Nutrition Flashcards
Carbohydrates
Examples
Functions
What happens if there is a lack of this?
Examples include pasta, rice, potatoes and bread
Function:
Main source of energy
If there is a lack - ketosis occurs when you don’t have enough sugar for energy. This means that your body breaks down stored fat which causes ketones to build up.
Protein
Examples
Functions
What happens if there is a lack of this?
Examples include meat, fish, eggs and beans
Function:
Growth and repair of cells
If there’s a lack - muscle cramping, weakness and soreness, kwashiorkor
Lipids
Examples
Functions
What happens if there is a lack of this?
Examples include cheese, butter, nuts and oils.
Function:
Second source of energy
Provides insulation and storage
If there’s lack - dry and scaly skin and won’t make cell membrane
Vitamin A
Examples
Functions
What happens if there is a lack of this?
Examples include milk, dairy products and oily fish.
Function:
Good vision
Healthy skin
Vitamin C
Examples
Functions
What happens if there is a lack of this?
Examples include citrus fruits and leafy green veg
Function:
Heal wounds
Maintain healthy connective tissue
If there’s a lack of it can lead to scurvy and loss of teeth
Vitamin D
Examples
Functions
What happens if there is a lack of this?
Examples include eggs, oily fish and margarine
Function:
Maintain healthy bones and teeth
If there’s a lack it can lead to rickets and bone pain
Calcium
Examples
Functions
What happens if there is a lack of this?
Examples include salt, milk, cheese and eggs
Function:
Healthy bones and teeth
If there’s a lack - weak bones and teeth, poor clotting of blood and rickets
Iron
Examples
Functions
What happens if there is a lack of this?
Examples include liver, red meat and nuts
Function:
Needed to produce haemoglobin which is found in red blood cells
If there’s a lack - anaemia (tired and weak).
Water
Examples
Functions
What happens if there is a lack of this?
Examples include food and drinks
Function:
Needed for chemical reactions
If there’s a lack it can lead to death and dehydration
Dietary fibre
Examples
Functions
What happens if there is a lack of this?
Examples include fruits, veg and cereals
Function:
Keep digestive system healthy
If there’s a lack it can lead to constipation
Energy requirements
Different groups of people need different nutrients at different times in their lives. The energy a person needs depends on things like:
Activity level - active people need more energy than people who sit about all day
Age - children and teens need more energy than older people as they need energy to grow and they are generally more active
Pregnancy - pregnant women need more energy than other women as they have to provide the energy their babies need to develop.
Babies (4-6mnths) need less energy as they haven’t hit puberty yet and they are small still
Children (8yrs) are still growing but need more than babies and boys are more active and so need more energy.
Teenagers (15yrs) - rapid growth at this age. Need ,ore energy as they are going through puberty. However girls need less as they have already gone through puberty.
An adult who sits in a office needs less energy to someone lo,e a builder as they are more active
Elderly people need less as they have stopped growing and tend to be less active.
Digestive system diagram
On OneNote
Salivary glands
Produces saliva containing amylase
Digests starch
Mouth
Food is chewed up by teeth and swallowed
Saliva breaks down the starch to maltose (sugar).
Oesophagus
Muscular tube which moves ingested food to the stomach by peristalsis
Gall bladder
Stores bile before releasing it
Stomach
Churns the food
Contains the enzyme pepsin and hydrochloric acid to kill bacteria
Pancreas
Produces protease, amylase and lipase enzymes and releases them into the small intestine
Small intestine
Where food is mixed with bile and digestive enzymes
Produces protease, amylase and lipase
Large intestine
Where water is reabsorbed. Also called colon.
Rectum
Where faeces are stored
Anus
Where faeces leave the alimentary canal
Duodenum
Where food comes into contact with bile
ileum
Where absorption of the food molecules take place
Peristalsis
Peristalsis are wave like movements that are caused by contractions of the muscles that squeeze the food. Fibre in the food keeps the food bulky and soft making peristalsis easier.
What was enzymes?
Enzymes are biological catalysts which speed up reactions. The Pancreas produces enzymes
Amylase
Where it’s found in the alimentary canal
Substrate - what they digest
Product what it turns into
It’s found in the salivary glands
The substrate is starch
The product is maltose
Maltase
Where it’s found in the alimentary canal
Substrate
Product
It’s found in the small intestine
Substrate - maltose
Product - glucose
Protease
Where it’s found in the alimentary canal
Substrate
Product
Where it’s found - stomach, pancreas and small intestine
Substrate - protein
Product - amino acids
Lipase
Where it’s found
Substrate
Product
It’s found in the pancreas and small intestine
Substrate - fat (lipids)
Product - glycerol and fatty acids
The role of bile
Bile is a substance made by the liver and stored in the gall bladder. It flows onto the small intestine via the bile duct.
Bile salts emulsifies fats (lipids) meaning it breaks down large droplets of fat into small droplets of fat so there is an increased surface area for lipase to break down the fats into glycerol and fatty acids.
Sodium hydrogen carbonate in bile neutralises stomach acid and so provides the right pH for pancreatic enzymes to work.
Ingestion Digestion Absorption Assimilation Egestion
Definitions
Ingestion - taking food into the digestive system
Digestion - breaking down large molecules into simple ones
Absorption - of small digested molecules into the blood
Assimilation - converting food molecules into other useful molecules in the body
Egestion - removal of undirected material from the body.
How vili is adapted for the absorption of products of digestion
- Big surface area so it can absorb lots of molecules at once.
- Once cell thick and a single leader of epithelial cells so diffusion can occur
- Rich capillary network to take the nutrients away and transport around the body which helps to maintain a steep concentration gradient.
- Has lacteal in the centre which is connected to a lymph vessel to help transport fatty acids and glycerol around to the cells
