Interactions between Cells and Extracellular Environment
What are the 3 types of Passive Transport? https://www.youtube.com/watch?v=-aGYytZ7K7M
1. simple diffusion 2. facilitated diffusion 3. osmosis (water movement)
What percentage of extracellular fluid exists as Interstitial Fluid and Plasma outside of the cells?
33%
What percentage of intracellular fluid exists as water inside cells?
67%
What is the electrochemical gradient?
A combination of movement from the outside of the cell to the inside of a cell due to the charge of a molecule and the concentration gradient.
What type of transport is known as "bulk" transport that allows molecules and ions to move in and out of cell in vesicles?
Vesicular Transport
What mV causes the sodium-ion channel to open?
-55mV
What membrane potential is maintained by the sodium-potassium pump?
-70mv
What are two types of channels are used in Passive facilitated transport? https://www.youtube.com/watch?v=-aGYytZ7K7term-9M
1) Channel Proteins 2) Voltage-Gated channels ( chemical)
What are the 4 main components of the extracellular matrix?
1) Collagen Fibers 2) Elastin Fibers 3) Glycoproteins 4) Proteoglycans
What are the two types of gradients involved in transport?
1) Concentration gradient 2) Electrochemical gradient
What are the two types of transporters are involved in Secondary Active Transport (refer to the previous question).
1) Cotransporters 2) Antiporters
What are the two main types of transport through the cell membrane?
1) Passive Transport 2) Active Transport
What are the 2 main types of Active transport?
1) Primary Active Transport (direct ATP use) 2) Secondary Active Transport
Give two examples of Secondary Active Transport
1) Sodium-Glucose Symporter (Symporter) : Uses Na+ flowing down its concentration gradient to transport glucose AGAINST its concentration gradient. 2) Sodium-Calcium Exchanger (Antiporter): Where there is an exchange, Na+ is moving down its concentration gradient into the cell and Ca+ is moving against its concentration gradient out of the cell.
What are the two types of Vesicular Transport?
1. Endocytosis (into) 2. Exocytosis (out of)
What is type of molecule used to transport 3 molecules of Na outside of the cell wall where there is a higher concentration of Na?
A phosphate molecule from ATP which contains energy.
What can cells use the electrochemical gradient as?
A source of energy *The desire for Na molecules to move to the inside of a cell due to their charge and due to the concentration gradient.
What is required to move molecules against their concentration gradient?
ATP
What does the high concentration of Na on the outside of the cell prepare the cell to do?
Allow the cell to be charged so that when it is triggered the Na molecules rush in to give the cell energy.
What does the energy from the phosphate broken off of the ATP molecule cause the channel to do?
Change shape and open on the other side to allow the 3 Na molecules to be released on the outside of the cell.
What two types of proteins allow molecules to pass through to ensure they do not get stuck within the hydrophobic part of the cell membrane and are specific to different molecules? https://www.youtube.com/watch?v=8HlVy__J8XA Does this require energy?
Channel proteins ( Ex. Aquaporins) Carrier Proteins No (passive transport)
If the concentration of water is higher inside of the cell than outside of the cell it is considered ______________________.
Hypertonic
If the concentration of water is higher outside of the cell than inside of the cell it is considered _____________________.
Hypotonic
What side of the cell membrane typically has a low concentration of Na+ molecules?
Inside.
What is the state that water concentrations are always seeking? What organ(s) are essential for this process to take place?
Isotonic Kidneys
What does the pumping of 3 Na molecules out and 2 K molecules in allow the cell to achieve?
Its resting membrane potential.
Give an example of Primary Active Transport
Na+/K+ pump
What is the typical electrochemical arrangement (positive/negative) within most cells in our body such as brain cells?
Negative charge on the inside, positive charge on the outside.
Which of the two types of transport DOES NOT use ATP?
Passive transport
What type of transport uses the potential energy of the Na+ concentration on the outside of the cell and the electrochemical gradient to pump glucose against its concentration gradient?
Secondary Active Transport
What is the process by which energy from Primary Active Transport is used?
Secondary Active Transport.
What is (simple) diffusion?
The movement of non-polar molecules from an area of high concentration to an area of low concentration through the phospholipid bilayer of a cell.
How does blood travel from our closed circulatory system into our cells?
Through the interstitial fluid.
After releasing to Na molecules into the outside of the cell, what does the channel protein except?
Two K molecules
What is facilitated diffusion? Give an example.
When molecules or ions move down their concentration gradient using carrier proteins. Potassium Ion channels- K+ builds up due to the Sodium-Potassium pump and the channels open up to let K+ move down its concentration gradient out of the cell.
