Carbohydrates Flashcards
(40 cards)
What is a monomer?
A small identical unit from which polymers are made.
What is a polymer?
A molecule made up of three or more identical monomers
What is a condensation reaction?
Reaction which joins two molecules with a chemical bond, eliminating a water molecule.
What bond forms between two monosaccharides?
Glycosidic bond.
What bond forms between two amino acids?
Peptide bond.
What bond forms between glycerol and fatty acids?
Ester bond.
What is a hydrolysis reaction?
Breaks a chemical bond using a water molecule.
What term describes α-glucose and β-glucose?
Isomer(ism).
What monosaccharides form lactose?
Glucose and galactose.
How is lactose formed?
Glucose and galactose joined by condensation to form a glycosidic bond.
Where in the cell is lactose added to a polypeptide to form a glycoprotein?
Golgi apparatus.
Why is glycogen’s structure suited to storage?
- Coiled = compact
- Polymer of glucose = easily hydrolysed
- Branched = faster hydrolysis
- Insoluble = no osmotic effect
Why is glycogen branched?
More ends for faster hydrolysis.
Why is glycogen insoluble?
Prevents loss from cell / avoids affecting water potential.
Why is starch spiral-shaped?
Compact/tightly packed – occupies small space.
How does the helical shape of starch help storage?
Compact / tightly packed / fits lots in a small space.
Why is starch insoluble?
No osmotic effect / does not affect water potential / doesn’t leave the cell.
Why is starch a large molecule?
Long chain = many glucose units = stays in cell.
Why is starch branched?
Rapid hydrolysis to release glucose for respiration.
What is cellulose made of?
Long, straight, unbranched chains of β-glucose.
What bonds hold cellulose together?
Many weak hydrogen bonds.
What structure is formed by cellulose chains?
Microfibrils/macrofibrils.
What do cellulose microfibrils provide?
Rigidity/strength/support to plant cell walls.
Why are hydrogen bonds important in cellulose?
Form cross-links between chains → strength/rigidity (despite individual weakness).
