1.9 Digestive system Flashcards
What is the primary function of the digestive system in animals?
The breakdown of food and absorption of nutrients required for survival.
What are organisms that cannot synthesize their own nutrients called?
Heterotrophs.
What do heterotrophs need to consume to obtain nutrients?
Food.
What are the main components of a typical heterotroph’s diet?
- Proteins
- Carbohydrates
- Fats
- Nucleic acids
- Water
- Vitamins
- Minerals
What is the process of taking in and making nutrients from food called?
Nutrition.
What are the four main processes involved in nutrition?
- Ingestion
- Digestion
- Absorption
- Egestion
What type of digestion occurs in the mouth?
Both physical and chemical digestion.
What enzyme is released by salivary glands to aid in carbohydrate digestion?
Amylase.
What are essential nutrients?
Nutrients that cannot be made by the body and must be present in the diet.
What are the macromolecules and their functions?
- Carbohydrates: Energy supply
- Lipids: Insulation & energy reserve
- Proteins: Muscles & enzymes
- Nucleic Acids: Essential elements (Nitrogen & Phosphorus)
What is the role of enzymes in digestion?
They speed up chemical reactions in the cell without being used up.
What is the substrate in the enzyme example involving sucrose?
Sucrose.
What is the function of the epiglottis?
Closes over the trachea to prevent food from entering it.
What movement in the oesophagus helps to move food to the stomach?
Peristalsis.
What does the stomach produce to aid in digestion?
- Gastric juices
- Hydrochloric acid (HCl)
- Mucus
What is the role of the pancreas in the digestive system?
Produces alkaline fluid and pancreatic juices containing digestive enzymes.
What does bile produced by the liver help to digest?
Fat.
What is chyme?
The acidic fluid that passes from the stomach to the small intestine.
What is the purpose of villi in the small intestine?
Increase surface area for absorption.
What nutrients are absorbed by the villi?
- Glucose
- Amino acids
- Vitamins
- Lipids
What is the length of the large intestine?
About 1.5 metres.
What is the function of the rectum?
Short-term storage for faeces before egestion.
True or False: The small intestine is the shortest part of the digestive tract.
False.
Fill in the blank: The process of non-digested food leaving the body is called _______.
Egestion.
What connects the stomach to the small intestine?
Duodenum.
