Biology Topic 1- Monomers and carbohydrates

A01 questions definition for reviewing content

What is a monomer?

Small single molecular basic units that act as building blocks to create larger molecules

Give me examples of monomers

nucleotide

What is a polymer

large complex molecules mad of many monomer chains

Give examples of polymers

Polysaccharides

What are Condensation reactions?

The joining of two molecules together that forms a chemical bond by removing a water molecule

What is a hydrolysis reaction?

A reaction where a chemical bond is broken between two molecules by adding a water molecule

What are carbohydrates made of?

Monosacchardies

What are monosaccharides?

Monomers which make large carbohydrates

Give examples of monosaccharides

Glucose

What bond does a condensation reaction between two monosaccharides form?

A glycosidic bond

What else forms between a condensation reaction between two monosaccharides?

A disaccharide 

What does the condensation reaction of 2 glucose molecules make?

maltose

What does the condensation reaction of glucose and fructose make?

Sucrose

What does the condensation of glucose and galactose make?

Lactose

Glucose has two isomers. What does isomer mean

Molecules or compounds that have the same molecular formula but they are structured differently from their atoms

What are the two isomers of glucose?

Alpha and beta glucose

How are the two isomers of glucose different different?

Alpha glucose and beta glucose have their groups reversed

What are polysaccharides?

Polymers made up of many monosaccharides from a condensation reaction

Name 3 polysaccharides

Starch, Glycogen and cellulose

Describe the structure of starch

1- Polymer of many alpha glucose molecules joined together by condensation reactions

2- 1-4 and 1-6 glycosidic bonds

3- Starch Made of two polymers Amylose and amylopectin

4- Amylose is where in starch the glucose monomers are joined by 1-4 glycosidic bonds which gives starch its spiracle/coiled shape

5- Amylopectin - glucose monomers joined in both 1-4 and 1-6 glyscosidic bonds resulting in branches

Why is starch a good storage Molecule?

Insoluble - Because its a Large molecule, so it won’t dissolve and therefore won’t affect the water potential of a cell.

Describe the structure of Glycogen

1- Stored in liver and muscle cells

2- Polymer of alpha Glucose

3- 1-4 and 1-6 Glycosidic bonds between glucose monomers when joined together by condensation reactions

4- Highly branched as has lots of 1-6 glycosidic bonds

Explain how Glycogen is a good storage molecule

Insoluble because its a large molecules, so won’t dissolve when stored in cells and therefore won’t affect water potential of cells.

Describe the structure of Cellulose

1- Polysaccharide of beta glucose

2- 1-4 glycosidic bonds between monomers

3- Unbranched 

4- long parallel straight chains of beta glucose held together by hydrogen bonds = fibril

5- fibrils align parallel  and held by hydrogen bonds to create microfibrils.

Explain How cellulose is a good storage molecule

Insoluble because its a large molecules, so won’t dissolve when stored in cells and therefore won’t affect water potential of cells.

Describe how you can test for a reducing sugar

Use Benedict’s test for reducing sugar,

1-Add benedict’s reagent to a test tube containing sample

2-Heat soloution in water bath

3- Positive = Coloured precipitate of brick red formed

4-Filter solution and weigh the precipitate for comparing reducing sugars.

How can you test for non-reducing sugars such as sucrose?

1-Add  dilute hydrochloric acid to new sample in test tube

2-Heat it in a water bath

3- Neutralise solution with sodium hydrogen carbonate 

4- Carry out Benedict test for reducing sugars

5- Positive = coloured precipitate of brick red formed