Ch. 5: The Dynamic Cell


Terms in this set (...)

What makes up the cell membrane?
Phospholipid Bilayer
What is the phospholipid bilayer structure?
Glycerol, 2 Fatty Acids (hydrophobic), a PO4 group (hydrophilic).
Intracellular Fluid
Watery fluid inside the cell.
Extracellular Fluid
Watery fluid outside the cell.
What are the parts of the cell membrane?
Phospholipids, Cholesterol, Proteins, Glycoproteins and Glycoproteins
What is the function of phospholipids in the membrane?
It provides the basic structure of the membrane.
What is the function of cholesterol in the membrane?
It stabilizes phospholipids and provides fluidity. It is found in animal cells. Not normally present in bacterial or plant cells.
What is the function of proteins in the membrane?
It can perform functions such as transport, catalyzing chemical reactions, acting as receptors, and anchoring the membrane to the rest of the cell.
What are the functions of glycoproteins and glycolipids in the membrane?
Some proteins and lipids have sugars attached. They tell the cell that it is you and not a bacteria.
What does selectively permeable mean?
The cell membrane will only allow certain things in and out of the cell.
What is the selectively based on?
What is passive transport?
It moves things across the membrane in the direction of high to low.
What are the properties of passive transport?
No energy required, small particles.
When does passive transport stop?
When equilibrium is reached.
What is the goal of passive transport?
To have equal concentrations of solutes inside and outside the cell.
What are the three types of passive transport?
Diffusion, Facilitated Diffusion, and Osmosis.
Small solutes move from side of high concentration to low.
What is tonicity?
It describes the amount of solute in a solution compared to the amount of solute in a cell.
Facilitated Diffusion
It is like diffusion except the substance moving is going through a carrier protein in the membrane.
A special form of diffusion where the only thing moving is water. It moves from the side of the membrane that has high water to the side that has low water.
Examples of osmosis in action
Cells shrink in a hypotonic solution.
Cells swell in a hypertonic solution.
Hypertonic Solution
The solution has more solute relative to what it is being compared to. It has less water relative to what it is being compared to.
What happens to the cell placed in a hypertonic solution?
The cell swells.
Hypotonic Solution
The solution has less solute relative to what it is being compared to. This means it has more water relative to what it is being compared to.
What happens to the cell placed in a hypotonic solution?
The cell shrinks.
Isotonic Solution
The concentration of solute on each side of the membrane is equal.
What happens to the cell in an isotonic solution?
Nothing happens to the cell.
What is active transport?
It means that energy is required for the process to occur.
Examples of active transport
Eating: Cells use ATP to pump large numbers of Hydrogen atoms into the stomach.
How do solutes move in active transport?
Solutes move against their concentration gradients.
What is bulk transport?
It is used when items are too big to cross the cell membrane by other means.
What is the difference between endocytosis and exocytosis?
Endocytosis: Movement of large molecules into the cell.
Exocytosis: Movement of large molecules out of the cell.