5 Written questions
5 Matching questions
- Types of Transport Across Membranes: Passive Transport
- Cell Membrane Function: A Selective Filter
- Three Types of Passive Transport 3.Facilitated Diffusion
- Three Types of Passive Transport
- a diffusion of molecules across the cell membrane by way of transport proteins.
- b the cell membrane forms a pocket around the material to be transported, then either pinches off as a vesicle or a vacuole.
- c Cell membranes are semi-permeable allowing some materials to cross, while excluding others. They can select a) by particle size
- small enough to enter membrane - O2 H2O
- too large to cross - sugar
b) particular materials to transport across (they bind to chemicals based on their size shape or charge)
- d movement across cell membranes without an input of energy
2 reasons molecules move.
1. Brownian Motion
2. Concentration gradients
- e ...
5 Multiple choice questions
- a state at which molecules are evenly distributed (the concentration is equal throughout the medium)
- molecules continue moving but equilibrium is maintained
- The cell wall of a plant resists the pressure of a water-filled vacuole keeping the plant firm
- the use of vesicles to facilitate movement of substances that are too large to enter or exit the cell via transport proteins
- Peripheral proteins are partially embedded in the inside or outside surface of the membrane
- all matter is made of tiny particles
5 True/False questions
Transport Across Cell Membranes: Concentration Gradient → the movement of only certain substances across the cell membrane
Proteins in membranes serving the following functions → a) moving substances across the membrane
b) carrying out chemical reactions (they act as enzymes)
c) some have "marker" molecules (carbohydrate chains) on their surface allowing cells to recognize each other
d) allow messenger molecules (such as hormones) to attach
e) assist in cell-to-cell communication and control of cell functions
Brownian Motion → in a liquid or gas, particles are in constant, random motion
The Fluid-Mosaic Model → Cell membrane molecules are in constant motion (drifting past each other) resulting in:
a) membrane flexibility
b) cell's ability to change shape
The activities of a living cell depend on the ability of its membrane to → diffusion of molecules across the cell membrane by way of transport proteins.