Which describes the movement of cells?
Cell movement or motility is a highly dynamic phenomenon that is essential to a variety of biological processes such as the development of an organism (morphogenesis), wound healing, cancer metastasis and immune response. In all these examples, cells reach their target by crawling.
What describes simple diffusion?
In biology, simple diffusion is a form of diffusion that does not require the assistance of membrane proteins. In essence, the particle or substance moves from higher to lower concentration. However, its movement does not need a membrane protein that will help substances to move downhill.
What best describes facilitated diffusion?
Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins.
What is the difference between simple diffusion and facilitated diffusion?
In simple diffusion, the molecules can pass only in the direction of concentration gradient. In facilitated diffusion, the molecules can pass both in direction and opposite of the concentration gradient. Simple diffusion permits the passage of only small and nonpolar molecules across the plasma membrane.
What happens when sodium-potassium pump is blocked?
The sodium pump is by itself electrogenic, three Na+ out for every two K+ that it imports. So if you block all sodium pump activity in a cell, you would see an immediate change in the membrane potential because you remove a hyperpolarizing current, in other words, the membrane potential becomes less negative.
Which type of transport is active?
In cellular biology, active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement.
What are the two main types of transport proteins?
Carrier proteins and channel proteins are the two major classes of membrane transport proteins.
What is the most efficient mode of transportation?
The most energy-saving form of public transport is the tram or underground train, at just 0.05 and 0.08 kWh per kilometre travelled. Using the ADEME calculator, energy and CO2 consumption can also be calculated for the selected form of mobility.