2e Nutrition Flashcards
What does a ‘balanced diet’ mean?
To eat a variety of different foods
What does malnourished mean?
Bad nourished - someone who isn’t getting enough important nutrients
What are carbohydrates for?
Main source of energy in our diet
Examples of carbohydrates
Simple sugars
rice
potato
pasta
spaghetti
bread
starch - complex
What are proteins for?
Growth and Repair
Examples of Proteins
milk
cheese
meat
chickpeas
fish
What are lipids for? (fats and oils)
Insulation
Store of energy
Protect vital organs
Examples of Lipids
Avocado
margerine
butter
oil
What are vitamins for?
Keep us healthy
Examples of Vitamins
Carrots - A
Oranges - C
Sunlight - D
Tablets
Fish - D
Daisy - D
Cereal - D
What are minerals for?
Keep us healthy
Examples of minerals
Spinach
Dark chocolate
Milk
What is water for?
keep us hydrated
Examples of water
Water
Fruits and veg
Juices
What does Fibre do?
- Helps food go through your gut
- Prevents constipation
- Prevents bowel cancer
Examples of Fibre
Wheat
Oats
Sweetcorn
Grains
Vegetables
Brown rice
What can fat and high sugar diet lead to?
Obesity
What can only eating one type of food lead to?
Not enough variety to give a balanced diet
What can a high salt diet lead to?
Can increase blood pressure leading to heart attacks and strokes
What can a diet with no vegetables lead to?
Not enough vitamins to keep the body healthy
Do we all need the same diet?
No, it depends on your age, and it could also depend on how active you are during the day, how much energy you use
Children need more protein because they are growing
What is Anaemia?
Nutrient lacking: iron
Symptoms: skins becomes pale
lips and nails become dull and colourless
feel weak
feel tired
What foods could help treat this disease?: green, leafy vegetables eg. cabbage and spinach
meat
apples
beans
dry fruits
What is scurvy?
Nutrient lacking: Vitamin C
Symptoms: Lethargy
skin spots
bleeding gums
loss of teeth, fever and death
What foods could help treat this disease?: oranges, citrus fruits
cabbage
What is rickets?
Nutrient Lacking: Vitamin D
Symptoms: muscles and bones become soft
can cause permanent disabilities in children
What foods could help treat this disease?: foods rich in Vitamin D
Milk
Fish
Meat
Butter
What is night blidness?
Nutrient lacking: Vitamin A
Symptoms: impossible to see in dim light
completely blind when night falls
skin becomes dry, eyes become dull and listless
What foods could help treat this disease?: diet rich in Vitamin A
Carrots
Fish
Fruits
Milk
Butter
What is the IV, DV and CV?
IV - thing we are changing
DV - what you measure
CV - what stays the same
What is the equation for energy?
Energy (J/g) = rise in temperature x volume of water x 4.2/ mass in g
How should the experiment be improved?
- There should be more insulation
- To measure the volume of the water accurately using a syringe
- Maybe don’t use a boiling tube
- The most ideal way is a bomb calorimeter which takes all of these into account
- Use a digital thermometer to measure the temperature
Why were our results so far off the actual values?
- No insulation around it so more energy escaped into the surroundings
- Some energy stayed on the boiling tube so it didn’t reach the water
- The water was black which was soot and some of the crips was still left because of incomplete combustion
What is the role of the mouth?
- Food is ingested through the mouth, the mouth is the first organ of the alimentary canal
- The teeth and tongue break down the food into smaller pieces
- Saliva moistens the food but also contains enzymes to begin digestion of starch
Bolus - tongue turns food into ball
amylase enzyme - which starts to break down enzymes
What is the role of the oesophagus?
The oesophagus is a soft, muscular tube that moves food from the pharynx to the stomach
The food is moved by muscular contractions called peristalsis
Each lump of swallowed food is called a bolus
What is the role of the stomach?
The stomach has a lining that’s tough enough to hold up in the highly acidic environment needed to break down food.
You have hydrochloric acid in your stomach
The churned up food is now called chyme
What is the role of the small intestine?
The small intestine is called small because of its width, not its length. It’s actually much longer than the large intestine. The small and large intestines form one continuous tube
Digestion is completed here, the digested food is absorbed into the blood
What is the role of the large intestine?
The large intestine consists of three parts - the cecum, colon and rectum
Water and some vitamins are absorbed here
What is the role of the rectum?
It is where your food is stored before excretion
What is the role of the anus?
The anus is the exit point of the alimentary canal. Faeces is egested here
What is the role of the pancreas?
The pancreas makes hormones (including insulin) to regulate the blood glucose level. It also makes enzymes break down food in the intestines
What is the role of the liver?
- Produces bile which is passed into the gallbladder and then into the small intestine to emulsify lipids
- (Excess amino acids are broken down here)
- (Excess glucose is stored as glycogen here)
What is the role of the gallbladder?
The gallbladder is a small pouch that stores bile. The gallbladder releases bile into the duodenum (small intestine) to help digest the fats in the food you eat
What is digestion?
Breaking down large food molecules into smaller molecules
happens in small intestines, stomach and mouth
What is peristalsis?
Muscular contractions that move food along the alimentary canal
Happens in the oesophagus
What is ingestion?
Taking food into the body
happens in the mouth
What is absorption?
The movement of digested food molecules from the gut into the blood stream
happens in the small intestine or large intestine
What is egestion?
Removal of faeces from the body
happens in the anus or rectum
What is assimilation?
The process by which simple food molecules are made into complex molecules in the body
What is digestion (definition)?
Digestion is the process of breaking down food to convert large insoluble food molecules into smaller soluble ones
or
The breakdown of food; physical or mechanical digestion breaks food down into smaller pieces (such as by chewing and the muscular action of the stomach) ready for chemical digestion by enzymes
Why is digestion necessary?
The large molecules are broken down into small molecules so they can be passed through the walls of the small intestine so they can be dissolved into the blood stream.
What are the adaptations of the villi?
- Found in the small intestine; has a large surface area. Good blood supply so the supplies can move effectively into the blood.
- They are well supplied with blood capillaries, taking absorbed food molecules from the small intestine to the rest of the body and supplying fresh blood - this keeps the concentration gradient between the digested food in the intestine and the cells in the body as high as possible.
- They are covered in a thin layer of cells so that digested food molecules do not have to travel far to be absorbed into the body and into the blood in the capillaries in the villi.
- Contain lacteals that carry lipid droplets separate from the rest of the food molecules because lipids do not dissolve well in blood
What do the villi and microvilli provide?
They provide an enormous surface area for absorption
Why is the wall of the villi very thin?
It’s thin so that the digested food has a short distance to travel to the bloodstream
Why does the villi contain a blood network of capillaries?
It’s to keep a high concentration gradient of nutrients between the small intestine and blood.
Why do villi contain lacteals?
So that they can carry fat droplets as they do not dissolve well in blood.
What is chemical digestion?
The breakdown of large food molecules into smaller ones using digestive enzymes
What is physical/mechanical digestion?
Occurs mainly in the mouth, where food is broken down physically into smaller pieces by the teeth, and in the stomach, where food is churned by the muscular action of the stomach wall
What breaks down carbohydrates?
- Carbohydrates are chains of identical sugar molecules. The digestive enzymes called carbohydrases break the chemical bonds in each carbohydrate chain
- One example of a carbohydrase which digests starch is amylase and is found in 3 places in the body, salivary glands, pancreas and small intestine
- There is another carbohydrase enzyme called maltose
Produced by mouth, pancreas and small intestine and converts carbohydrate into sugar molecules or simple sugars
What breaks down proteins?
- Proteins are made up of amino acids. There are 20 different types of amino acids.
- Proteins are digested by digestive enzymes called proteases. These enzymes work in an acidic environment to break proteins into smaller amino acids
- Protease enzymes are found in stomach, pancreas and small intestine
Protease is produced by stomach, pancreas and small intestine converts proteins into amino acids
What breaks down lipids?
Lipids are made up of glycerol and fatty acids
- Lipids are digested by digestive enzymes called lipases
- Lipase enzymes are found in the pancreas and small intestine
Lipase is produced by pancreas and small intestine and converts fat into fatty acids and glycerol
Fats are digested in 2 stages:
1) Bile (released from the gall bladder) lets fat “mix” with water by breaking the fat into smaller droplets. This is called emulsification
2) The digestive enzyme lipase breaks each fat molecules into the smaller glycerol and fatty acid molecules
What is bile produced in?
It is made in the liver and stored in the gall bladder. It lets fat mix with water
Converts fat into smaller droplets
emulsifies lipids
neutralises stomach acids
