B3-Digestion Flashcards
How does temperature effects enzyme controlled reactions ?
Increasing temperature increases rate of reaction up to certain point. This point is called the ‘optimum’ temperature and if it goes higher than this temperature the enzyme will ‘denature’ (bonds are broken) changing the ‘active site’ shape meaning that the reaction stops.
How does pH effects enzyme controlled reactions ?
All enzymes have an optimum pH at which they work best. In conditions with a lower or higher pH, the pH starts to interfere with bonds that hold the enzyme in the correct shape causing the ‘active site’ to change shape and therefore stop the reaction.
What is the name of the group of enzymes that breakdown carbohydrates into simple sugars?
Amylases
What is the name of the group of enzymes that breakdown proteins into amino acids ?
Proteases
What is the name of the group of enzymes that breakdown lipids (fats) into glycerol and fatty acids?
Lipase
Where in the digestive system is water reabsorbed?
Large intestine
Where is bile produced?
The liver
Which acid is produced by the stomach?
Hydrochloric acid
What are the finger-like projections in the small intestine called?
Villi
How is food moved through the gut?
By peristalsis
By gravity
By waves of liquid
By peristalsis
The enzyme that starts the chemical digestive process at the mouth is..
Amylases (for the starch)
Before it is Egested, faeces is retained in the …
Rectum
Absorption of carbohydrates, proteins and lipids occurs in the…
Small intestine
Which solution can be used to test for starch?
Iodine solution
Where in the digestive system are lipase enzymes produced
Pancreas and small intestine
Why is bile needed?
- to emulsify fats
- to raise the pH of the stomach so the enzymes aren’t denatured
Protease break down……. into ……
Protein into amino acids
Lipase break down …… into …..
Lipids into glycerol and fatty acids
What is the name of the area where the enzyme binds to the substrate?
The active site
What do you call it when the substrate has reached the active site of the enzyme?
Enzyme-substrate complex
The “lock and key” model shows how the …..
Substrate binds onto the active site
What is the function of hydrochloric acid in the stomach?
To provide the optimum pH for the working enzymes in the stomach
Why is it necessary to breakdown large insoluble food molecules into smaller soluble molecules?
- as they cant be absorbed into the bloodstream
- small, soluble molecules can be absorbed into the blood stream to construct new carbohydrates, proteins and lipids in the body
- some glucose produced by digestion is used for respiration
Why are enzymes important in the metabolism of cells or organisms?
Chemical reactions needed for life could not take place fast enough without enzymes to speed them up
Explain why emulsification is important?
Fats do not mix with other liquids in digestive system, staying as large molecules that are hard for lipase enzymes to act on.
Larger surface area produced by bile action
allows enzymes to reach more fat molecules and break them down more quickly.
