answer 30

Cylinder of B sheets in the protein secondary structure

Question 31

Channel proteins

Answer 31

Hydrophillic when open

Question 32

Carrier proteins (passive)

Answer 32

Bind specifically to molecules they assists

Question 33

Gated channels

Answer 33

Open or close in response to stimuli

Question 34

Carrier proteins (active)

Answer 34

Highly selective

Question 35

Uniporters

Answer 35

Move one molecule at a time

Question 36

Symporters

Answer 36

Move two molecules in same direction

Question 37

Antiporters

Answer 37

Move two molecules in opposite directions

Question 38

Symporter (Coupled)

Answer 38

Example: Glucose–Na⁺ symporter captures energy from Na⁺ diffusion to move glucose against its concentration gradient.

Question 39

Countertransport

Answer 39

Moves materials in opposite directions

Question 40

Phagocytosis

Answer 40

Cell takes in matter

Question 41

Pinocytosis

Answer 41

Cell takes in fluid

Question 42

Receptor-mediated endocytosis

Answer 42

Specific molecules are taken in after binding to a receptor