Monomers, Polymers and Carbohydrates Flashcards
1
Q
What is amylose?
A
- Formed from alpha glucose monomers
- Chain forms a coiled shape
2
Q
What is amylopectin?
A
- Formed from alpha glucose monomers
- Branched shape
3
Q
Why is amylopectin branched?
A
- It has its branched shape due to the extra alpha 1,6 glycosidic bonding
- More branched means it is more easily hydrolysed into glucose or maltose to provide energy when needed.
4
Q
What is the test for starch?
A
- Add two drops of iodine in potassium iodide to a test solution
- Shake or stir
- If starch is present, the solution will change from yellow/orange to blue-black.
5
Q
What is glycogen?
A
- Formed from chains of monosaccharide alpha glucose
- More alpha 1,6 bonds and less alpha 1,4 bonds which results in extensive branching
- Its main role is energy storage
- It is also stored in small granules, like starch, found mainly in muscle and the liver.
6
Q
What is cellulose?
A
- A major component of plant cell walls
- Formed from chains of the monosaccharide beta glucose
7
Q
What is the structural role of cellulose in plants?
A
- Provide rigidity for plant cells
- Prevents plant cells from bursting when water enters by osmosis
- Maintains turgidity and rigidity in plant cells (and therefore the whole plant) which maximises surface area for photosynthesis
8
Q
What are polysaccharides?
A
- Very large molecules which are insoluble in water
- Formed from many monosaccharide monomers joined together by glycosidic bonds (many condensation reactions)
- When they are hydrolysed they break down into monosaccharides or disaccharides
9
Q
What are the two main functions of polysaccharides?
A
- Energy storage
- Structural role
10
Q
What is starch?
A
- The energy storage polysaccharide found in plants
- Especially large granules found in storage organs and seeds of plants
- Major energy source in our diet
- Made up of the polysaccharides amylose (20%) and amylopectin (80%)
11
Q
What makes starch and glycogen suitable for storage?
A
- Coiled and branched so they are compact for granule storage
- Large insoluble molecules so they are osmotically inactive
- Branched so glucose is easily hydrolysed for use in respiration
- Large molecules so it doesn’t cross the cell membrane and leave the cell.
12
Q
What makes cellulose suited for its structural role?
A
- Long, straight, unbranched chains of beta glucose so long microfibrils and formed
- Hydrogen bonding between these chains so provides rigidity and strength
13
Q
What is a condensation reaction?
A
- Small molecules are assembled into large ones. Chemical bonds are formed and water is produced.
14
Q
What is the purpose of condensation reactions?
A
- Synthesizing complex molecules from simpler ones.
15
Q
What is an example of a condensation reaction?
A
- Protein synthesis
