Lecture 5 - The Carbohydrates: Sugars, Starches and Fibres Flashcards
Why are carbs important?
Good (and main) source of energy, especially for our nerve cells
What are the 3 Carbohydrates family?
Monosaccharides
Disaccharides
Polysaccharides
What are monosaccharides ?
Single sugars
-Glucose, Fructose, Galactose
What are Disaccharides?
Pairs of monosaccharides
-Maltose, Sucrose and lactose
What are Polysaccharides?
Large chains of monosaccharides
-Usually glucose molecules stuck together
What is the body prime source of energy?
Glucose which is a monosaccharide
-also the most abundant sugar we consume
What is the difference between Glucose, Fructose and Galactose?
They are all formed of the same items but all differ in their molecular conformations
What is the sweetest monosaccharide?
Fructose
-what makes honey sweet
Where would you find galactose?
It is not found naturally on its own, it is bound to lactose
-usually called milk sugar
How does galactose split into lactose?
Lactase splits the bond between glucose and galactose so you are ingesting both but separately
Where would you find the disaccharide maltose?
It is not found in nature, but we do consume products that have been malted.
-it is usually a byproduct of starch digestion
What is the disaccharide sucrose normally referred to as?
Table sugar
What 2 monosaccharides make up the 3 disaccharides?
Lactose: Glucose + Galactose
Maltose: Glucose + Glucose
Sucrose: Glucose + Fructose
How are disaccharides formed and broken down?
Formed through condensation reactions
Broken down through hydrolysis reactions
What are the 3 main polysaccharides of carbs?
Glycogen
Stach
Fibre
Which of the 3 polysaccharides are similar?
Glycogen and Starch
- glycogen is the storage form go glucose in animals
- Starch is the storage form of glucose in plants
Where is glycogen stored?
In the liver and in muscle cells as energy reserves
Chemically what does glycogen look like?
They are highly branched chains of glucose
Chemically what does starch look like?
Long, branched (not as branched as glycogen), and unbranched chains
Where do we find most starches in our diet?
Grains, legumes and root crops
What is starch broken down into?
Glucose
Chemically what does fibre look like?
Since it is the structural component of plants, their chains of glucose are arranged in stackable rows in a complex way that our body doesn’t have the machinery to break it down
What are the 2 forms of fibre?
Soluble and Insoluble
What can breakdown fibre in our bodies?
Gut bacteria