Human diet and nutrition Flashcards
List the seven main components of a diet
Carbohydrates, proteins, lipids, iron, calcium, vitamins, water and fibre
What do carbohydrates, lipids and proteins aid in
They are all fuels for respiration
What are the function of carbohydrates and list some foods which contain carbohydrates
Fuel for respiration, Bread, potatoes, rice, cereal, fruit
What are the function of proteins and list some foods which contain proteins
Growth and repair of cells and tissues, Meat, eggs, quorn, fish, quinoa
What are the function of lipids and list some foods which contain lipids
Store for energy and insulation, Butter, cooking oil, cream, avocado
What is the function of Iron and list some foods which contain Iron
Forms the part of haemoglobin which binds
to oxygen, Read meat, liver, spinach
What is the function of Calcium and list some foods which contain Calcium
Needed to form bones and teeth, Milk, dairy products, fish, fresh vegetables
What is the function of Vitamin A and list some foods which contain Vitamin A
Making a chemical in the retina and also protects the surface of the eye, Fish liver oil, liver, butter, carrots
What is the function of Vitamin C and list some foods which contain Vitamin C
Needed for cells and tissues to stick together, Fresh fruit and vegetables e.g. oranges
What is the function of Vitamin D and list some foods which contain Vitamin D
Needed to absorb Calcium and Phosphate
ions from food, Dairy products, oily fish
What is the function of Fibre and list some foods which contain Fibre
Fibre helps the movement of food through the intestine, Wheat, oats, anything with cellulose
What can a deficiency in iron cause?
Anaemia, fatigue, dizziness, shortness of breath and general tiredness
What can a deficiency in Calcium cause?
🅱endy 🅱one Syndrome (rickets), stunted growth, pain in bones
What can a deficiency in Vitamin A cause?
Night blindness and a damaged cornea
What can a deficiency in Vitamin C cause?
Scurvy - spongy swollen gums, loose teeth and scaly dry skin
What can a deficiency in Vitamin D cause?
Rickets caused by weak bones
What is water essential for?
Water is an essential solvent,l as it allows molecules to be dissolved in it (blood). Crucial for temperature regulation
What are the five stages of the alimentary canal?
Ingestion (taking food in the mouth and swallowing), digestion (breaking down food), absorption (absorbing said smaller food molecules), assimilation (using new molecules to build more in cells), egestion (pooping).
What organs are used in the alimentary system?
Mouth, oesophagus, stomach, liver, pancreas, colon, small intestine, large intestine, anus
Name the two types of digestion which occur in the mouth and stomach
Chemical and mechanical digestion
Define mechanical digestion
Breaking up food into smaller pieces, using the teeth in the mouth (mastication) and the stomach muscles in the stomach
Define chemical digestion
Using enzymes to break down small pieces of food into even smaller molecules. In the mouth, the enzyme is in the saliva.
Which enzyme is used for chemical digestion in the mouth and what does it break down
Amylase is used to break starch down into maltose
How is choking caused? (bolus, epiglottis)
The mass of food is lubricated by saliva and shaped into a small ball called a bolus. If this bolus goes down the trachea by mistake (epiglottis flap not blocking trachea) choking can occur.
What is the oesophagus
A long pipe, connects mouth to stomach.
How does a bolus get pushed down the oesophagus?
Peristalsis pushes the bolus down
Define peristalsis
Peristalsis - circular muscles contract and relax, forcing food down the oesophagus
Which enzyme is used for chemical digestion in the stomach and what does it break down and what’s special about the enzyme?
Pepsin breaks down proteins into polypeptides. Pepsin works best in an acidic pH, which is why it’s in the stomach
What two stages of the alimentary system occur in the small intestine?
Digestion and absorption
Name the two parts of the small intestine and name which stage happens where
In the duodenum, digestion occurs. In the ileum, absorption occurs
Which enzymes are released into the duodenum and what do they break down?
Amylase breaks down starch into maltose, maltase breaks down maltose into glucose, lipase breaks down lipids into 3 fatty acids and glycerol and typrsin breaks down polypeptides into amino acids.
How do the enzymes work at their optimum conditions when stomach acid is present?
The stomach acid gets neutralised by bile, a neutral liquid.
What is bile and where does it come from in the body?
Bile breaks down fats and neutralises stomach acids to help with digestion. It comes from the liver and is stored in the gallbladder
Name three reasons as to why villi are good at aiding diffusion of molecules into the blood?
They have a large surface area, thin walls, high density of capillaries and a large blood flow through them. Also, microvilli increase surface area even more.
Name the two parts of the large intestine
Colon and rectum
What stage happens at the end of the alimentary canal?
Egestion occurs at the end of the alimentary canal
List the six enzymes and where they are made
Amylase in the saliva, pepsin in the gastric glands in stomach wall, amylase, lipase and trypsin form the pancreas and maltase in the small intestine lining
