Chapter 6 lipids terms Flashcards
Diffusion
Movement that are not water molecules; spontaneous
What type of movement is diffusion
Moves from lots of molecules to little amount of molecules
Osmosis
Water movement
What is the concentration gradient
Moving from on gradient to another; difference in solute concentration
Moving with gradient
Lots of molecules to little amount of molecules;no energy needed
Moving against gradient
Little amount of molecules to lots of molecules; takes energy
Passive transport
-facilitated diffusion
- moving with gradient
- no energy need
what are the 2 types of passive transport
- channel- protein moves pathway
- carrier- protein physically grabs onto whatever is moving across membrane
plasma membrane
separates cells interior; keep damaging materials out
what does the plasma membrane house
phospholipids
permeability
ability for things to go through
low permeability
cannot pass thru easily
high permeability
can pass thru easily
is the plasma membrane permeable
somewhat permeable
phospholipid bilayer
- found in plasma membrane
- double layer
- head and tail
what is the structure of the phospholipid head
hydrophilic and polar; faces outwards
what is the structure of the phospholipid tail
hydrophobic and nonpolar; faces inwards
how does he phospholipid bilayer form
when put into water
what is the main difference between lipids compared to the other macromolecules
they are nonpolar and hydrophobic
what are the 3 main types of lipids
- steroids
- fats
- phospholipids
what is a steroid
a hormone; cholesterol
what is the structure of steroids
clunky ring structure and the tail comes off ring structure along with functional groups
what are fats
energy storage
what is the structure of fats
- fatty acids linked to glycerol
- held together via ester linkages
- dehydration reactions
what are phospholipids
long hydro carbon chains that function to control molecular traffic
what is the structure of phospholipids
- phosphate group
- polar group
- make up cell membrane
why are phospholipids considered amphipathic
they have both hydrophobic and hydrophilic regions
why is tail structure important
determines how membrane behaves
- kink
- no kink
- length
how does temperature affect membrane fluidity
- warmer temp= membranes more fluid
- lower temp= membranes become less fluid
rigid
low movement; can easliy get through
what is the main function of cholesterol
prevents membranes from being too liquid
how do phospholpids move
laterally and can sometimes flip flop
what aspects determine how phospholipids move
rigid or tightly packed together
why do membranes move so much
cells need to exchange materials and need movement for this
why do molecules move across membranes
create equilibrium
do channel and carrier transport move with or against gradient
with gradient
how does water like to move
more water (less solute) to less water (more solute)
net transport
want amount of solute entering and exiting to be the same; cancel out
isotonic (animals)
- at equilibrium
- no net difference in water
- amount of water coming in=amount of water going out
hypotonic (animals)
- water moves into cell
- more water coming into cell than going out
- cell will swell
hypertonic (animals)
- water moves out of cell
- loose water and shrink/shrivel
what state of tonicity do plants prefer
hypotonic because the pressure gives structural support to the plant
hypotonic (plants)
completely filed with water
isotonic (plants)
loose pressure because water leaving and going is the same
hypertonic (plants)
- no water coming in
- solute building up
- cell membrane starts to pull away from cell wall
channel proteins
- help to move larger, polar molecules
- very selective
- hydrophilic and hydrophobic conditions
why is ion movement important
important for cellular respiration
what is the concentration of ion movement
electrochemical gradients
flaccid
limp; low cell pressure
turgid
swollen; high cell pressure
pumps
sodium and potassium; against concentration gradients
osmolarity
concentration of dissolved solutes in a solution
saturated fats
undisrupted chain
- animals fats
- exist at room temperature -
unsaturated fats
kink=double chain
- exist as liquid at room temperature
aquaporin
type of channel protein that facilitates osmosis
fluid mosaic model
proteins are inserted into the lipid bilayer making membrane a fluid, dynamic mosaic of phospholipids and proteins
