Chapter 3 Cells Flashcards
What are the three main parts of a cell?
Plasma Membrane, Cytoplasm and Nucleus
What is Cytoplasm and what does it consist of?
Consists of all the cellular contents between the plasma membrane and nucleus. Contains Cytosol and Organelles.
What is Cytosol and Organelles?
Cytosol is the liquid portion of the Cytoplasm, is Water and dissolved solutes. Is Intracellular Fluid.
Organelles are little organs with different structures and function within the cell.
What is the Nucleus?
The Control center of cells. Contains the genes and controls structure and function of cellular activities.
What is characteristics of Plasma Membrane?
Plasma Membrane consists of three type of lipids, and two types of proteins. Has the lipid bilayer. Phospholipids, cholesterol and glycolipids make up membrane, Integral proteins extend into the bilayer, Peripheral proteins loosely attached to the exterior or interior of surface.
Describe the permeability of the plasma membrane.
Plasma Membrane has selective permeability to water and non polar(lipid soluble) molecules. NOT permeable to Ions and large uncharged polar molecules. However Ion channels are formed through Integral proteins.
What is a solute vs solvent and what is a concentration?
A material dissolved in a fluid is called a solute, the fluid in which it is dissolved in is the solvent. The amount of solute (“stuff”) in a solution is its concentration.
What is Passive Process vs Active Process?
Passive process a substance moves down its concentration gradient without using energy - diffusion and Osmosis. Active process uses cellular energy (ATP) to push pass against the concentration gradient.
What is simple diffusion vs facilitated diffusion and types?
Simple diffusion - substances diffuses through lipid bilayer from high to low concentration.
Facilitated diffusion is a passive process that uses an integral membrane protein as either a channel or a carrier. As a channel substances moved down the gradient via their specific channel, as a carrier the substance binds on one side of membrane and releases on the other side after changing shape.
*The Hormone insulin does this for glucose.
What is Osmosis?
A passive process where water moves by osmosis from area of higher WATER concentration to lower WATER concentration. Passes through lipid bilayer and uses integral proteins that function as water channels.
What is Osmotic Pressure?
The pressure exerted on a a plasma membrane by a solution where its particles can’t pass through the membrane.
What is Isotonic vs Hypotonic vs Hypertonic Solutions and their relation to Red Blood Cells.
Isotonic - a solution where cells maintain shape and volume. Concentration of solutes are same on both sides.
Hypotonic - a solution that has lower concentration of solutes and higher concentration of water. Vs RBC water enters blood cells quicker than it leaves causing expansion and rupture/burst = Hemolysis.
Hypertonic - a solution that has higher concentration of solutes an low water. Vs RBC moves out of cells by osmosis faster than they enter causing them to shrink. = Crenation
What is Active Transport?
An Active process that cellular energy is used to transport substances across the membrane AGAINST the concentration gradient. ATP is used to change the shape of carrier protein which moves substances across gradient.
Describe the Sodium-Potassium Pump.
The most important active transport pump.
It pushes Sodium Ions (Na+) out of cells and brings in Potassium Ions (K+).
Doing this the pump maintains a low concentration of Na+ in the cytosol by pumping Na+ against the Na+ concentration gradient out of the cell into extracellular fluid.
The pump moves K+ into cell against the K+ gradient.
Na+ slowly leaks into the cell down the gradient while K+ slowly leaks out following its gradient.
Extracellular fluid has High Concentration of Na+
Cytosol (intracellular) has High Concentration of K+.
What is Vesicles and what do they do?
A Vesicle is a small round sac formed by budding off from an existing membrane.
1) Vesicles transport substances from one structure to another within the cells.
2) Takes in Substances from extracellular fluid.
3)Releases substances into extracellular fluid.
All movement by Vesicles requires using ATP making it a Active process.