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 type of plan that gives employers flexibility in designing key features. It allows the employer to choose how much to contribute to the plan (out of profits or otherwise) each year, including making no contribution for a year. Employers start a profit sharing plan for additional reasons: A well-designed profit sharing plan can help attract and keep talented employees.