Unit 1 - AOS2 - Digestive system Flashcards
3 points that make a mammal
- Give birth to live young
- Have the ability to produce milk to feed to young
- have hair or fur
Autotroph
Create their own energy through photosynthesis or chemosynthesis (plants at the bottom of the ocean)
Heterotroph
Cannot create their own energy,
- Therefore, get their energy through consuming other autotrophs or heterotrophs
Herbivore
Eat plants
- Therefore eat a lot of cellulose (carbohydrate that forms plant cell walls)
- e.g. horse
Carnivore
Eat meat
- gut produces enzymes to break down protein (protease)
- e.g. dog
Omnivore
Eat both plants and animals
- Share features from herbivores and carnivores
- e.g. humans
Carbohydrates
- Is broken down to glucose and stored as polysaccharide and glycogen in liver and muscles of animals
- Glucose breaks down to produce ATP during cellular respiration
Fats
- required for cell membrane, hormones and vitamin
- excess fat is stored under the skin tissue and surrounding organs
Protein
- Required for protein synthesis
- Stored as amino acids
essential amino acids
the 9 amino acids that humans cannot make
- Found in milk, effs and meat and cannot be stored.
Vitamins
- Organic (made from carbon and/or hydrogen and oxygen)
- required to make particular enzymes
Minerals
- inorganic
- Obtained through diet (calcium, potassium, iron, magnesium, sodium)
Chemical digestion
uses enzymes which break down complex compounds into simple compounds
the 3 main kinds of digestive enzymes
Amylase:
- Act on carbohydrates (e.g. starch -> glucose)
Protease:
- Act on proteins
Lipase:
- Act on lipids
4 main roles of the digestive system
- Ingestion - eating or drinking nutrients
- Digestion - food is broken up mechanically or chemically.
- Absorption - taking up digested molecules into the internal environment of the cells in the digestive tract.
- Egestion - the removal of wastes from the body
Chemical digestion
food is broken through the actions of enzymes and is converted into a substance suitable for absorption.
what are secretory epithelial cells & name them
- these cells are distributed through the digestive system depending on their function
- A combination of these cells makes up the tissues found within our digestive system
- Mucous cells
- G cells
- Parietal cells
- Chief cells
- Goblet cells
Mucous cells
secrete and alkaline mucus that protects the epithelium against shear stress and acid.
G cells
secrete gastrin which stimulates acid secretion