The Story Of A Cheese Sandwich
The Story of a Cheese Sandwich.
A cheese sandwich is made up of – well, bread and cheese. The bread’s made of carbohydrates and fibre and the cheese of fat, protein and calcium.
First the sandwich is chewed with our teeth; the incisor teeth and canine teeth bite it into chunks. The premolar and molar’s grind the chunks of food into much smaller pieces. Saliva’s produced that helps the food become a paste. Here, the amylase enzymes turn the starch molecules (from the bread) into maltose – which is used by cells to give us energy.
The bolus (lumps of food) squeezes past the epiglottis then down the oesophagus which connects the throat to the stomach.
The bolus then enters the stomach where gastric juices are produced by the walls of the stomach. The protease, pepsin, starts the digestion of proteins to smaller molecules called polypeptides. Hydrochloric acids break the food down further and kills all the bacteria. The stomach then churns everything together (food, gastric juices and hydrochloric acid) into a squishy mush; this process is called chyme.
A ring of muscle – the pyloric sphincter opens to let the food past into the duodenum which is the first part of the small intestine.
Protease and amylase enzymes again break down the food until the nutrients are small enough to pass through the villi through which they enter the bloodstream. This process is called absorption. The nutrients travel with oxygen in the blood around the body to each of the cells. The cells produce energy using the oxygen and nutrients. The blood then carries the carbon dioxide to the lungs where it’s exhaled. But for efficient absorption, the inside wall of the small intestine needs to be thin, with a really big surface area. If the small intestine has a thick wall and a small surface area, a lot of the digested food might pass out of the body before getting a chance to be absorbed. Which is why there are tiny finger like projections lined in the inside of the small intestine
A cheese sandwich is made up of – well, bread and cheese. The bread’s made of carbohydrates and fibre and the cheese of fat, protein and calcium.
First the sandwich is chewed with our teeth; the incisor teeth and canine teeth bite it into chunks. The premolar and molar’s grind the chunks of food into much smaller pieces. Saliva’s produced that helps the food become a paste. Here, the amylase enzymes turn the starch molecules (from the bread) into maltose – which is used by cells to give us energy.
The bolus (lumps of food) squeezes past the epiglottis then down the oesophagus which connects the throat to the stomach.
The bolus then enters the stomach where gastric juices are produced by the walls of the stomach. The protease, pepsin, starts the digestion of proteins to smaller molecules called polypeptides. Hydrochloric acids break the food down further and kills all the bacteria. The stomach then churns everything together (food, gastric juices and hydrochloric acid) into a squishy mush; this process is called chyme.
A ring of muscle – the pyloric sphincter opens to let the food past into the duodenum which is the first part of the small intestine.
Protease and amylase enzymes again break down the food until the nutrients are small enough to pass through the villi through which they enter the bloodstream. This process is called absorption. The nutrients travel with oxygen in the blood around the body to each of the cells. The cells produce energy using the oxygen and nutrients. The blood then carries the carbon dioxide to the lungs where it’s exhaled. But for efficient absorption, the inside wall of the small intestine needs to be thin, with a really big surface area. If the small intestine has a thick wall and a small surface area, a lot of the digested food might pass out of the body before getting a chance to be absorbed. Which is why there are tiny finger like projections lined in the inside of the small intestine