Organisation Flashcards
(118 cards)
Define cells.
Building blocks of all living things.
Define tissues.
Group of similar cells working together to carry out a specific function.
Define an organ.
Different tissues working together to carry out a specific function.
Define an organ system.
Organs working together to carry out a specific function.
What happens in physical (mechanical) digestion?
Food is broken down into smaller pieces. This increases surface area of the food therefore facilitating chemical digestion by the enzymes.
Occurs in two ways:
- chewing action in mouth with help from the teeth.
- peristalsis = walls of the oesophagi, stomach and intestine.
There is no chemical change of food.
What happens in chemical digestion?
Breaking down of large insoluble molecules into smaller soluble molecules.
Enzymes are required so food is chemically changed.
What is the function of the gall bladder in the digestive system?
Stores bile before releasing it into the duodenum.
What is bile?
a substance produced by the liver. It emulsifies fats to prepare them for digestion.
What is the role of the mouth in digestion?
Food enters, physical digestion begins.
What is the purpose of salivary glands in the digestive system?
Produce saliva and amylase (breaks down starch)
What is the purpose of the oesophagus in the digestive system?
Transfers food to stomach from mouth by peristalsis.
What is the purpose of the stomach in the digestive system?
Mixes food with acid and enzymes - food broken down by acid and enzymes.
What is the purpose of the small intestine in digestion?
Absorbs nutrients and minerals from food. Also digests food using enzymes.
What is the purpose of the large intestine in the digestive system?
Absorbs water.
what is the purpose of the liver in the digestive system?
Creates bile which is then transported to the gall bladder. Liver also neutralises acid in the small intestine and emulsifies fat.
What are the food groups?
Carbohydrates Fats Proteins Minerals Vitamins Fibre Water
What are broken down carbohydrates called?
Simple sugars
Describe the chemistry of lipids.
They are made of 3 molecules of fatty acids and one molecule of glycerol. (The fatty acids three molecules can change but there will always be one molecule of glycerol.)
What is the subunit of proteins?
Amino acids.
What is the purpose of carbohydrates?
Energy to our bodies.
What is the purpose of fat?
Energy, insulate against cold
What is the purpose of proteins?
Growth and repair.
What is the purpose of minerals?
Help normal functioning of the body.
What is the purpose of vitamins?
Protect from sickness