Fungi are surrounded by a multi-laminate fibrous cell wall which provides rigidity, shape, determines the cellular volume and enables the cell to maintain turgor. The cell wall is composed of polysaccharides and carbohydrates (chitin and cellulose).
Inside the cell wall lies the thin, cytoplasmic cell membrane. The cell membrane is composed of lipid and protein and regulates the passage of substances into and out of the cell, such as metabolites and waste products. Important metabolites are taken up by active transport as the cell membrane is relatively impermeable. The cell membrane is also the first barrier to toxic materials entering the cell and is important in degradation of extra-cellular nutrients.
Reserve materials such as fats, glycogen and protein are stored as granules in the cytoplasm. As the cell ages, vacuoles appear which also contain reserves of metabolites and provide turgor to help keep the cell shape and are important in growth of the organism.