(Fluid mosaic model) Cell membrane models Flashcards
Describe the structure of the fluid mosaic model
A double layer of phospholipids and cholesterol molecules and proteins
Explain how the fluid mosaic model is suited to wards the transport of materials through the cell membrane
Because it is semipermeable and allows for some substances to pass through tiny paws in the membrane and prevent other molecules from doing so
What is the difference between hydrophobic and hydrophilic and how does it relate to the transport across the cell membrane
Hydrophilic means they are water loving where is hydrophobic means water hating
Hydrophilic substances travelled through the phospholipid bilayer
Hydro phobic travel through channel protein
Why is it called the “fluid mosaic model”
Fluid because the molecules are always changing position a mosaic because it its composed of many types off of molecules
Where is the cholesterol in the fluid mosaic model
Embedded in the phospholipid bilayer
Why is the cell membrane semipermeable
So only some ions and molecules can pass through the cell wall
What is the difference between passive and active processes
Passive
No energy needed
Molecules move along the concentration gradient
Remember some going down a slide “wee this is fun”
Active
Energy needed
Molecules move against concentration gradient remember someone walking up a slide “this is going to be hard work”
What is the function of the cell membrane
To maintain a barrier and regulate what comes in and out
What is simple diffusion, osmosis, facilitated transport,
Simple diffusion (passive): the spread of particles that are evenly distributed over the available space towards the are off higher concentration
Osmosis: is diffusion off water across a deferentially permeable membrane
Facilitated (could be either passive or active): proteins in the cell allow molecules to be transported across the membrane
Protein channels: provide pathway for hydrophobic particles across the cells membrane large molecules are too big to fit
Carrier protein only open on on side and will only bind to A particular molecule
What is vesicular transport
The movement of substances across the cell membrane and in membrane sacks called vesicles it is an active process
Endocytosis:the transport into the cell by vescular transport this folds around a droplet of liquid or a particle until it is completely enclosed the vesical formed then pinches of and is suspended into the cytoplasm
Exocytosis: The transport outside of a cell through a vesical formed by the Gumbuya predators the continent of the vesical are then pushed out into the extracellular fluid
What is a concentration gradient
When when concentration of particles are higher in one area than another
Describe in detail the Active process of Exocytosis of solid materials
Waste/ newly formed proteins in cell passing to the cytoplasm
Processes of Phagocytosis (solid passing from cell)
Molecules accumulate in the cell, enveloped by a vesicle from the Golgi apparatus
Vesicle migrates to the cell membrane
Fuses with the cell wall inside the cell
The outer cell membrane breaks down allowing the contents to be released into the cell
This process requires energy in the form of ATP
The cell membrane is commonly referred to as the Fluid Mosaic Model. Explain why it is referred to as this and how its structure affects its functions
Fluid due to the ever changing position of the molecules
Mosaic due to the large array of molecules that it is comprised of
Bilayer of Hydrophilic heads and Hydrophobic tail interacting to create a membrane
Lipid soluble molecules can pass through easy via diffusion
Creates a physical barrier
Channel and carriers proteins within the cell membrane
Helps with passive and active transport of larger/ non lipid soluble molecules
Proteins on the outer membrane surface are receptors
Act as binding site for specific molecules
Fatty acids and steroids pass with ease through the phospholipid bilayer, however water takes a different passage. Describe 2 functions of the phospholipid bilayer and describe the cause of why water takes a different passage?
Physical barrier
Regulate material
Sensitivity - detect changes via receptors
Steroids and fatty acids are similar substances to the cell membrane thus can pass through easily
Water can not pass through hydrophobic membrane/ non lipid soluble
