1: Carbohydrates (Quiz)

Organic compounds are...

Carbohydrates are inorganic compounds made up of carbon, hydrogen and oxygen

Monosaccharides have the general formula [blank_start](CH2O)n[blank_end]. Their names are determined by the number of [blank_start]carbon[blank_end] atoms in the molecule. For example, a [blank_start]triose[blank_end] sugar has 3 carbon atoms.

All hexose sugars have the formula C6H12O6

A monosaccharide is

Label the two isomers of a glucose molecule

Tick the boxes that contain the main functions of monosaccharides

Disaccharides are composed of two monosaccharide units bonded together by a glycogenic bond

Is this a condensation or hydrolysis reaction?

Complete the table using the options below

To test for a reducing sugar: 1. Mix equal volumes of [blank_start]Benedict's reagent[blank_end] and sample solution 2. Heat to at least [blank_start]70[blank_end] degrees C 3. If a [blank_start]reducing[blank_end] sugar is present, the solution will turn from [blank_start]blue[blank_end] to a [blank_start]red[blank_end] precipitae

All monosaccharides are reducing sugars

The test for a non-reducing sugar is:

You can test for [blank_start]sucrose[blank_end] by adding sucrase enzymes to the sample. These enzymes [blank_start]hydrolyse[blank_end] sucrose into glucose and [blank_start]glucose[blank_end]. Adding [blank_start]benedicts reagent[blank_end] will show if sucrose is present and the approximate concentration of the solution.

Polysaccharides are formed from 5 monosaccharides

Glucose causes a change in water potential in cells. This is avoided by converting glucose to starch for storage. How does this help the plant? (tick the boxes containing the correct answers)

Starch is made of [blank_start]alpha[blank_end]-glucose molecules bonded together in two different ways, forming [blank_start]amylose[blank_end] and amylopectin. -Amylose is linear and [blank_start]unbranched[blank_end] with 1-[blank_start]4[blank_end] glycosidic bonds. It coils to form a [blank_start]helix[blank_end] -Amylopectin has chains of 1-[blank_start]4[blank_end] glycosidic bonds. It also has branches which are joined to the 1-4 chain by 1-[blank_start]6[blank_end] glycosidic bonds. Amylopectin is a [blank_start]branched[blank_end] molecule

You can test for starch by adding iodine solution. The colour change will be orange/brown to blue/purple

The main storage product in animals is [blank_start]glycogen[blank_end]. It has a1-4 and a1-6 glycosidic bonds making it similar to [blank_start]amylopectin[blank_end], however it has shorter 1-4 chains making it more [blank_start]branched[blank_end].

Cellulose is a structural polysaccharide. It is an important component of [blank_start]cell walls[blank_end] in plants. Cellulose is made up of [blank_start]beta[blank_end]-glucose monomers joined by beta-1-[blank_start]4[blank_end]-glycosidic bonds. The beta link rotates each monosaccharide by [blank_start]180[blank_end] degrees. [blank_start]Hydrogen[blank_end] bonds form between the OH groups on adjacent molecules in parallel chains giving strength. When cellulose molcules become cross linked bundles called microfibrils form. Microfibrilis bundle up to form [blank_start]fibres[blank_end].

Chitin is a polysaccharide found in the exoskeletons of insects and the cell walls of fungi

Label this diagram of a chitin molecule