Exam-style questions Flashcards
Use a labelled diagram to show how triglyceride is formed
- show elimination of water
- show glycerol and 3 fatty acids
- show ester bond
Explain 2 ways in which the structures of amylose and glycogen make them suitable for energy storage
- compact, so store a large volume of energy in a small space
- insoluble in water, so don’t affect osmosis
Explain how the dipolar nature of water is essential for living organisms
- water is adhesive and cohesive, so acts as a solvent by transporting substances around the body
- distribute heat round the body
meaning hydrolysis
the breaking of bonds, with the addition of water
name an organelle found in cells f both eukaryotic and prokaryotic organisms
ribosomes
Describe the roles of the Rough Endoplasmic Reticulum (RER), the Golgi apparatus, and vesicles in the synthesis and secretion of digestive enzymes
the RER has 70S ribosomes, and produces polypeptides by joining amino acids by peptide bonds. The proteins are then transported to the Golgi apparatus via vesicles. The proteins are modified in the Golgi apparatus, and are then released by exocytosis via secretory vesicles
Using your knowledge of starch and cellulose, suggest why it is necessary for fungi to produce different enzymes to digest these 2 substances
- starch contains alpha-glucose monomers, whilst cellulose contains beta-glucose monomers
- starch contains 1,6-glycosidic bonds, whilst cellulose doesn’t
- starch contains amylopectin and amylose
- cellulose has a straight-chain structure, whilst starch has a branched structure
Explain why it may be better to make packaging from starch rather than from oil-based products
- starch is cheaper
- using starch is more sustainable, as the plants can be regrown
give 2 differences between the RER and chloroplast
- in the RER, the ribosomes are attached, not floating
- the RER doesn’t contain DNA
Compare the structure of a cellulose molecule with the structure of starch
- cellulose is made up of beta-glucose monomers whilst starch is made up of alpha-glucose monomers
- starch has 1,6-glycosidic bonds, whilst cellulose doesn’t
- both cellulose and starch have 1,4-glycosidic bonds
- both made up of glucose
Explain how the arrangement of cellulose microfibrils contributes to the physical properties of plant fibres
cellulose provides strength because of the criss-cross arrangement of microfibrils
