A&P Chap 1-3 Flashcards
Extracellular fluid (ECF) includes…?
- Interstitial fluid
- blood plasma
- cerebrospinal fluid
What does Extracellular fluid (ECF) do?
Dissolves and transports substances in the body.
What does interstitial fluid consist of? List five.
A water solvent containing:
- glucose
- salt
- fatty acids
- minerals e.g. calcium, magnesium, potassium
- cell waste products
What is cerebrospinal fluid?
Fluid surrounding nervous system organs.
What is Intracellular fluid?
The fluid contained within cells
What are the four functions of the plasma membrane (aka cell membrane?)
- Physical barrier: encloses the cell, separating the cytoplasm from the extracellular fluid.
- Determines which substances enter or exit the cell.
- Communication: plasma membrane proteins interact with specific chemical messengers and relay messages to the cell interior
- Cell recognition: cell surface carbohydrates allow cells to recognize each other
What are two types of membrane proteins?
Integral proteins and peripheral proteins
Where are integral proteins and peripheral proteins located on the plasma membrane respectively?
Integral proteins - firmly embedded in the lipid bilayer
Peripheral proteins - anchored to the membrane or to other proteins.
What are the two regions of integral proteins?
Hydrophobic and hydrophilic regions
What is the function of integral proteins?
Transport proteins (channels and carriers), enzymes, or receptors.
Where are peripheral proteins found?
They are attached loosely to integral proteins or have a hydrophobic region that anchors them into the membrane.
What are the key functions of peripheral proteins?
- Help support the membrane from its cytoplasmic side.
- Functions as enzymes
- Cell-to-cell connections
- Act as motor proteins for shape change during cell division and muscle contractions
What are glycocalyx and its function?
A surface layer that covers the cell membrane of many bacteria, epithelial cells, or other cells. It is made up of proteoglycans, glycoproteins, and glycolipids. This acts as a barrier for a cell from its surroundings and provides protection. It helps in maintaining the integrity of cells.
What is the process of Passive Transport?
Substances cross the plasma membrane without any energy input from the cell (kinetic energy is used instead.) Substances move from high to low concentration (down the concentration gradient).
What is the process of Active Transport?
The cells provide the metabolic energy (ATP) needed to move substances across the membrane. Substances can move from low to high concentration (against the concentration gradient).
What are the 3 types of passive transport across the plasma membrane?
Simple diffusion facilitated diffusion and osmosis.
What are the 3 factors of the diffusion process?
- Concentration
- Molecular size
- Temperature
Explain the process of simple diffusion.
Substances diffuse directly through the lipid bilayer, often small nonpolar molecules that readily dissolve in lipids. E.g. gasses like oxygen and co2, steroid hormones, and fatty acids. It is passive diffusion.
What are the two criteria that determine how easily a substance will pass by simple diffusion through a plasma membrane?
- lipid solubility
- size
Explain the process of the facilitated diffusion
Transported substance either
1. binds to carrier proteins in the membrane and is carried across or,
2. move through water-filled channel proteins. E.g. glucose, amino acids, and ions such as sodium and potassium.
What is osmosis
The diffusion of a solvent, e.g. water through a specific channel protein or through the lipid bilayer. A passive transport.
What is osmolarity
The total concentration of all solute particles in a solution
What is osmotic pressure?
An inward pressure due to the tendency of water to be “pulled” into a cell with higher osmolarities
What is tonicity?
Refers to the ability of a solution to change the shape of cells by altering the cells’ internal water volume.
What happens to a cell in isotonic solutions?
Cells retain their normal size and shape.
What happens to a cell in hypertonic solutions?
The higher concentration of nonpenetrating solution causes cells to lose water and shrivel.
What happens to a cell in hypotonic solutions?
The more dilute solution causes cells to take on the water until they become bloated and burst.
Difference between primary and secondary active transport.
In primary active transport, the energy is derived directly from the breakdown of ATP. In the secondary active transport, the energy is derived secondarily from energy that has been stored in the form of ionic concentration differences between the two sides of a membrane.
Name some major primary active transport systems.
Calcium, hydrogen, and sodium-potassium pump.
How does the sodium-potassium pump work?
- Pumps 3 sodium (Na) ion out of the cell and 2 potassium (K) ion back into the cell
- Located in all plasma membranes, especially active in excitable cells
- Needs ATP to move. Essential for functions of muscle and nerve tissues.
- The pump protein enzyme: Na K ATPase.
What do symporters do?
The movement of two molecules in the same direction through a protein channel.
What do antiporters do?
Movement of two molecules in the opposite direction through a protein channel.