Basically, all carbohydrates are monosaccharides. But, nonetheless they are not all alike!
Carbohydrates are made up of individual sugar components, and are differentiated according to type and number of constituents as follows:

What happens when the carbohydrates hit the blood?

Carbohydrates are broken down to monosaccharides in the intestines, and then enter the blood stream. The glucose level in the blood increases and this triggers a release of insulin. Insulin “removes” the glucose from the blood. The glucose is transported into the muscles and into the fatty tissue.
A lot of glucose -> a lot of insulin -> fast deficiency of sugar
Fructose, however, does not cause a release of insulin, and thus is absorbed by the blood stream slower than glucose. In a mixture with glucose, fructose reduces the insulin reaction, so to speak, and thus prevents a fast drop in glucose level.

How fast do the carbohydrates get into the blood?

The length of the carbohydrate chain is not responsible for the speed, in which the carbohydrates (because they are broken down fast) pass through the intestines into the blood, but the accompanying matter in the food, such as the dietary fibres, fat, and protein. They determine the dwell time of the food in the stomach, and thus the absorption by the blood.

Dietary fibres
The fibres delay the emptying of the stomach, and slow down the flow of carbohydrates into the blood. For this reason, the glucose level and the insulin level do not increase as much. Resulting in the supply energy for a longer period of time.

Roughly speaking, dietary fibres are differentiated according to soluble and nonsoluble dietary fibres. Soluble dietary fibres, such as oatmeal, have a favourable water-binding ability, and are easier to digest. They swell up and form a gelatinous liquid, which surrounds the food constituents. Dietary fibres enhance our digestion, contribute to a healthy intestinal flora, and have an overall positive effect on our health. For this reason, we should digest about 30 g of dietary fibre every day. This is the reason why PowerBar Performance and Harvest have been developed on the basis of oats.

Which carbohydrates should be preferred?

Many polysaccharides (complex carbohydrates) rich in starch, such as cereals, bread, noodles, rice (whole grain), potatoes, PowerBar Performance and Harvest.
Few monosaccharides, little sugar, such as in sweets, but rather a lot of fruit (fructose!)