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.
For income tax purposes, partnerships are not taxable entities. Rather, they are treated as conduits, in which the items of partnership income, deduction and credit are allocated among the partners for inclusion in their respective income tax returns. Before 1982, the IRS audited partnerships at the partner level, with any adjustments made to each partners return.