Lecture 2 Flashcards
What is the difference between an oligosaccharide and a polysaccharide?
Oligosaccharides are typically made up of 4 - 20 monosaccharides and polysaccharides have more than 20.
What is the difference between glucose and dextrose?
There is no difference. Glucose and Dextrose are different names for the same molecule.
Which of the monosaccharides is sweetest?
fructose is the sweetest of the monosaccharides. It occurs naturally in honey and fruit.
Where would you typically find galactose?
As part of another disaccharide or polysaccharide.
Which foods have lots of starch and which have lots of simple sugars?
Potatoes and other vegetables have lots of starch. Fruit have lots of simple sugars.
Does meat contain any carbohydrates?
Meat contain some glucose and glycogen but in very small amounts.
Which sugars are typically found in sugarbeet?
Sugarbeet contains mostly sucrose.
Which sugars are typically found in sugar cane?
Sugar cane contains glucose, fructose, and sucrose.
How are D and L sugars different to each other?
D-sugars are the mirror image of L-sugars.
What differentiates different sugars of the same family?
Difference between different sugars of the same family is the amount of carbon atoms and the position of the hydroxyl groups.
What form does fructose take in solution?
The furanose form.
What form would you expect glucose and other monosaccharides to typically be in solution?
The pyranose form
What is the alpha position of a haworth projection?
alpha position is the first carbon of the haworth projection
Which form of a monosaccharide is favoured in an equilibrium reaction between its open chain form and its ring form?
Ring form
How is the ring sugar structure formed?
carbon 5 and aldehyde group react together to form the ring structure.
What is maltose made up of? What linkage links the subunits?
Maltose is a disaccharide fragment derived from starch composed of 2 D-glucose connected via an alpha -(1,4)-glycosidic bond.
What enzyme breaks down maltose? What are the resultant monosaccharides?
Maltase, yielding 2 glucose molecules.
What is the resultant sugar of alpha amylase digestion in the intestine?
maltose
Where is alpha amylase produced?
alpha amylase is made by the pancreas
What is lactose made up of? What linkage links the subunits?
Lactose is made up of 1 D-galactose and 1 D-glucose molecule joined by a beta-(1,4)-glycosidic bond.
What is sucrose made up of? What linkage links the subunits?
Sucrose is made of 1 unit alpha-D-glucose and 1 unit of beta-D-fructose joined by an alpha-(1,2)-glycosidic bond.
Is fructose a reducing or non-reducing sugar?
fructose is a non-reducing sugar. Can be determined using the silver mirror test.
Which is sweeter glucose or fructose?
Fructose is sweeter than sucrose (1.4x)
What is the use of glycogen?
Glycogen is the storage form of glucose in the body and provides a rapid energy release when required.
