Plant cells have everything an animal cell has, plus more. A rigid cell wall outside the membrane protects the cell, supports it and gives it shape. Chloroplasts hold chlorophyll, a green pigment that captures light energy so the plant can make its own food. A large central vacuole stores water and keeps the cell firm. Water travels through plant tissue in xylem, which a celery stalk in tinted water makes visible. Leaves look green because chlorophyll absorbs red and blue light and reflects green.