I need help with how markets structure determines prices under pure competition and varying degrees of market power.

I need help composing a summary with a detailed comparison/contrast of the perfectly competitive, price-searcher with low entry, and price searcher with high entry. Be sure to include the following points in your discussion:

• The number and market power of the buyers/sellers, and how these markets have developed as competitive or monopolistic
• How price is determined in each, and the sellers' ability to control price
• The able to price discriminate and the potential benefit of price discrimination
• Level of economic profit that can exist in each, and what happens when the economic profit for a firm in these markets becomes negative
• What forces will limit the ability of a market to be competitive, i.e. what allows monopolies to form and continue to exist