Answer:
1. fatty acids : Facilitated Diffusion
2. Cl- : Simple Diffusion
3. CO2: Simple Diffusion
4. steroid hormones : Facilitated Diffusion
5. amino acids: Simple Diffusion
Explanation:
Simple Diffusion: This is a pathway for some small polar hydrophilic molecules that can freely move through momentary openings in the membrane that are formed as a result of lipids movements. Membrane´s permeability depends on the size of the molecule, the bigger the molecule is, the less capacity to cross the membrane it has. Diffusion is a very slow process and to be efficient requires short distances and pronounced concentration gradients. Examples of molecules that are transported by simple diffusion are H₂O, O₂, CO₂, NH₃, Ca⁺, Cl⁻, Na⁺, steroid hormones, among others.
Facilitated Diffusion: Refers to the transport of hydrophilic molecules that are not able to freely cross the membrane. Channel protein and many carrier proteins are in charge of this passive transport. If uncharged molecules need to be carried this process depends on concentration gradients and molecules are transported from a higher concentration side to a lower concentration side. If ions need to be transported this process depends on an electrochemical gradient. The glucose, monosaccharides, amino acids, fatty acids, among others, are examples of molecules transported by facilitated diffusion.
Simple diffusion and facilitated diffusion are passive transport processes because the cell does not need any energy to make it happen.
Answer:
a. Simple difussion – 2, 3, 5
b. Facilitated difussion – 1, 4
Explanation:
Simple diffusion is an unassisted type of diffusion hence the name simple, in which a particle moves from higher to a lower concentration.
It occurs through the phospholipid bilayer Transports small, non-polar particles. It happens directly through the cell membrane.
The rate of simple diffusion is directly proportional to the concentration gradient and the membrane permeability of the solute molecule.
Examples of simple diffusion of gases is seen to happen across the respiratory membrane, diffusion of molecules from the blood to the cells through the interstitial fluid and occurs in nature a lot.
Facilitated diffusion is the transport of substances across a biological membrane through a concentration gradient by means of a carrier molecule.
It happens with the aid of transmembrane proteins.
Serves to transport large or polar particles. This occurs through specific facilitator molecules.
The rate of facilitated diffusion depends on the kinetics of carrier- mediated transport
Examples of where facilitated diffusion occurs are thus; in the counter-transport of chloride/bicarbonate in renal tubular cells, cotransport of sodium with sugars like glucose, galactose,etc
