digestion Flashcards
what are the 4 stages of digestion
- ingestion
- digestion
- absorption
- egestion
what is ingestion
Is the process in which organisms take food into their digestive systems
what are the different ways organisms feed
- suspension feeders
- substate feeders
- fluid feeders
- bulk transport
what are suspension feeders
sift small particles out of passing water
what are substate feeders
live in or on their food source
what are fluid feeders
suck fluids from a host
what are bulk feeders
ingest large pieces of food
what are 2 examples of organisms which are classed as suspension feeders
- clams
- sponges
what are 2 examples of organisms which are classed as substrate feeders
- maggots
- caterpillars
what is an example of an organism which is classed as a fluid feeder
- mosquito
what is an example of an organism which is classed as a bulk feeder
- most animals
what is digestion
The breakdown of complex organic molecules into smaller components by mechanical and chemical digestion
what are the two types of digestion
- mechanical digestion
- chemical digestion
what is mechanical digestion
chewing and muscular movements to physically reduce the size of the substances
what is chemical digestion
enzymes break chemical bonds to reduce the substances into their simple components
what are the first stages of mechanical digestion
chewing with the teeth and the tongue rolling food into a bolus.
what are three different enzymes which take part in chemical digestion
pepsin + protease
lipase
amylase
what does pepsin + protease break down and what are their products
break down proteins into amino acids
what does lipase break down and what are their products
break down lipids into glycerol and fatty acids
what does amylase break down and what are their products
break down carbohydrates into glucose
what is absorption
The taking up of digested molecules into the internal environment. Substances enter the cells through diffusion and active transport.
what is special about the small intestine which assists them during the absorption phase
the small intestine maintains a high SA with small finger-like projections called villi. These villi have even smaller structures called microvilli
what is egestion
Is the release of waste material. For organisms with a complete alimentary canal, this generally happens through the anus.
if organisms do not have an alimentary canal how do they egest waste
gastrovascular cavity
what is a gastrovascular cavity
A gastrovascular cavity is a single opening in organisms. This opening allows food to enter and waste to pass out.
what is an example of an organism that has a gastrovascular cavity
jellyfish
What is the alimentary canal
The alimentary canal is a more specialised digestive system that spans from the mouth to the anus. Food passes through all the organs.
