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48 terms

The Cell membrane and Cellular Transport

STUDY
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What do all cells have
Cell Membrane(plasma membrane)
Cell membranes control what _____________ the cell to maintain an internal balance called ________
enters and exits
homostasis
What do cell membranes provide?
protection and support
What is structure of the cell membrane
Lipid bilayer
What are lipid bilayer made from
2 layer of phospholipids
Phosphate head is ______
polar
what does hydrophilic
water loving
Fatty Acid tails are ______
nonpolar
what does hydrophobic
water fearing
What are embedded in the membrane
Proteins
Phospholipids are the modified so that a _______(PO4-) replaces one of the three fatty acids normally found on a lipid. The addition of this group makes a _________________
Phosphate group,
polar head and 2 non polar tails
Fluid mosiac of the cell membrane
Molecules move freely in the membrane(fluid)
What do cell membranes have ____in them
pores(holes)
Selectively permeable
allows some molecules in and keep others out
What helps it be selective?
the structure
What are two types of cellular transport?
Passive and Active
Passive Transport
diffusion
In passive transport, do cells use energy or not
Cells do not use energy
In passive transport, molecules move _____
randomly
In passive transport, molecules spread out from an area of ____ concentration to an area of ____ concentration
high; low
high to low, fluids will ____
flow
What are four types of passive transport
simple diffusion
facilitated diffusion
osmosis
ion channels
diffusion
random movement of particles from an area of high con. to low con.
diffusion continues until what happens
equilibrium is reached
Facililated Diffusion
diffusion of specific particles through carrier proteins
what are carrier proteins
they select only certain molecules to cross the membrane
What do carrier proteins transport?
large or changed molecules
Osmosis(simple diffusion)
diffusion of water through a a selectively permeable
Hypotoncic
the solution has a lower concentration of solute and a higher concentration of water than inside of the cell
Whats the result of hypotoncic
water moves from the solution to inside the cell. cell swells and bursts open(cytolysis)
Hypertonic
the solution has a higher and lowerr concentration of h20 than inside of the cell
Whats the result of the hypertonic cell
water moves from inside the cell into the solution. the cell shrinks. c plasmolysis
Isotonic
the concentration of solutes in the solution is equal to the concentration of solutes inside of the cell
Whats the result of being isotonic
water moves equally in both directions and the cell remains the same size(dynamic equilibrium)
How do bacteria and plants cells deal with osmosis pressure
they have cell walls that prevent them from over-expanding. In Plants the pressure exerted on the cell wall is called turgour pressure
How do protist like paracieum deal with osmosis pressure
has contractile vacules that collect water flowing in and pump it out
Ion channels
membrane proteins similar to carrier proteins transport ions from high to low concentration
How do the ions get through
because they cant pass through the nonpolar part of the lipid bilayer so they are shielded by protein channel
What type of energy does active transport use
ATP
does active tranport require energy
yes
Active transport
movement from a low area of concentration to an area of high concentration
what are 3 types of active transport
Protein pumps
Endocytosis
Exocytosis
Protein pumps
transport proteins that require energy to do work
endocytosis
taking bulky material into a cell
-cell membrane in-folds around particle
-forms vesicle/vacuole around particles
what are two types of endocytosis
phagocytosis
pinocytosis
phagocytosis
cell eating
pinocytosis
cell drinking
Exocytosis
forces materials out of cell in bulk
-membrane surrounding the material fuses with cell membrane
-cell changes shape