Chapter 3 — The Cell — Membrane, etc

Question 1

cell replication is the process by which

Answer 1

cells make two identical copies of themselves

Question 2

cell replication involves two processes:

Answer 2

mitosis & cytokinesis

Question 3

mitosis splits ___ into 2 daughter cells, while cytokinesis splits _______

Answer 3

DNA; cytoplasm

Question 4

definition of cell differentiation

Answer 4

process by which cells become functionally different from one another

Question 5

cell differentiation begins once a blastocyst reaches

Answer 5

critical mass

Question 6

during differentiation, three embryonic tissue types are formed

Answer 6

endoderm, mesoderm, ectoderm

Question 7

3 main functions of the cell membrane

Answer 7

barrier
cell-to-cell communication
binding to the extracellular matrix

Question 8

many cells bound to the extracellular matrix create

Answer 8

tissues

Question 9

the membrane is ________, only letting certain molecules in and out

Answer 9

semipermeable

Question 10

two two major structural components of the membrane

Answer 10

lipids and proteins

Question 11

most of the lipids forming the membrane are _______

Answer 11

phospholipids

Question 12

phospholipids are arranged in a ______

Answer 12

bilayer

Question 13

3 types of lipids used in the membrane’s structure

Answer 13

phospholipids
cholesterol
glycolipids

Question 14

lipid bilayer allows _______ molecules through, but not ________ molecules

Answer 14

lipid-soluble; water-soluble

Question 15

phospholipids are composed of a ________ and a ________

Answer 15

hydrophilic head and a hydrophobic tail

Question 16

phospholipid heads are hydrophilic because they must

Answer 16

attract materials from the aqueous mixtures in each compartment

Question 17

phospholipid tails are hydrophilic because they must

Answer 17

prevent water-soluble molecules (ions) from moving through

Question 18

an exception to the rule of thumb as far as movement through the lipid bilayer goes

Answer 18

actual water molecules can pass through, even though water-soluble molecules cannot

Question 19

phospholipids are ____-limiting, not letting _____ molecules through

Answer 19

size; large

Question 20

function of cholesterol in the membrane

Answer 20

provides structural stability, maintaining balance between membrane’s fluidity and rigidity

Question 21

functions (2) of glycolipids in the membrane

Answer 21

serve as ‘nametags’ labelling the cell

serve as attachment sites to the extracellular matrix

Question 22

glycolipids are ________ carbs

Answer 22

conjugated

Question 23

the function of proteins in the membrane depends on the protein’s _______

Answer 23

molecular structure

Question 24

3 main functions of proteins in the cell membrane

Answer 24

cell-to-cell adhesion
receptor sites for c.t.c. communication
transportation of molecules in or out of cell

Question 25

proteins used for c.t.c adhesion are called

Answer 25

desmosomes

Question 26

proteins used for transportation are called

Answer 26

Membrane Transport Proteins

Question 27

each MTP displays ______ and is _________, only moving molecules in one direction

Answer 27

specificity; unidirectional

Question 28

2 main types of MTPs

Answer 28

channel proteins

transporter proteins

Question 29

channel proteins participate in ______ ________

Answer 29

facilitated diffusion

Question 30

transporter proteins participate in ________ _______

Answer 30

active transport

Question 31

channel proteins that have no gate

Answer 31

leak channels

Question 32

2 types of gated channels

Answer 32

ligand-gated

voltage-gated

Question 33

_____ ______ channels require a molecule to ‘unlock’ the gate for another molecule’s passage through

Answer 33

ligand-gated

Question 34

the molecule that opens the ligand-gated channel is called the

Answer 34

ligand

Question 35

what opens a voltage-gated channel?

Answer 35

change of the inner membrane’s charge as ions enter

Question 36

which channel’s transportation can be likened to a line of dominos falling?

Answer 36

voltage-gated channels

Question 37

channel proteins move material ______ its gradient

Answer 37

with

Question 38

transporter proteins move material _______ its gradient

Answer 38

against

Question 39

example given of a ligand-gated channel

Answer 39

ACH-gated Na+ channel

Question 40

when a molecule binds to a transporter protein, it undergoes

Answer 40

conformational change

Question 41

example given of a transporter protein

Answer 41

Na+K+ pumps —Na+ is pumped out, K+ is pumped in

Question 42

bulk movement of material in or out of cell

Answer 42

exocytosis & endocytosis

Question 43

what type of transport is used in exocytosis & endocytosis?

Answer 43

a transporter protein (active transport)