Structural and Storage Molecules Flashcards
Difference between Alpha and Beta Glucose
- Alpha glucose has the Hydroxyl group on the 1st carbon facing inside the ring, whereas Beta faces outwards
- Alpha glucose has H atom on 1st carbon facing outside the ring, whereas on beta it faces inwards
Describe the formation of glycosidic bonds in amylase
- Alpha glucose molecules
- Undergo condensation polymerisation
- Between hydroxyl groups on carbon 1 and 4, forming a 1,4 - Glycosidic bond
- Where a water molecule is released
What is starch made from?
Alpha glucose molecules
- Amylose (just 1,4 - glycosidic bonds)
- Amylopectin (forms 1,4 - glycosidic bonds and some 1,6 - glycosidic bonds forming the branches)
What is Cellulose made from?
Beta glucose molecules
What is Glycogen made from?
Alpha glucose molecules
- Forms 1,4 glycosidic bonds but also 1,6 glycosidic bonds
- These 1,6 glycosidic bonds cause the branching, and therefore its structure is similar to amylopectin but it has MORE branches
Properties of STARCH
- Insoluble (so wont affect water potential in cells)
- Spiral shape (compact, lots of glucose molecules stored in small space)
- Metabolically inactive, so doesn’t affect any effect on the chemical reactions in a cell
Properties of Glycogen
Similar in structure to Amylopectin, but forms 1-6 glycosidic bonds, making it a BRANCHED structure
- Insoluble (so will not affect water potential in cells)
- Compact Branched Structure (1) (many glucose molecule stored in a small place
- Compact Branched Structure (2) (More ends to be hydrolysed by enzymes)
Properties of Cellulose
Straight Chain polymer due to positioning of OH group involved in glycosidic bond
Parallel chains lying side by side held together by hydrogen bonds. Form microfibrils which join together in larger bundles to form cellulose fibres. These microfibrils can be surrounded by different polysaccharides.
- Extra Strength (comes from hydrogen bonds between chains)
- Cellulose is difficult to digest because animals dont have enzymes to break 1,4 -Glycosidic bonds
Uses of Carbohydrates
- Immediate source of energy (glucose)
- Transport carbohydrates (Sucrose in plants)
- Structural carbohydrates (cellulose)
- Storage carbohydrates (glycogen in animals, starch in plants)
Uses of Carbohydrates
- Immediate source of energy (glucose)
- Transport carbohydrates (Sucrose in plants)
- Structural carbohydrates (cellulose)
- Storage carbohydrates (glycogen in animals, starch in plants)
- Conjuncted Carbohydrates
- Glycolipids
- External structures of cell membranes
- Glycoproteins
- External structures of cell membranes (antigens)
- Mucus of respiratory and digestive tracts
- Glycolipids
Amylose Properties
- Helix shape (coiled)
- 1,4 glycosidic bonds
- Not Branched
- Monomer is alpha glucose
- Source is plants
What are hydrogen bonds?
- Form between water molecules
- Form due to water’s polarity (positively and negative charged regions of water molecule)
- Weak bonds, but in large numbers they can form a strong structure
What is a Triglyceride?
- One Glycerol Molecule
- Bonded to 3 fatty acid chains
How do Triglycerides form?
- Condensation reaction between -COOH group of fatty acid
- With each of the -OH groups on the glycerol molecule
- Ester bonds form between each 3 of the bonds between the -OH and -COOH groups
-H2O is released as a product too - Reaction is reversible if triglyceride is hydrolysed
What does saturated mean?
No double bonds