nutrients Flashcards
what is nutrition
obtaining nutrients to provide energy to maintain life functions and matter to create and maintain structure
what is energy
the capability of a physical system to do work
what are autotrophs
use simple organic molecules such as water and CO2 to manufacture energy containing complex or organic compounds
what are heterotrophs
depends on autotrophs for food supple. they consume complex organic food material which must be broken down before use
what are the two different types of autotroph
photosynthetic
chemosynthetic
how does a photosynthetic autotroph make food
green plants build up complex molecules such as sugar from CO2 and water. light is the source of energy for the production of food
how does a chemosynthetic autotroph make food
use energy derived from special methods of respiration to synthesis organic food. chemical activity is the source of energy for the production of organic compounds
what are the four different types of hetertrophs
saprophytes, holzoic, parasites and mutualism
how do saprophytes feed
secrete enzymes onto the food material outside the body and then absorb the soluble product across the cell membrane by diffusion. this is known as extracellular digestion
secrete enzymes such as protease, amylase from the very tip of the structure called the hypha
absorbed by the diffusion across the cell membrane
when products are absorbed they can either be used immediately or transported all over the mycelium
important in globular systems as they decompose dead plant matter such as leaf litter and recycle nutrients such as nitrogen
how do holzoics feed
take food in and break it down by the process of digestions
most have a specialised digestive system
digestive material is then absorbed into the body tissue
herbivores = solely plant material
carnivores = feed on other animals
detrivores = animals that feed on dead or decaying material
how do parasites feed
feed on or in living organisms. the host always suffers harm to some degree
highly specialised and show considerable adaptation to their particular way of life
how do mutualists feed
close association between members of two different species
but both derive some benefit from the relationship
e.g. the digestion of cellulose by micro-organisms in the gut of a herbivore
