8a Food Flashcards
What is the digestion system
It’s a system where the process of digestion occurs, which is the breaking down of food to release energy
How does digestion happen
First your teeth grind the food and then in saliva an enzyme called amylase breaks down carbohydrates.
Food travels by a muscular contraction and relaxation called peristalsis in the Oesophagus
The stomach contains hydrochloric acid which creates a low ph and kills harmful bacteria and serves as an optimum environment called protease which digests proteins .
In the small intestine digestion of proteins , carbohydrates and fats happen by enzymes called protease , carbohydrase and Lipase which are secreted by the pancreas . Bike juice form the liver is also secreted into the small intestine which emmulsifys the fat molecules
The large intestine then absorbs water from the undigested food
Undigested food which are stored as feces in the rectum are digested through the anise
How is the small intestine adapted to absorbing food .
It has small finger like projections called villi in its walls which provide s large pr sureface area . Villi have blood capalliries which carry the glucose in them . Walls of small intestine spare very thin so that the glucose can be absorbed
Large molecules can not be absorbed
What are carbohydrates, lipids and proteins when broken down
C-glucose
L- fatty acids + glycerol
P- amino acids
What causes malnourishment
A unbalanced diet
What can happen if you are overweight
Obesity leading to heart disease and diabetes
What can happen if you are underweight
Poor immune system
Lack of energy and in extreme cases anorexia
What are enzymes
Biological catalysts - speeds up digestion without being used up
What is bile and what does it do
Bile is produced by the liver and secreted into the small intestine and breaks( emmulsifies) the lipids into small droplets so tha5 lipase can work easily
What is a balanced diet
The right amount of nutrients in a diet
What is a healthy diet
A balanced diet
Name the nutrients with function
Carbohydrate - provide energy Protein- growth and repair Lipids - provide energy Fibre - provides bulk (helps stop constipation ) Victims - keep you healthy Minerals - keep you healthy Water - needed for cells and body fluids
How to test for carbohydrates
Starch test
Iodine
Lipids rest
Ethanol
Turns from colourless to cloudy
Protein test
Biuret test
