Cell/Plasma Membrane

Question 1

Basic structural framework

Answer 1

Lipid bilayer

Question 2

The lipid bilayer is made up of 3 layers from lipid molecules namely

Answer 2

Phospholipids
Cholesterol
Glycolipids

Question 3

What percentage does each layers 3 layers of the lipid bilayers cover? and what are those made of?

Answer 3

Phospholipids: 75%; phosphorus
Cholesterol: 20%; steroid with hydroxyl group (OH)
Glycolipids: 5%; carbohdyrate group

Question 4

What does amphipathic mean?

Answer 4

Amphipathic is having both sides of polar and nonpolar

Question 5

Differentiate polar and nonpolar

Answer 5

Polar is the phosphate-containing head which is hdrophilic, while nonpolar is the 2 long fatty acid tails which are hydrophobic

Question 6

Insterted among lipids in both layers of the membrane

Answer 6

Cholesterol molecule

Question 7

Is the cholesterol molecule strongly or weakly amphipathic?

Answer 7

Weakly amphipathic because cholesteril molecule is made up of fat which is hydrophobic

Question 8

This forms a polar head

Answer 8

glycolipid

Question 9

Nonpolar tails in glycolipids

Answer 9

fattty acids

Question 10

On which side do glycolipids appear?

Answer 10

On the side that faces the extracellular fluid

Question 11

2 classifications of membrane proteins

Answer 11

Integral proteins
Peripheral proteins

Question 12

Other term for integral proteins

Answer 12

Transmembrane protein

Question 13

Embedded into the lipid bilayer

Answer 13

Intergral proteins

Question 14

Span the entire lipid bilayer

Answer 14

Transmembrane protein

Question 15

Proteins with carbohydrate that protrude to the extracellular fluid

Answer 15

Glycoproteins

Question 16

Describe the composition of carbohydrate

Answer 16

Carbohydrates are oligosaccharides and chains of 2-60 monosaccharide

Question 17

Extensive sugary coat that are hydrophilic and attracts fluid

Answer 17

Glycocalyx

Question 18

Proteins that are not fully embedded in the membrane

Answer 18

Peripheral proteins

Question 19

Where are peripheral proteins attched?

Answer 19

To the polar heads of membrane lipids/ integral proteins

Question 20

Differentiate integral and peripheral proteins

Answer 20

Integral proteins are embedded into the lipid bilayer while peripheral proteins are not fully embedded in the membrane

Question 21

Pores/ holes that function as passage of ions

Answer 21

Ion channel

Question 22

Integral proteins that move polar substances from one side to another

Answer 22

Carriers/ Trasnportes

Question 23

Integral proteins that serve as cellular recognition sites

Answer 23

Receptors

Question 24

Receptors recognize and binds what specific types of molecules?

Answer 24

Ligands

Question 24

Integral proteins that catalyze specific chemical reaction

Answer 24

Enzymes

Question 24

These two often serve as cell-identity markers

Answer 24

Membrane glycoproteins and Glycolipids

Question 24

Integral proteins which anchor proteins in the plasma membrane of neighboring cells to another

Answer 24

Linkers

Question 25

These cell-identity markers enable cells to: a. Recognize other cells (same kind) during (1) b. Recognize and respond to (2) foreign cells

Answer 25

1. tissue formation 2. potentially dangerous

Question 26

5 General Functions of Peripheral Proteins a. (1) b. Anchor (2) c. Participate in mechanical activities (3) d. Change (4) in dividing e. Attach cell to one another

Answer 26

1. Support 2. integral proteins 3. movement of materials 4. cell shape

Question 27

Allows the lipid bilayer to self-seal when punctured

Answer 27

Membrane fluidity

Question 28

Membrane fluidity enables movement of membrane components responsible for ---

Answer 28

cellular process

Question 29

Permits passage of substances

Answer 29

Membrane permeability

Question 30

Membrane permeability criteria

Answer 30

1. permeable to non-polar 2. impermeable to large uncharged particle (solid substances) 3. slightly permeable to water, urea, waste products (amino acid)

Question 31

This is how easily proteins and lipids carry out their environment in the cell membrane

Answer 31

Membrane fluidity

Question 32

Differentiate membrane fluidity and membrane permeability in terms of the entry of substances

Answer 32

Membrane fluidity: What goes in to the cell, comes out of the cell Membrane permeablity: Only allows specific materials to enter and leave the cell

Question 33

Processes that transort materials in and out of cells

Answer 33

Passice Process Active Process

Question 34

Movement of substance that do not require cellular energy (ATP)

Answer 34

Passive Process

Question 35

Processes under passive process

Answer 35

Diffusion (Simple and Facilitated) Osmosis

Question 36

Movement of molecules/ions due to the molecule’s kinetic energy

Answer 36

Diffusion

Question 37

Where are the 2 classifications of membrne proteins (Integral & Peripheral) located?

Answer 37

Plasma

Question 38

Passive movement of a substance without the help of membrane transport protein

Answer 38

Simple diffusion

Question 39

Passive movement of a substance through the channels or carriers

Answer 39

Facilitated diffusion

Question 40

Differentiate simple and facilitated diffusion

Answer 40

Simplke diffusion is the passive movement of a substance without the help of membrane transport protein, while facilitated diffusion is the passive movement of a substance through the channels or carriers

Question 41

Passive movement of water molecules from lower concentration to higher concentration

Answer 41

Osmosis

Question 42

Types of active processes

Answer 42

Active transport Transport in vesicles (Endocytosis, Exocytosis, Transcytosis)

Question 43

Cell expands energy; carriers

Answer 43

Active transport

Question 44

Differentiate primary from secondary active transport

Answer 44

Primary active transport is when energy comes from hydrolysis of ATP while secondary active transport is when energy is supplied by Sodium or Hydrogen concentration gradient

Question 45

Breakdown of water to produce ATP / energy

Answer 45

hydrolysis

Question 46

3 processes in the transport of vesicles

Answer 46

Endocytosis Exocytosis Transcytosis

Question 47

Movement of substance into a cell in vesicle

Answer 47

Endocytosis

Question 48

Types of endocytosis

Answer 48

Bulk-phase endocytosis Phagocytosis Receptor-mediated endocytosis

Question 49

Ligand-receptors triggers infolding of a clathrin-coated pit that forms a vesicle containing ligands

Answer 49

Receptor-mediated endocytosis

Question 50

“Cell eating”; engulfing of pseudopods

Answer 50

Phagocytosis

Question 51

Example of a pseudopod

Answer 51

White blood cells

Question 52

“Cell drinking”; movement of extracellular fluid

Answer 52

Bulk-phase endocytosis

Question 53

Movement of substance out of the cell in secretory vesicles that fuse with the plasma membrane

Answer 53

Exocytosis

Question 54

Movement of substance as a result of endocytosis on one side and exocytosis on the opposite side

Answer 54

Transcytosis