End of chapter 4 questions Flashcards
which of these molecules contains carbon, hydrogen, oxygen and nitrogen?
A. glycogen
B. lipid
C. cellulose
D. protien
D. protien
which of these would be a positive when boiled with Benedict’s solution?
A. fructose
B. lipid
C. starch
D. protien
A. fructose
which of the following statements about digestion is NOT correct?
A. digestion produces fatty acids and glycerol
B. digestion converts insoluble molecules into soluble molcules
C. digestion changes protiens into amino acids
D. digestion releases energy from food
D. digestion releases energy from food
which of the following organs does NOT produce digestive enzymes?
A. salivary gland
B. gall bladder
C. stomach
D. pancreas
B. gall bladder
describe how you would test water for starch, and for glucose. what would the results be for a ‘positive’ test in each case?
Starch: take a sample of the water in a spotting tile and add a drop of iodine solution. the coluor changes from orange to blue-black.
Glucose: take a sample of the water in a test tube and add blue benedict’s solution. place the tube in a water bath and heat until it boils. a brick-red precipitate results.
what does ‘digested’ mean?
large, insoluble food molecules are broken down into small, soluble ones.
the lining of the stomach secretes hydrochloric acid. explain the function of this.
hydrochloric acid kills bacteria in the food entering the stomach.
when the stomach contents pass into the duodenum, they are still acidic. how are they neutralised?
by alkaline secretions in the bile and pancreatic juice.
describe 4 adaptations of the small intestine (ileum) that allow it to absorb digetsed food efficiently.
- length, which increses time and surface area for absorption
- folds in lining, which increase surface area
- villi covering lining, which increase surface area
- microvilli on lining cells, which increase surface area
- capilary networks in villi, where products are absorbed
- lacteals in villi, which absorb fats
