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CH3 Movement of substances Across Plasma membrane - Coggle Diagram
CH3 Movement of substances Across Plasma membrane
3.1 STRUCTURE
3.1.1 Justify the necessity
to carry out living processes
disposed waste from metabolic processes
3.1.2 components of plasma membrane & function
(fluid mosaic model)
protein molecules floats within the phospholipid bilayer
phospholipid molecule
:
polar head
(hydrophillic) - attracted to water, face extracelular fluid
nonpolar tail
(hydrophobic) - repels water, faces the cytoplasm
types protein molecules :
with canals/channels = channel protein
function as carriers = carrier protein
proteins + lipids with carbohydrate chain:
glycoprotein
,
glycolipid
act as receptors to hormones : insulin
stabilize membrane by forming hydrogen bond with water
antigens for cell identification
cholestrol molecules
(between phospholipid molecules)
function: makes phospholipid bilayer stronger, flexible, less permeable to water-soluble substances : ions
3.1.4 Permeability
selectively permeable membrane
only allows free movement of certain molecules across it, prevent or limit movement of other substances
3.2 CONCEPT
3.2.1 Characteristics of substances by aspects
factor :
molecule size
polar molecule
-ionic charge
small molecule /,& ion :
polar : water
nonpolar : O2, Co2
-ion : Na^+
Charged and polarized molecules dissolve in water while uncharged molecules dissolve in lipids. The lipid tails in the cell membrane prevent charged and polarized molecules from diffusing through the cell membrane.
large molecule
: glucose, amino acid
nonpolar molecule
: fatty acids, glycerol, fat soluble vit. (ADEK), steroid compounds
3.2.3 Type of movement + examples
PASSIVE TRANSPORT
simple diffusion
area of high concentration to an area of low concentration
move down concentration gradient until dynamic equilibrium is achieved
w/wo presence of membrane
:
nonpolar molecule
(lipid soluble molecules : fatty acid, glycerol, O2, CO2) diffuse through phospholipid bilayer
Osmosis
(ONLY WATER)
net movement from area of high water potential to low
randomly
through a
selectively permeable membrane
: same in phospholipid bilayer
facilitated diffusion
(FAT-INSOLUBLE : ions, large molecule)
with aid of transport protein : carrier/channel protein
:green_cross: energy - move down concentration gradient until dynamic equilibrium is achieved
channel:
form canals for small-size solutes, ions
have specific internal characteristics - allow specific ions through
carrier:
have specific sites that change shape to bind with specific molecule
-returns to original shape after
: glucose when extracellular concentration is higher than in cytoplasm
ACTIVE TRANSPORT
characteristics
movement against concentration gradient
:check: energy from ATP through respiration
specific carrier (pumps) with specific sites
has receptors to bind with ATP, change shape when attached to phosphate group
results in
accumulation / excretion of molecules in cell
: sodium-potassium pump - sodium ion to extracellular, potassium ions into cells
: proton pump (eoithelial cells lining in stomach) - causes acidity due to accumulation of hydrogen ion & acid production