Biological molecules

Define ‘hydrolysis reaction’

A reaction that breaks down a chemical bond between two molecules and uses a water molecule

Define ‘condensation reaction’

A reaction that forms a chemical bond between two molecules and eliminates a water molecule

Name the three disaccharides + what monosaccharides make them

Glucose + Glucose = Maltose

Glucose + Fructose = Sucrose

Glucose + Galactose = Lactose

(Glue melts, Glue and fruit sucks, Gluey galas lack taste)

What are the small chains found in the cell wall of a plant cell, which are made up of many polysaccharide chains called? And what are the larger threads made up of these called?

Microfibrils + Macrofibrils

Cellulose has many weak ______ bonds between chains

Hydrogen

What make up straight chain Polysaccharides

Beta 1,4 glycosidic bonds

What make up coiled chain polysaccharides

Alpha 1,4 glycosidic bonds

What make up branched and coiled polysaccharide chains

Alpha 1,4 and Alpha 1,6 glycosidic bonds

What makes glycogen/starch a GOOD storage molecule

Compact- coiled structure

Large molecule - cannot cross the cell membrane, therefore stores easily

Insoluble - Does not affect the cells water potential, therefore does not risk interrupting other processes or osmotic lysis (bursting)

What is the name for the coiled parts of a starch molecule

Amylose

What is the name for the branched parts of starch molecule

Amylopectin

How is starch/ glucose best suited for breaking down

Highly branched structure to allow for many sites for enzymes to attach at ends

Explain the test for reducing sugars

1. Grind sample with water and pour into a test tube

2. Add same volume of Benedict’s solution as the volume of the original mixture

3. Heat in a heated water bath for 5 minutes

4. If carbohydrate is present the solution turns from blue to purple

All ______ are reducing sugars

Monosaccharides

What do you test for a carbohydrate if it is not a reducing sugar

1. Perform the Benedict test, if no colour change then

2. Grind sample with water

3. Add acid

4. Boil for 5 minutes (breaking down the carbohydrate down it monosaccharides)

5. To reduce acidity, cool then add alkali

6. Repeat Benedict’s test to look for positive orange colour change

What is the range of colours for the Benedict’s test

Blue - none

Green - very low

Yellow

Orange

Brick red - High due to large amounts of orange precipitate forming

What is the test for starch

1. Add a food sample to a test tube

2. Add two drops of yellow iodine solution, the shake and stir.

3. If a positive test sample should turn blue black

How does iodine work

Takes advantage of starches COILED CHAINS. The iodine (a blue-black substance) binds to the coiled chains in the starch molecule so we can see this new substance

Name the monosaccharide

Alpha glucose

Name the monosaccharide

Galactose

Name the monosaccharide

Fructose

Name the monosaccharide

Beta glucose

What does the “R” group represent

The Rest of the molecule

What is an organic substance

Molecule that contain carbon and at least one other elemnet

Definition of an isomer

Same molecular formula but a different arrangement of atoms

Non-polar molecules are more soluble in ______ solvent

Non polar and viseverser