Module 2- chapter 3 carbohydrates Flashcards
What is the general formula of carbohydrates?
Cₓ(H₂O)ᵧ
What are carbohydrates in general also known as?
saccharides/ sugars
What are the three types of carbohydrates?
- Monosaccharides
- Disaccharides
- Polysaccharides
What are monosaccharides?
small, simple sugars which will reduce
What are disaccharides?
Large sugars formed from two monosaccharides
what are polysaccharides?
long chain carbohydrates. a type of polymer made up of monosaccharides as monomers
What are some examples of monosaccharides?
glucose, fructose, ribose
what are some examples of disaccharides?
lactose, sucrose, maltose
what are some examples of polysaccharides?
glycogen, cellulose, starch
What is the formula of glucose?
C₆H₁₂O₆
What type of monosaccharide is glucose due to its number of carbons?
hexose monosaccharide (6 carbons)
What is a key property of glucose? Why is this useful?
Highly soluble. Useful because glucose is a major energy source for most cells and is the main form in which carbohydrates are transported around the body of animals.
What makes glucose highly soluble?
- The oxygen in the water molecules as a partial negative charge whilst the hydrogens in the water molecules have a partial positive charge, therefore the overall partial charge of the water is positive.
- The OH groups on the glucose have a partial negative charge so the water and hydroxyl groups bond by dipole bonding.
- The dipole dipole attraction of the water with the glucose hydroxyl groups is stronger than the attraction of the OH group to the carbon chain of glucose.
What are the three ways of drawing the structure of glucose?
Straight chain, ring (most commonly used), simplified ring
What are the two structural variations of the glucose molecule?
Alpha and beta glucose
What can structural variations of molecules be referred to as?
structural isomers
How are alpha and beta glucose different?
Alpha glucose has the hydroxyl group below carbon 1. Beta glucose has the hydroxyl group above carbon 1.
In molecular structure diagrams, how are the carbons numbered?
clockwise from the oxygen atom within the ring
What are condensation reactions?
\when two hydroxyl groups react to bond the two molecules and produce a water molecule. A glycosidic bond forms between the two molecules and oxygen is left behind where the two hydroxyl groups were.
What is a glycosidic bond?
a type of covalent bond formed in condensation reactions between monosaccharides
What do condensation reactions form?
Disaccharides and polysaccharides when two or more monosaccharides are bonded.
How is maltose formed?
by two alpha glucose molecules joined by an alpha 1,4 glycosidic bond.
what type of carbohydrate is maltose?
disaccharide
what type of carbohydrate is fructose?
hexose monosaccharide
what type of carbohydrate is galactose?
hexose monosaccharide
How is sucrose formed?
by glucose and fructose, joined by an alpha 1,4 glycosidic bond
what type of carbohydrate is sucrose?
disaccharide
how is lactose formed?
by galactose and glucose, joined by a beta 1,4 glycosidic bond
what type of carbohydrate is lactose?
disaccharide
is fructose more or less sweet than glucose?
more (sweeter)
is galactose more or less sweet than glucose?
less sweet
is glucose more or less sweet than galactose?
more (sweeter)
is glucose more or less sweet than fructose?
less sweet
Do pentose monosaccharides have alpha and beta isomers?
no
How many carbons do pentose monosaccharides have?
5
which structure is used to draw pentose monosaccharides?
ring
what are two examples of pentose monosaccharides?
ribose and deoxyribose (structural isomers)
What is the difference between ribose and deoyribose?
ribose has one hydrogen atom and one hydroxyl group attached to carbon 2. Deoxyribose has two H atoms and no OH groups on carbon 2.
How can you remember the difference between ribose and dexoyribose?
DEOXYribose is DEOXYgenated compared to ribose (no OH groups so no oxygen on carbon 2)