Relationship between the (continuous) Fourier transform and the discrete Fourier transform. Left column: A continuous function (top) and its Fourier transform (bottom). Center-left column: Periodic summation of the original function (top). Fourier transform (bottom) is zero except at discrete points. The inverse transform is a sum of sinusoids called Fourier series. Center-right column: Original function is discretized (multiplied by a Dirac comb) (top). Its Fourier transform (bottom) is a periodic summation (DTFT) of the original transform. Right column: The DFT (bottom) computes discrete samples of the continuous DTFT. The inverse DFT (top) is a periodic summation of the original samples. The FFT algorithm computes one cycle of the DFT and its inverse is one cycle of the DFT inverse. Depiction of a Fourier transform (upper left) and its periodic summation (DTFT) in the lower left corner.
Carbohydrates are used by the body for energy and structural support in cell walls of plants and exoskeletons of insects and crustaceans. They are made of smaller subunits called monosaccharides. Monosaccharides have carbon, hydrogen, and oxygen in a 1:2:1 ratio. Monosaccharides or simple sugars include glucose, galactose, and fructose. Although their chemical formulas are the same, they have different structural formulas.
Simple carbohydrates include monosaccharides (one-unit sugars) and disaccharides (two-unit sugars). Monosaccharides include glucose, fructose and galactose. These can be absorbed directly and don't require further breakdown from enzymes, unlike disaccharides and polysaccharides.