Chapter 8: Dynamic Cells Flashcards
What are Phospholids?
Cell membranes primarily made of a double layer.
What is a Hydrophilic (water loving)?
The phosphate head of the molecule.
What is a Hydrophobic (water fearing)?
The lipid tail of the molecule.
What is it called when head dissolves easily in water?
Hydrophilic
What is it called when tail does NOT dissolves easily in water?
Hydrophobic
What is a Phospholipid Bilayer?
2 layers of phospholipid molecules.
The bilayer gives the membrane flexibility and allows it to change shape.
What forms a biological mosaic?
Carbohydrates, lipids, proteins
What is the cell membrane function?
- Biological Barrier (prevents many substances from entering a cell, i.e., viruses, ions, bacteria, salts, etc.)
- Selective Filter (moves only certain substances across the membrane.)
How are your cells semi-permeable?
- Allows certain materials into the cell.
2. Moves wastes out of the cell.
What is Selective Transport?
Movement across membranes.
What is Brownian Motion?
It is when particles in a liquid or air are in constant, random motion.
What is Equilibrium?
A state of balance when all the particles are equally divided.
What is a Net Flow?
Overall division.
What is Passive Transport?
It is the movement across cell membranes without an input of energy.
What are the 2 reasons molecules move?
- Brownian Motion
2. Concentration Gradient
What are 3 Types of Passive Transport?
Diffusion, Osmosis, Facilitated Diffusion
What is Diffusion?
The net movement of particles from an area of high concentration to an area of low concentration.
Why does oxygen diffusing into the cell never reach equilibrium?
Your cells continually consuming oxygen for cellular respiration, therefore, making the concentration of oxygen inside the cell always lower than the concentration of oxygen outside the cell.
What is Osmosis?
The diffusion of water molecules across a membrane where they are more highly concentrated to where they are less concentrated.
What is a Hypotonic Solution?
Lower concentration of solute. Outside the cell (cell = hypertonic)
Water is more concentrated outside the cell and water will enter the cell (cell swells)
What is a Hypertonic Solution?
Higher concentration of solute compared to the inside of the cell (cell = hypotonic)
Water is less concentrated outside the cell and water will leave the cell (cell shrinks)
What is a Isotonic Solution?
Has the same solute concentration on both sides of the cell membrane. This means equilibrium has been reached. Equal amounts of water enters and leaves the cell. No net movement of water.
What happens when a cell is placed into distilled water?
The cell is hypertonic the water moves into the cell, the cell may burst.
What is turgor pressure?
Water pressure within plant cells that allows them to continue to be rigid.