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17 Cards in this Set
- Front
- Back
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What are many of the molecules in our food? |
Polymers-large, complex molecules composed of long chains or monomers-small, basic molecular units. |
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What are the monomers in the polymers: carbohydrates and proteins? |
Proteins-amino acids-carbon, hydrogen, oxygen and nitrogen Carbohydrates-monosaccharides-carbon, hydrogen and oxygen |
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What is the problem with the polymers in our food? |
They are insoluble-they can't be directly absorbed into our bloodstream and assimilated into new products |
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How do we overcome this? |
The polymers have to be hydrolysed into smaller, more soluble molecules |
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What is added to hydrolyse the polymers |
Water |
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When and how does hydrolysis happen? |
It happens during digestion as it is catalysed by digestive enzymes |
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What is the function of the mouth/salivary glands? |
There are 3 main pairs of salivary glands-they secrete saliva consisting of mucus, mineral salts and salivary amylase. Salivary amylase breaks down starch into maltose. Saliva also helps lubricate food, making it easier to swallow |
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What is the function of the oesophagus? |
It is the tube that takes food from the mouth to the stomach using waves of stomach contractions called peristalsis. Mucus is secreted from tissues in the walls, to lubricate the food's passage downwards |
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What is the function of the stomach |
it is a small sac with lots of folds, allowing it to expand. The entrance and exit of the stomach are controlled by sphincter muscles. The walls produce gastric juice which consists of HCL, pepsin and mucus, helping break down food. |
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How do the pepsin and HCL help? |
Pepsin hydrolyses proteins, into smaller polypeptide chains and it only works in acidic conditions-provided by the HCL. Peristalsis of the stomach turns food into an acidic fluid called chyme. |
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What is the function of the pancreas? |
Releases pancreatic juice into the duodenum through the pancreatic duct. This juice contains amylase, trypsin, chymotrypsin and lipase. It also contains sodium hydrogencarbonate, which neutralises the acidity of the HCL from the stomach. |
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What is the function of the small intestine |
It consists of two parts- the duodenum and the ileum. Chyme is moved along the small intestine by peristalsis. |
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What is the function of the duodenum |
In the duodenum, bile (alkaline) and pancreatic juice neutralise the acidity of the chyme and break it into smaller molecules. |
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What is the function of the ileum |
In the ileum, soluble molecules (eg, glucose and amino acids) are absorbed through structures called the villi that line the gut wall. Molecules are absorbed by diffusion, facilitated diffusion and active transport |
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What is the function of the large intestine? |
AKA the colon, absorbs water, salts and minerals. It has a folded wall-provides large SA for absorption. Bacteria that decompose some of the undigested nutrients are found in the LI. |
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What is the function of the rectum? |
Faeces are stored in the rectum and then pass through the sphincter muscles at the anus during defecation. |
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What is the function of the gall bladder?
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It stores bile, which emulsifies the fats turning them into smaller droplets to give it a larger SA for enzymes to work on
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