Carbs Flashcards
What type of sugar contains a free carbonyl group on an anomeric carbon?
Reducing sugar
What is in equilibrium with an open aldehyde?
Hemiacetal group
What is a non reducing sugar?
A mono and disaccharide that lacks a hemiacetal.
What is another definition for a non-reducing sugar in terms of polysaccharides?
When a polysaccharides ratio of hemiacetals to acetal linkages is very low
What is a special ketone sugar?
Fructose
What disaccharides are reducing sugars?
Maltose and lactose
What disaccharides are non-reducing sugars?
Sucrose
What are three ways that we can test reducing sugar?
Benedict test, Fehling’s test and Tollens’ test
Which which solution has a longer shelflife than Fehling’s solution?
Benedict solution
What is a plant polysaccharide for storage form of energy?
Starch
Which cereal grains are carbohydrates?
Wheat, corn and rice
True or false. Vegetables, roots and tubers are common carbohydrates in the human diet.
True
What legumes are the most common carbohydrates in the human diet?
Soybeans or garbanzo beans
What fruit is a good source of carbohydrates?
Bananas
What makes approximately 1/4 of starch?
Amylose
What is a long linear chain of d- glucose connected by alpha 1, 4 glycosidic linkages?
Amylose
What makes up approximately 3/4 of a starch granule?
Amylopectin
True or false. Amylopectin is highly branched and consist of alpha 1,4 and1,6 linkages
True
How can you test the presence of starch?
Iodine test
What is the principle of the iodine test?
Triiodine interacts with alpha amylose helix and forms a large complex. This complex absorbs light and reflects the blue light only.
Which nutrient is poisonous in high doses?
Iodine
Which component of starch is responsible for gel formation?
Amylose
Which component of starch is responsible for the viscosity?
Amylopectin
What color complex forms when Amylose reacts with iodine?
Blue/ black
