Food and Digestion Flashcards
What is a balanced diet?
A balanced diet means eating the right types of food in the right amounts so that the body gets the nutrients it needs.
What are the seven nutrients?
- carbohydrates
- proteins
- fats
- vitamins
- minerals
- water
- fibre
What is carbohydrates function and nam a source?
- It is an immediate source of energy and you need lots of carbohydrates if you’re active and growing.
- Pasta, bread, rice, potatoes
What are lipids/fats used for? And name a source
- It is used for energy to make cell membranes. It is also used for energy if your body runs out of carbohydrates.
- fired bacon, nuts, dairy products
What is protein used for and name a source?
- It is for growth and repair and to make enzymes
- cooked salmon, nuts
What are minerals used for and name a source?
- They make body chemicals in small amounts
- white bread
- apples, nuts, cheese and milk which are all rich in calcium
What are vitamins for and name a source?
Vitamins in small amounts are used for cells to work properly and a source is kiwi
What is fibre for and an name a source
Fibre is to keep the bowels working properly and it helps to move food through your digestion
- chilli con carne
- fruit, vegetables, cereal, brown rice, brown bread, wholegrain bread
What is water used for?
It is used for chemical reactions to occur as water is where all the chemical reactions in your body take place and it is for transport
Which food has a high calorific content?
Fried bacon
Which food has a low caloric content?
Carrots and broccoli
What nutrient type do you think contributes most to the amount of calories a food has?
Fat
What food would you eat if you had an iron deficiency?
White bread, Burger King burger, chilli con carne, corned beef and brown bread
How do you test for starch.
Iodine
A dropping palette is used
In the test for starch what is the starting colour and what is the positive result.
Starting colour: brown
Positive result: black
How do you test for sugar and glucose?
It’s the benedicts test + warm water
The test tube used it put in hot water
What is the starting colour and the positive result for the test for sugar/glucose?
Starting colour: blue
Positive result: brick red
How do you test for protein?
Biuret (0.1M sodium hydroxide solution and 0.01M copper(II) sulfate solution) + warm water
The test tube used is put in hot water
How do you test for fats/lipids?
Alcohol
Two pipettes of alcohol + one pipette of water
Wait for the layers to separate
What is the starting colour and positive result for lipids and fats?
Starting colour: colourless
Positive result: the top layer goes cloudy
Name the parts of the digestive system
- tongue
- mouth
- salivary gland
- epiglottis
- trachea
- oesophagus
- gull bladder and bile duct
- liver
- pyloric sphincter
- large intestine
- appendix
- diaphragm
- stomach
- pancreas
- small intestines
- rectum
- anus
What is the stomach?
Muscular bag filled with gastric juice (a mixture of hydrochloric acid, mucus and enzymes e.g. protease breaks down proteins to amino acids). The stomach has a very strong lining to stop the strong acid from harming the stomach.It mechanically digests the food by churning it into a pulp called chyme. Food can be eaten in large quantities with gaps between meals but a steady flow of semi liquid food is allowed out of the stomach while large lumps of food cannot leave. Movement of food from the stomach into the duodenum is controlled by the small intestine which is a circle of muscle.
What is the mouth?
Your teeth help chop up food here. Saliva added here softens the food and has the enzyme amylase which is a type of carbohydrase which breaks down starch into sugar. Mastication happens here it is to crush down food inside your mouth; to chew food. This is mechanical chewing. It allows chemicals to get around everything. There is an enzyme called amalyse in the saliva which breaks down carbohydrates. The food mixes with saliva which contains mucus and lubricates the food making it easier to swallow.
What is the bile duct?
Bile is released here.
What is the gall bladder?
Bile is stored here.
What is the oesophagus?
A muscular tube which takes (semi-digested) food from the throat and pushes it down into the stomach. It moves food by waves of muscle contraction called peristalsis. The epiglottis covers the trachea to make sure food doesn’t enter.
What is the large intestine?
Water and body minerals are absorbed here and go back into the blood. The remains are formed into semi-solid faeces.
What is the liver?
Stores some nutrients, vitamins and minerals from digestion changes then from one form to another, and releases them into the blood according to the needs of the body. It also makes bile which removes toxins, breaks fat into tiny droplets and it neutralises the acid from the stomach so that the small intestine does not get harmed by the acid.
What is the rectum?
The end of the large intestine and the next part of the track is where the faeces are stored. Undigested food collects in the food, cellulose.
Herbivores have bacteria in their gut which can digest cellulose. Undigested food together with dead and living bacteria worn away from the gut lining is called faeces. Muscular contractions of the rectum forces the faeces out of the body through the anus.
What is the small intestine?
This is the site of maximum absorption.
Three liquids are added here bile, pancreatic juices and intestinal juice
-bile helps to neutralise the acid which was added to food in the stomach and is the best pH for enzymes to work. Bile also helps to break down fats.
-pancreatic juice contains enzymes e.g. lipase, carbohydrase, protease which helps to digest the food further
-intestinal juice also has the enzymes lipase, carbohydrase and protease. Finally the nutrients are small enough to pass through the lining and into the blood
What is the pancreas?
They make lots of enzymes e.g. lipase, carbohydrase and protease which help to digest the food further when released into the small intestine. This is the part of the body which produces the most enzymes. The pancreas secretes more NaHCO3 and many enzymes including amylase as salivary amylase would have been denatured by the acid in the stomach.
Absorb
The diffusion of particles into the body
Amylase
Enzymes found in saliva that breaks down carbohydrates
Amino acids
Product of digestion of protein
Bile
Alkaline, brownish-yellow fluid that is secreted by the liver, stored in the gallbladder. It is used to emulsify fats and break fats into smaller droplets so that they can be absorbed or broken down into fatty acids and glycerol. Bile also neutralises the acid on the food so that the small intestine is not harmed also so that the enzymes can work in the best possible conditions. Bile contains NaHCO3 and bile salts but no enzymes.
Denature
Process where the shape of an enzyme is changed so it no longer works. Heat and pH changes can denature enzymes
Digestion
The process where food is converted into smaller substances that can be absorbed by the body.
Emulsify
Break a large droplet into lots of smaller ones (usually fats and oils)
Enzyme
Substance in the body that chemically breaks up food into smaller substances. Each type of nutrient needs a specific enzyme
Fatty acids
Product of digestion of lipids
Glycerol
Product of digest of lipids
Gut
The entire length of tubing between the mouth and anus
Hydrochloric acid
Acid found in the stomach to kill bacteria