Diffusion Across a Cell Membrane. Diffusion is the movement of a substance across a membrane. Substances diffuse across cell membranes in a process known as passive transport. This means that the cell does not expend any energy in transporting substances across the cell membrane. Instead, substances move down their concentration gradient as a result of random thermal motion.
401k and profit sharing plans are both forms of retirement plans. They allow employees to make pre-tax contributions to an account where contributions and earnings are not taxed until distributed. Some 401k plans require an employer to make contributions to a plan.
A profit sharing plan is a defined contribution plan in which the employer is granted responsibility for determining when and how much the company contributes to the plan. The amount allocated is usually based on the employeeâs salary level or level within the organization. Unlike a 401(k) plan, a profit sharing plan does not allow employees to make contributions. The plan only accepts contributions from the employer. Companies aren't required to contribute a set amount; instead, the amount is based on their discretion.