12.1 Carbohydrates and lipids Flashcards
Monomers definition
Small, identical molecules that can join together by condensation reaction to form polymers
Polymers definition
3 or more similar or identical monomers that join together by condensation reaction
Condensation reaction definition
Joins two monomer molecules together
Removes water to form a bond
Hydrolysis reaction definition
Breaks a bond between two monomers
Forms one water molecule
Monosaccharides bond and example
Glycosidic bond
Starch, glycogen and cellulose
Amino acids bond and example
Peptide bond
Haemoglobin
Nucleotides bond and example
Phosphodiester bond
RNA or DNA nucleotides
What monosaccharides is maltose made from?
Two alpha glucose monosaccharides
What enzyme hydrolyses maltose?
Maltase
What monosaccharides is lactose made from?
Alpha glucose and galactose
What enzyme hydrolyses lactose?
Lactase
What monosaccharides is sucrose made from?
Alpha glucose and fructose
What enzyme hydrolyses maltose?
Maltase
Describe the similarities and differences between the structures of amylose and amylopectin
Similarities:
- Both have 1-4 glycosidic bonds
- Both are insoluble so don’t affect the water potential of the cell
- Both alpha glucose
- Both large so can’t diffuse out of the cell
Differences:
- Amylopectin has 1-4 and 1-6 glycosidic bonds whereas amylose just has 1-4
- Amylose is straight whereas amylopectin is branched
- Amylose is compact so good for storage whereas amylopectin has a large surface area for rapid hydrolysis of glucose for respiration
Describe the structure of amylose
Amylose is a straight, unbranched chain of alpha glucose
It has 1-4 glycosidic bonds which coil into an alpha helix
It is insoluble so doesn’t affect the water potential of the cell
It is compact so good for storage
It is large so doesn’t diffuse out of the cell
Describe the structure of amylopectin
Amylopectin is branched chains of alpha glucose
It has 1-4 and 1-6 glycosidic bonds
It has a large surface area for rapid hydrolysis of glucose for respiration
It is large so doesn’t diffuse out of the cell
It is insoluble so doesn’t affect the water potential
Where is glycogen found?
Only in animal cells
It is usually stored in the liver and muscles
How is glycogen different to starch?
Glycogen has shorter chains, more branches and a larger surface area
Describe the structure of cellulose
Cellulose is ling unbranched chains of beta glucose
It has 1-4 glycosidic bonds
Each beta glucose is inverted 180 to its neighbouring unit
It has many weak hydrogen bonds between the layers that form microfibrils to provide strength and rigidity
What are the 3 tests for carbohydrates?
Iodine
Reducing sugars
Non reducing sugars
What is the Benedict’s test for reducing sugars?
Add Benedict’s solution to a sample
Heat to 95C
Brick red precipitate forms if reducing sugar is present
What is the Benedict’s test for non reducing sugars?
If there is no change to the Benedict’s test
- Heat with acid
- Neutralise with alkali
- Add Benedict’s reagent
- Heat to 95C
- Brick red precipitate forms if non reducing sugar present
What is the test for starch?
Add potassium iodine to sample
Blue/black indicates starch present
What are the two types of lipids?
Triglycerides and phospholipids
Describe the structure of triglycerides
Contains 3 fatty acids and a glycerol
Ester bonds formed between the carboxyl group of the fatty acid and the hydroxyl group of the glycerol
Describe the structure of phospholipids
Contains 2 fatty acids, a glycerol and a phosphate group
Hydrophilic, non-polar phosphate group and hydrophobic fatty acid tails
forms bilayers and micelles in water
Unsaturated definition
Contains C=C within the hydrocarbon chain
Saturated definition
No C=C within the hydrocarbon chain
