Cell Transport Unit 3 Flashcards
What is the chemical makeup of the plasma membrane?
PPS 4-11
A Phospholipid bilayer composed of proteins, carbohydrates, and cholesterol
Phospholipids are made out of a phosphate head, glycerol, and fatty acid tails
Why is the membrane described as selectively permeable or semipermeable?
The cell membrane is selectively-permeable membrane that allows only some substances and molecules to pass into or leave the cell.
All cells are surrounded by a selectively-permeable membrane. This membrane not only surrounds the cellular organelles but also acts as a barrier between the internal and the external environment. A cell membrane that is selectively permeable acts as a boundary or fence of the cell. It allows the molecules to pass through active or passive transport.
What can easily cross the plasma membrane?
PPS 16-24-1
Small molecules like H2 and O2
easily and water with the help of transport proteins
Non charged lipid molecules
Small polar molecules like water
How is the passage of passable molecules related to its chemical composition?
PPS 16-24-1
What does semipermeable mean?
Semipermeable means the allowing of certain substances to pass through it like solvents and some solutes
What is diffusion?
PPS 26, 37-42
It is the movement of molecules form an area of higher concentration to an area of lower concentration
Movement occurs along a concentration gradient
What is osmosis?
PPS 26, 37-42
It is the diffusion of water across selectively permeable membrane from a region of LOWER solute concentration to a HIGH solute concentration
For osmosis to occur the solute would not be able to pass through the membrane
Important to note*** water moves freely back and forth through semipermeable membrane
3 main types of osmosis:
Hypotonic
Hypertonic
Isotonic
What is hypotonic and its solute concentration?
PPS 39-42
Hypo rhymes with low soooo LOWWWW solute concentration
EXPENDING OF CELL
Swelling
What is hypertonic and its solute concentration?
PPS 39- 42
High solute ( salt ) concentration in cell
And low water concentration in cell
Cell shrinking
What is isotonic and its solute concentration?
PPS 39-42
Water doesn’t move because the conditions inside and outside are the SAME
STABLE
What is crenation?
PPS 37-47
the formation of abnormal cells as a result of water loss through osmosis
hypertonic causes crenation of shell basically for it to prune and shrink
OCCUR IN ANIMAL CELLS
What is turgor pressure?
PPS 37-47
the pressure that is exerted by the fluid like water against the cell wall
Expanding to point of bloat due to hypotonic process of tooo much water/fluid
What is lysis?
PPS 37-47
the breakdown of a cell caused by damage to its plasma membrane
What is plasmolysis?
PPS 37-47
OCCUR IN PLANT CELLS
It is defined as the process of contraction or shrinkage of the cell of a plant cell and is caused due to the loss of water in the cell.
What are aquaporins?
PPS 52
It is the water transport
It is a hydrophilic channel protein at cell membrane that allows the transfer of water to pass through the membrane
How cell transport work?
It is the movement of substances across the cell membrane either into or out of the cell.
Sometimes things just move through the phospholipid bilayer. Other times, substances need the assistance of a protein, like a channel protein or some other transmembrane protein, to cross the cell membrane.
What is diffusion?
PPS 53-
Spontaneous movement of a substance from one region to another often with a net movement from a region of high concentration to one of the low concentration
What is facilitated transport?
PPS 53-57
It is a type of PASSIVE transport of substances across a membrane with assistance of transmembrane carrier that does not require energy
What is active transport?
PPS 53-57
The movement of ions or molecules across a membrane in a single direction often against a gradient
This requires ENERGY usually in form of ATP and transport protein
What is endocytosis?
PPS 53-57
When the cells take in substances by vesicle formation in general term for any pinching off of the plasma membrane that results in the uptake of material from outside the cell
More types of endocytosis are:
Phagocytosis
Pinocytosis
Receptor mediated endocytosis
What is exocytosis?
PPS 53-57
When vesicles carry a specific molecule fuses with the membrane to release a substance
How are the previous terms related to anatomy and physiology?
PPS 53-57
What are the specific functions which concern the proteins in the membrane?
Proteins are used to
TRANSPORT PROTEINS substances from outside cell membrane to pass through to cell
CHANNEL PROTEINS have a hollow core
CARRIER PROTEINS alternate between two shapes moving a solute across the membrane during a shape change
AQUAPORINS allow the transfer of water through membrane
CORECEPTORS are proteins that work with another receptor to transfer
Materials across cell membrane
What are specific diseases that are caused by plasma membrane abnormalities as well as these proteins in the plasma membrane ?
Protein malnlutrition
General caloric deprivation
Kwashiorkor
How does the makeup of the plasma membrane concern the study of anatomy/physiology?
Handout :/?
What are receptor proteins?
PPS 83
It’s role is to bind molecules
They are shaped in a way that a specific molecule came bind to the receptor protein
IT RECEIVES MOLECULES