Biology, Carbs And Lipids Flashcards
What is a monomer?
Monomer’s are small identical or similar molecules which can be condensed to make larger molecules.
What is a polymer
Polymers are large molecules made from condensing 3 or more identical or similar monomers together.
State and describe the type of reaction involved in breaking a chemical bond.
Hydrolysis- the addition of water to break a named chemical bond.
State and describe the type of reaction involved in forming a chemical bond.
Condensation- the removal of water to form a named chemical bond.
Name the bond between carbohydrate monomers.
Glycosidic bond
How is sucrose, lactose and maltose formed?
Sucrose- glucose and fructose
Lactose- glucose and galactose
Maltose- glucose and glucose
How do you remember monosaccharides?
A-glucose- Penguin
B-glucose- Egyptian hands
Fructose- House
Galactose- Raver
Describe the biochemical test for reducing sugars.
1- Add Benedict’s solution and heat to 95C
2-Red precipitate shows presence of reducing sugar
Describe alternate ways to measure the concentration of a reducing sugar.
1- Calibration curve
2- Filter and dry. Then find the mass
Explain how the structure of a cellulose relates to its function.
1- long, straight, unbranched chains of beta glucose
2- joined by many weak hydrogen bonds
3- to form microfibrils
4- because many weak hydrogen bonds are strong in large numbers
5- providing strength and rigidity to the cells walls
Explain three ways in which starch molecules are adapted for their function in plant cells.
Insoluble SO doesn’t affect water potential
Helical/ coiled SO compact
Large SO doesn’t leave the cell
Describe the biochemical test for a non-reducing sugar, (sucrose).
1- Benedict’s test gives negative result
2- add HCl and heat to 95C
3- add an alkali to neutralise
4- add Benedict’s solution and heat to 95C
5- red precipitate shoes presence of non-reducing sugar
Describe the potassium iodide test for starch.
Add potassium iodide solution
Black shows presence of starch
Describe how a triglyceride is formed.
ONE glycerol, THREE fatty acids
THREE condensation reactions
THREE ester bonds
What is a saturated fatty acid?
Maximum number of hydrogens
What is an unsaturated fatty acid?
Double bond between carbon atoms
Describe the emulsion test.
1- Grind sample to release lipids
2- mix with ethanol and shake
3- add water and shake
4- positive result is a cloudy, white emulsion
What does an emulsion test detect?
Lipids
Describe the buriet test.
1- add buriet reagent to sample
2- positive result is purple
What does the buriet test detect?
Proteins
Compare and contrast the structure and properties of triglycerides and phospholipids.
BOTH contain water bonds,
BOTH contain glycerol,
BOTH insoluble in water,
BOTH contain C,H and O WHEREAS phospholipids also contain P,
Triglycerides have 3 fatty acids WHEREAS phospholipids have 2 fatty acids,
Triglycerides are hydrophobic WHEREAS phospholipids are hydrophilic,
Phospholipids form monolayer/bilayer/ micelle WHEREAS triglycerides do not
Describe how the structure of glycogen is related to its function
Helix SO compact
Polymer of glucose SO easily hydrolysed
Branched SO more ends for hydrolysis
Insoluble SO doesn’t affect water potential
Glucose SO provides respiratory substrate for energy
