Flashcards in Human Nutrition and Biological molecules Deck (36):
Mouth function (2 points)
Salivary glands produce amylase enzyme in the saliva
Teeth break down food
Connects mouth and stomach
Gall Bladder function
Large intestine function
Absorbs excess water from food
Stomach function (2 points)
Breaks food up
Produces pepsin (protease enzyme)
Food or drink enters mouth
Break down of large, insoluble molecules to small, soluble molecules
Example of mechanical digestion
Example of chemical digestion
Moving molecules through intestine walls to blood
Digested molecules move into body cells and become part of the cells
Undigested material form faeces
Produces protease, amylase and lipase enzymes
Small intestine function
Produces protease, amylase and lipase enzymes to complete digestion
Describe process of Peristalsis
Muscular tissue that goes down to down to alimentary canal is used to squeeze balls of food, boluses, through gut. This squeezing action ,makes the circular muscles contract, is called peristalsis.
Why can starch, protein and fat not pass through walls of digestive system?
Too big and insoluble
What do digestive enzymes do
Break down big molecules into smaller ones
What does amylase do?
Converts starch into maltose
What does maltase do?
Converts maltose into glucose
What does protease do?
Converts proteins into amino acids
What does lipases do?
Converts lipids into glycerol and fatty acids
2 functions of bile
Neutralises stomach acids
Emulsifies fat (breaks into tiny droplets)
Where is bile produced?
Where is bile stored?
Where is bile released to?
Describe and explain how and why bile neutralises stomach acids
HCl in stomach makes pH for enzymes in small intestine too acidic to work. Bile is alkaline - it neutralises acid and makes pH alkaline as enzymes work best in alkaline conditions
Explain how bile makes digestion faster
Bile breaks fat into tiny droplets. This makes bigger surface area for lipase, increasing the rate of digestion
3 ways villi are adapted for absorption
Millions of them - more absorption
Single permeable layer of surface cells and good blood supply to assist absorption
Each cell on villus has its own microvilli, to increase surface area for absorption
What are carbohydrates made up of?
Glucose and maltose, ect, joined together
What are proteins made up of?
Chains of amino acids
What are lipids made up of?
Fatty acids and glycerol
Describe how to test for glucose
Add benedicts reagent to sample and heat
Make sure doesn't boil
If glucose present, sample goes from blue to brick red
Describe how to test for starch
Add iodine solution to sample
If starch present, sample goes from browny-orange to black