Digestive system
Apréndelo jugando
Responde estas preguntas para ganar energía, luego pesca y explora. Sin cuenta.
Apuntes de la lección
Overview of the Digestive System
- The digestive system breaks down food into small molecules that can be absorbed into the blood.
- It consists of many organs, each with a specific role in digestion.
- Enzymes are biological catalysts that speed up chemical reactions in digestion.
- Some bacteria live in the large intestine; they protect against harmful bacteria and help digest food.
Organs Food Travels Through
- Mouth: teeth mechanically break food; saliva contains amylase which breaks down starch.
- Oesophagus: walls squeeze to move food to the stomach.
- Stomach: muscular walls mechanically break food; contains hydrochloric acid to kill bacteria; protease breaks down proteins.
- Small intestine: contains villi with a large surface area for absorbing digested food into the blood.
- Large intestine: absorbs water from undigested food.
- Rectum: stores faeces (waste material) before it leaves through the anus.
Accessory Organs (Food Does Not Pass Through)
- Liver: produces bile to neutralise stomach acid.
- Gall bladder: stores bile and releases it into the small intestine.
- Pancreas: produces enzymes protease, amylase, and lipase (which breaks down lipids) and releases them into the small intestine.
Enzymes in Digestion
- Amylase (in saliva and from pancreas) breaks down starch (carbohydrates).
- Protease (in stomach and from pancreas) breaks down proteins.
- Lipase (from pancreas) breaks down lipids (fats).
- Enzymes work best at specific pH conditions; protease works best in acidic conditions in the stomach.
Absorption and Waste
- Digested food is absorbed in the small intestine via villi, which increase surface area for faster absorption.
- Water is absorbed in the large intestine.
- Undigested material forms faeces, stored in the rectum until eliminated.
Diagram
Diapositivas
Sign up free to view the lesson slides
Step through every slide for this topic — plus flashcards and revision notes — with a free account.
Preguntas de práctica
Vista previa gratis — 8 de 54 preguntas. Regístrate para verlas todas.
1.Which organ contains hydrochloric acid that kills bacteria?
Easy- AStomach
- BSmall intestine
- CLarge intestine
- DLiver
2.Where are villi found and what is their main function?
Easy- ASmall intestine; to absorb digested food
- BLarge intestine; to absorb water
- CStomach; to kill bacteria
- DOesophagus; to move food
3.In which organ is water absorbed?
Easy- ALarge intestine
- BSmall intestine
- CStomach
- DRectum
4.Which organ stores faeces before it leaves the body?
Easy- ARectum
- BAnus
- CLarge intestine
- DColon
5.Which enzyme breaks down starch, and where is it produced?
Easy- AAmylase; mouth
- BProtease; stomach
- CLipase; pancreas
- DAmylase; pancreas
6.What is the role of bile in digestion?
Easy- ANeutralise stomach acid
- BBreak down proteins
- CBreak down carbohydrates
- DAbsorb water
7.Enzymes are biological catalysts. What does this mean?
Easy- AThey speed up chemical reactions without being used up
- BThey are used up in reactions
- CThey slow down reactions
- DThey are only found in the stomach
8.Which organ produces enzymes that are passed into the small intestine, including protease, amylase, and lipase?
Easy- APancreas
- BLiver
- CGall bladder
- DStomach
Unlock all 54 questions, flashcards & more
Crea una cuenta gratis para ver todas las preguntas, las diapositivas, las tarjetas y los apuntes de repaso de este tema.