What is emulsification?
Reveal answer
Breaking large fat drops into small droplets, which increases the surface area for lipase.
Key words: droplets · surface area
2(e) NUTRITION · RECALL
2.31 Roles of bile
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Give the two roles of bile.
Reveal answer
Neutralises stomach acid (alkaline conditions for enzymes) and emulsifies fats.
Key words: neutralise · emulsify
What is meant by the term neutralisation?
Reveal answer
Reaction reducing acidity and moving pH toward neutral.
Key words: neutralisation
What is meant by the term emulsification?
Reveal answer
Physical dispersion of large lipid globules into small droplets.
Key words: emulsification
What is meant by the term surface area?
Reveal answer
Area exposed at an interface where an enzyme can act.
Key words: surface area
What is meant by the term bile salt?
Reveal answer
An amphipathic component of bile that helps disperse lipids.
Key words: bile salt
Two distinct bile functions, Neutralisation. Immediate change? Effect on enzymes?
Reveal answer
Immediate change: Raises pH of acidic chyme. Effect on enzymes: Provides suitable conditions for small-intestine enzymes.
Key words: Neutralisation
Two distinct bile functions, Emulsification. Immediate change? Effect on enzymes?
Reveal answer
Immediate change: Splits large globules into small droplets. Effect on enzymes: Increases surface area for lipase.
Key words: Emulsification
Two distinct bile functions, Lipase action. Immediate change? Effect on enzymes?
Reveal answer
Immediate change: Hydrolyses lipid molecules. Effect on enzymes: Produces fatty acids and glycerol.
Key words: Lipase action
True or false, and why? “Bile chemically digests fat.”
Reveal answer
False. It emulsifies fat; lipase hydrolyses lipid molecules.
True or false, and why? “Emulsification makes less fat.”
Reveal answer
False. The amount is unchanged; total surface area increases.
True or false, and why? “Bile makes the duodenum strongly acidic.”
Reveal answer
False. Its alkaline contribution helps neutralise acidic chyme.
True or false, and why? “Bile has one function only.”
Reveal answer
False. It contributes to both pH control and lipid emulsification.
Why does lipase digest fat faster once bile has been added?
Reveal answer
Bile emulsifies fat → larger surface area for lipase; bile also makes conditions alkaline, closer to the optimum pH for lipase.
Key words: surface area · alkaline
Suggest why acidic chyme must be neutralised before small-intestine enzymes can work well.
Reveal answer
These enzymes have a higher optimum pH → in acid they work slowly or denature.
Key words: optimum pH · denature