There are 2 types of transport mechanisms that involve the movement of materials across the cellular membrane:
1. Passive Transport Mechanisms which is the movement of materials that does not require energy. Instead the movement relies on the permeability of the cell. Under this are three kinds of passive transport mechanisms:
a. Simple Diffusion:
- the movement of materials from a region of higher concentration to lower concentration. No external energy is necessary for the movement. The materials supply the energy themselves.
b. Facilitated Diffusion:
- This differs from simple diffusion because the movement is facilitated by proteins that make up the structure of the membrane. The proteins include channel proteins that allow ions and smaller molecules to cross the membrane. The other protein are the carrier proteins, which bind to materials like sugar molecules and move it across the membrane.
c. Osmosis:
- This is the diffusion of water across the membrane. Osmosis moves water from regions where there are more water molecules of water per volume to regions where there are less water molecules per volume.
2. Active transport on the other hand is a movement mechanism that requires energy. It uses the energy to send materials against the direction it is coming from through simple diffusion. This mechanism is used in a way to keep unwanted ions or other materials out of the cell.
Answer:
the answer is the second one
I'm not sure if this is correct, but the answer I got was: endoplasmic reticulum.
I hope this helps, and have a good night! :D
Answer:
D. Alternative splicing is the mechanism that produce complexity in the genes by splicing some of the protein coding part (exons) of a genes
Explanation:
There are certain splicing enhancers sites present in Exons which facilitiates the binding of RNA binding protein specifically SR protein family rich in Serine and Arginine residues. This SR protein will help in splicing of exons.
The significance of this type of mechanism is the ability of a cell to produce an isoform of protein which have retain their function.
This mechanism also help is diversity or in short in evolution.
