1.2 1.3 Carbohydrates Flashcards
What are carbohydrates?
Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen atoms, typically in a 1:2:1 ratio.
What is the primary function of carbohydrates in living organisms?
Carbohydrates serve as a primary source of energy for cells.
What are monosaccharides?
Monosaccharides are the simplest carbohydrates, consisting of single sugar molecules. Examples include glucose, fructose, and galactose.
How do monosaccharides combine to form disaccharides and polysaccharides?
Monosaccharides can combine through condensation reactions to form disaccharides (two sugar molecules) or polysaccharides (long chains of sugar molecules).
Provide examples of disaccharides.Give me the combination.
sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).
What are polysaccharides, and what roles do they play in living organisms?
Polysaccharides are complex carbohydrates composed of many sugar units. They serve as energy storage molecules (e.g., glycogen in animals, starch in plants) and structural components (e.g., cellulose in plant cell walls).
How are carbohydrates tested for in a laboratory using the Benedict’s test?
The Benedict’s test detects reducing sugars (e.g., glucose) by causing a color change in the presence of these sugars. The color changes from blue to green, yellow, orange, or brick-red, depending on the concentration of reducing sugars.
What are reducing sugars
Reducing sugars can donate electrons.
How do you test for non-reducing sugars in a laboratory?
First, perform the Benedict’s test to check for reducing sugars. If it’s negative (no color change), add hydrochloric acid (HCl) to the sample and boil it to break down non-reducing sugars into reducing sugars. Then, neutralize with sodium hydrogencarbonate (NaHCO3) and perform the Benedict’s test again. A positive color change in the second test confirms the presence of non-reducing sugars.
