2.
The building blocks of the starch molecule are made of glucose.
3. I think the reason that all the results turned positive after the extra two minutes in Josh and Thomas's lab is because the carbohydrate molecules finally got the additional time that they needed to break apart, releasing the simple sugars (glucose).
4. The life of a pear: The food begins its journey starting with the mouth where mechanical and chemical digestion is introduced. Our teeth break down the food into smaller pieces as our salivary glands secrete saliva; breaking down the food (salivary amylase) through chemical digestion. While all this is occurring, the tongue moves the bolus (chewed food) to the back of the mouth to swallow. The bolus then travels through the pharynx into our esophagus (thanks to peristalsis) where it soon meets the cardiac sphincter. But sometimes the epiglottis forgets to close itself when we are swallowing and the bolus goes into our trachea instead. Which results in choking - uh oh! Now going back to the cardiac sphincter, this muscular valve allows the bolus to enter the stomach. The bolus is now called 'chyme'. As food passes into our stomach, it expands. The food travels through the pyloric sphincter into the duodenum. The liver, pancreas, and gall bladder are accessory organs. The liver receives all the blood returning from the digestive tract and processes protein, fats, and carbohydrates. It also produces bile, which emulsifies fats into the small intestine to aid in their digestion. Bile is stored into the gall bladder. Sodium bicarbonate (produced by the pancreas) neutralizes the chyme entering the small intestine from the stomach. The food in the small intestine is mixed around by the villi. Digestion and absorption of nutrients are complete by the time the contents reach the end of the small intestine. The large intestine absorbs most of the remaining water and compacts the residual matter as feces. The waste then enters the rectum and exits through the anus.
