Levels of Organisation

Small intestine: absorbs nutrients from food

Large intestine: absorbs water from food

Lungs: transports oxygen to the blood and removes carbon dioxide from the blood

Brain: controls thoughts, memory, and other organs

Kidneys: filters the blood and produces urine

Bladder: stores urine

Stomach: helps digest food

Heart: pumps blood around the body

Liver: removes poisons from the blood

Organelle: specialised structures in a cell

Cell: the smallest structural unit of an organism

Tissue: a group of similar cells with a similar function

Organ: a group of tissues working together with the same function

Organ sytem: a group of organs working together with the same function

Organism: a group of organ systems working together

Muscular tissue: contracts + relaxes to cause movement.

• e.g skeletal muscle
• cardiac muscle

Glandular tissue: secretes substances.

• e.g pancreas secretes insulin
• stomach, small intestine and pancreas secretes enzymes

Epithelial tissue: covers & lines organs, keeping them together.

Carbohydrates are made up of units of sugar. Simple sugars turns Benedict's solution from blue to red.

Complex carbohydrates contain long chains of simple sugars. Starch turns iodine from yellow to blue-black.

Lipids consists of three molucles of fatty acids bonded to a molecule of glycerol. Sudan III creates a red layer of fat.

Protein is made up of long chains of amino acids. Protein turns Biuret reagent from blue to purple.