Carbohydrates Flashcards
What are Carbohydrates?
Organic molecules with the chemical formula Cx(H2O)y.
True or False: Generally, carbohydrates are the most abundant compound in foods.
True. Some examples include cereals (excluding beer), starchy roots, sugar and sweeteners, milk (excluding butter).
What is a Monosaccharide?
A single unit that is not covalently bonded to another unit.
What are examples of Monosaccharides?
Glucose, fructose, galactose.
What are Disaccharides?
Two monosaccharide units covalently bonded together.
What are examples of Disaccharides?
Sucrose, lactose, maltose.
What is Sucrose made of?
Glucose + fructose.
What is Lactose made of?
Glucose + galactose.
What is Maltose made of?
Glucose + glucose.
What are Oligosaccharides?
2-10 monosaccharide units covalently bonded together.
What is Raffinose?
Composted of glucose, fructose, and galactose, and available in beans, cabbage, broccoli, etc. It is undigested in the human stomach and upper intestine, and digested in lower intestine by gas producing bacteria.
What can help Raffinose be digested?
Soaking beans in water reduces raffinose-type oligosaccharides.
What are Polysaccharides?
More than 10 monosaccharide units covalently bonded together.
What are examples of Polysaccharides?
Starch (carbohydrate storage in plants), cellulose (carbohydrates of plant cell wall) and glycogen (animal starch).
What is the chemical formula of Glucose?
C6H12O12.
What is the difference between a-d-glucopyranose and b-d-glucopyraose?
Alpha has the hydride chain on the bottom, and beta has the hydride chain on the top.
What are the main differences between glucose and galactose?
The sweetness and how the monosaccharide reacts with other molecules.
What is the difference in structure between glucose/galactose and fructose?
Glucose/galactose is a 6-structure ring while fructose is a 5-structure ring (because of the ketone group).
Which is sweeter: glucose or fructose?
Fructose.
What enzyme converts glucose to fructose?
Glucose Isomerase.
What enzymes breaks down sucrose and what are the end products?
Sucrase enzyme breaks down sucrose into glucose and fructose.
Which is sweeter: sucrose or fructose?
Fructose.
What is the major sugar component of dairy milk?
Lactose.
What enzyme breaks down lactose?
Lactase enzyme breaks down lactose through hydrolysis in the gastrointestinal tract.
What is Lactose Intolerance?
The lack of lactase.
What is Lactaid milk?
Milk with added lactase enzyme. Sweeter than regular milk because of the glucose and galactose.
What is BioBest yoghurt?
Yogurt that is 90% lactose free, and sweeter than regular yoghurt.
Where does sugar come from?
Cane sugar (10% sugar) and beet sugar (17% sugar).
What is the order of the industrial production of sugar crystals?
1) Sugar beets
2) Juice extraction
3) Juice purification
4) Evaporation
5) Crystallization
6) Recrystallization
7) Refine sugar crystals
Order the following from most sweet to least sweet, using the Relative Sweetness Scale:
Lactose, galactose, sucrose, fructose, glucose.
Fructose (140-150), Sucrose (100), glucose (70-80), Galactose (35), Lactose (20).
What is High Fructose Corn Syrup?
Corn syrups
