Chapter 4 - Food And Digestion Flashcards
7 things our bodies need for a balanced diet
- carbohydrates
- lipids
- proteins
- minerals
- vitamins
- fibre
- water
What are carbohydrates
- our main source of energy for the body
- needed by the body to carry out respiration
4 examples and sources of glucose
Glucose - found in many sweet things like fruits and also veg
Fructose - found in fruit
Lactose - found in diary products like milk
Sucrose - found in sugar cane
What is tooth decay
Caused by sugars
When bacteria feeds on the sugar and makes acids
These acids will start to break down enamel on the teeth until cavities start to form
What is starch
- a very large and insoluble molecule
- very long molecule known as polymer
- made up of hundreds and hundreds of glucose molecules joined up together
- broken down to glucose by amalayse contained in your saliva
Found in bread, pasta, potatoes and other plant tissues
What is cellulose
Another type of carbohydrates found in plants
Our bodies cannot digest cellulose so it goes straight through
We describe it as a source of fibre
3 main reasons we need food for
- energy
- growth and repair tissues
- to help fight diseases and keep our bodies healthy
2 types of carbohydrates
glucose - C6H12O2 -> monosccharides
starch (plants) / glycogen (animals)-> insoluble, polysaccharides
elements present in carbohydrates
carbon
hydrogen
oxygen
sources of lipids
meat butter cheese milk eggs and oily fish -> animal fat
nuts, avocado , seeds, soy -> plant fat
what are lipids
10 % of the bodys mass
essential part of the structure of cells
deposited around the body as a source of long term energy
fat layer under skin acts as insulation
fat around organs protects them from mechanical damage
difference between fats and oils
fats are solid and saturated
oils are liquid and unsaturated
elements present in lipids
hydrogen
carbon
oxygen (but less o2 than in glucose)
why are saturated especially unhealthy
causes heart disease
especially from cholesterol
what are proteins
make up about 18% of bodys mass
all cells contain proteins as we need it for growth and repair of cells
foods rich in proteins are meat fish cheese and eggs.
what is kwashikor
a disease caused by protein deficiency.
symptoms include weight loss, swollen belly (from fluid collecting in the tissues), poor muscle growth, general weakness and flaky skin
what are proteins made up of
amino acids
20 of them
all of them contain carbon hydrogen, oxygen and nitrogen (2 also contain sulphur)
like letters going them up makes ‘words’
what are essential amino acids
humans can make half of the amino acids but the other 10 called ‘essential’ amino acids and we have to eat foods that contain these.
what do we need iron for
and sources of iron
needed to make haemoglobin which is found in red blood cells and enables them to carry oxygen
red meat dried apricots dark green veg , nuts and seeds
name an iron deficiency and symptoms
ANAEMIA
- weakness or fatigue
- shortness of breath
- pale : skin, mucosal linings and nail beds
what do we need calcium for
sources of calcium
needed to make bone grow properly and harden fully
to make and maintain teeth
fish with self edible bones such as salmon and sardines
dairy products
name a calcium deficiency and symptoms
RICKETS
poor bone development
deformed bones that are soft
sources of vitamin d
sunlight
fish liver oil
eggs
what do we need vitamin d for and what is it deficiency disease
needed for maintaining bone structure
RICKETS
what do we need vitamin C for and what is its deficiency disease
needed to make connective tissues , which is like the glue that bonds cells together
e.g. in walls of blood vessels , skin and lining of the body
sources of vit c and deficiency disease
fruit and veg
SCURVY
