biology:cell membrane and transport

Question 1

why are cells so small

Answer 1

to sufficiently regulate traffic in and out of cell

as cell line increases the surface area increases at a slower rate

Question 2

fluid mosaic model of the cell

Answer 2

selectively permeable
homeostasis maintained by constant movement across membrane
phospholipid bilayer
proteins dispersed throughout like mosaic tiles
fluid proteins and lipids move in membrane
hydrophobic barrier keeps hydrophilic molecules in or out
some proteins help transport molecules across member

Question 3

cholesterol molecules

Answer 3

temperature buffers

prevent too much fluidity or rigidity

Question 4

glycolipids/glycoproteins

Answer 4

attached membrane

work as a markers for cell to cell recognition

Question 5

selectively permeable

Answer 5

allows some molecules that are 
small uncharged polar molecules 
hydrophobic molecules 
lipid soluble molecules 
blocks other molecules:
large polar molecules 
ions

Question 6

proteins allow substances into the cell

Answer 6

1. Channel and transport proteins

let’s large polar hydrophilic molecules and ions through

Question 7

aquaporins

Answer 7

channel proteins that allows water through

Question 8

cell wall

Answer 8

structural boundary
permeability barrier
in plants made of cellulose
external to cell membrane
prokaryotes of fungi also have

Question 9

passive transport or diffusion

Answer 9

movement of nonpolar, hydrophobic molecules
no ATP needed
utilizes concentration gradient substances diffuse from high to low
primary role in import of resources and export of wastes

Question 10

facilitated diffusion

Answer 10

diffusion of charged and polar molecules through channel or carrier proteins in plamsa membrane
faster than simple diffusion

Question 11

osmosis

Answer 11

diffusion of water molecules from a hypotonic to hypertonic solution

Question 12

hypertonic solution

Answer 12

higher concentration of solutes

Question 13

hypotonic solution

Answer 13

lower concentration of solutes

Question 14

isotonic

Answer 14

equal concentration of solutes

Question 15

turgor pressure

Answer 15

large pressure caused by water entering cells with a cell wall

Question 16

Plasmolysis

Answer 16

cell collapse caused by water leaving the cell

Question 17

animal cell in hypotonic

Answer 17

lysed

Question 18

animal cell in isotonic solution

Answer 18

normal

Question 19

animal cell in the hypertonic solution

Answer 19

shriveled

Question 20

plant cell in hypotonic solution

Answer 20

turgid

Question 21

plant cell in isotonic solution

Answer 21

flaccid

Question 22

Plant cell in hypertonic solution

Answer 22

plasmolyzed

Question 23

active transport

Answer 23

proteins need energy to move molecules or ions
against concentration gradient
used to establish and maintain concentration gradient

Question 24

Exocytosis

Answer 24

transport vesicles fuse with plasma membrane and secrete large macromolecules outside of cell
used when cell produces substances for export
requires ATP

Question 25

endocytosis

Answer 25

captures large molecule outside cell
plasma membrane merges to engulf it forming new vesicle from plasma
requires ATP

Question 26

three kinds of endocytosis

Answer 26

phagocytosis
Pinocytosis
receptor-mediated endocytosis

Question 27

phagocytosis

Answer 27

cellular eating of undisolved material

Question 28

pincytosis

Answer 28

cellular drinking of dissolved substances

plasma membrane folds and word and forms vesicles

Question 29

receptor mediated endocytosis

Answer 29

extracellular molecules bind to specific receptors
occurs in coated pit region of plasma membrane
pit’s, receptors, and specific molecules called a ligands fold inward
vesicle forms