EMPA revision Cards

Q: Which one, or more, monomer units make up each of the following?

• Lactose
• Sucrose
• Starch

A:

• L = Glucose + Galactose
• Su = Glucose + Fructose
• St = Glucose only.

Q: In lactose intolerant people, micro-organisms in the large intestine convert the undigested lactose into gas, which accumualtes and causes discomfort. by which process do micro-organisms probably produce this gas?

A: Respiration

Q: suggest a reason why the gas is unlikely to be carbon dioxide?

A: Carbon dioxide forms as the result of aerobic respiration.

Conditions in the large intestine are anaerobic.

Q: Explain why enzymes function less well at lower temperatures.

A: To function enzymes must physically collide with their substrate. lower temperature decrease the kinetic energy of both enzyme and substrate molecules, which then move around less quickly.They hence collide less often therefore react less frequently.

Q: Explain how high temperatures may completely prevent enzymes from functioning.

A: Heat causes hydrogen and other bonds to break. the tertiary structure of the enzyme molecule changes, as does the active site. the substrate no longer fits the active site.