B3 Organisation and the digestive system Flashcards
(42 cards)
Enzymes that break down substances are…
Catabolic
Enzymes that build substances from substrates are…
Anabolic
Explain what we mean by the ‘lock and key theory’
The ‘lock and key theory’ is an idea we use to explain the way enzymes work.
It suggests that the 3D shape of the active site of the enzyme is like a lock and can breakdown only one type of substrate just like the lock can only be opened by one shape of key.
Give another example of a food rich in fat.
There are many foods rich in food. Ice cream is obviously one but also;
butter, oil, lard, ghee, margarine, avacado, oily fish, nuts, peanut butter, sausages, chocolate, cream, greek yoghurt, flaky pastry and any fried food.
Give an example of a food which is a good source of carbohydrate.
There are lots of examples of a foods which are good sources of carbohydrates. You are correct if you suggested one of bread, rice, potatoes, crisps, chips, cakes, biscuits, sweets, pasta, fruits, fizzy drinks, syrup and honey.
How is the small intestine adapted for fast absorption of food?
The small intestine is adapted for fast absorption of food in 4 ways
- large surface area (villi)
- good blood supply
- wet
- thin wall
What is an organ system?
Organ systems are a collection of different organs which do a particular job in the body.
e.g. cadiovascular/ circulatory system (heart and blood)
digestive system (food breakdown and absorption)
the respiratory system (gaseous exchange)
Name a food rich in protein.
There are lots of great foods rich in protein. You are right if you said one of meat, fish, eggs, milk, cheese, yoghurt, nuts, beans, lentils, chickpeas, quinoa, whey protein, tofu, soya or quorn.
What are organs?
Organs are collections of different types of tissues with a special job to do
e.g. heart pumps blood, stomach digests food, liver breakes down chemicals
What do carbohydrases do?
Carbohydrases are digestive enzymes which break down carbohydrates to simple sugars.
What do lipases do?
Lipases break down lipids (fats) to glycerol and fatty acids.
What do our bodies use carbohydrates for?
Our bodies use carbohydrates for fuel for respiration.
Starch is a slow release fuel and and sugars such as glucose give us fuel quickly.
What do our bodies use fats for?
Our bodies use fats in many ways. You are right if you suggested one of
- as slow release energy,
- to store extra energy,
- to build cell membranes,
- to make hormones
- for insulation.
What do our bodies use proteins for?
Our bodies use proteins for growth and repair.
What do proteases do?
Proteases break down proteins to amino acids.
What does glandular tissue do?
Glandular tissue is made of lots of secretory cells. They release enzymes and hormones.
What happens in the digestive sytem?
The digestive system is an organ system in which food is digested and absorbed.
What 3 things happen in your small intestine?
3 things happen in your small intestine,
- bile is added to the food to help break fats into smaller droplets
- more enzymes (protease and lipase) are added to finish breaking down food
- the tiny food particles made cross the gut wall into the blood stream
What is a tissue?
(Not something you blow your nose on!)
A tissue is a group of cells with a similar structure and function.
What is amylase, what does it do and where does it do it?
Amylase is a carbohydrase enzyme which breaks down starch in the mouth and small intestine.
What is an enzyme?
Enzymes are biological catalysts. They are proteins which speed up specific reactions in living organisms.
What is an optimum pH or temperature of an enzyme?
An optimum pH or temperature of an enzyme is the pH or temp at which it works best/fastest.
What is metabolism?
The sum of all the reactions in a cell or the body
What is the acid secreted by the stomach?
The acid secreted by the stomach is hydrochloric (HCl).
It makes about 3 litres of it every day!
