In this second part of the IBDP Biology Blog, we will look at:
- Nutrient cycles
- Absorption of food from different organisms
Energy Absorption: Autotrophs
Autotrophs: Convert Carbon Dioxide [atmosphere/dissolved in water] into Organic Compounds
Plants synthesise sugars [Glucose] then converted into organic compounds [Starch, Cellulose, Lipids, Amino Acids]
Inorganic Nutrient Compounds [Water, Carbon Dioxide, Nitrates, Phosphorous, Oxygen] obtained from Abiotic Environment [Soil, Air, Water]
Energy Source: Light
U3: Species have either heterotrophic or autoprohic method of nutrition [some species have both]
All organisms need organic molecules [Amino Acids] to carry out the functions of life [growth, motabolism and reproduction]
Energy Absorption: Heterotrophs
Heterotrophs: Rely on other organisms for energy
In IBDP Biology, we know that heterotrophs cannot make the carbon compounds needed
*Obtain them from other organisms
Types of Heterotrophs:
- Consumers
- Detrivores
- Saprotrophs
Mixotrophs: Plants and Algae use a combination of different modes of nutrition
Euglena will photosynthesise in suffcient light feeding as an autotroph but can also ingest particles of food by phagocytosis which it then digests
- Venus flytrap photocynthesises but can also catch insects and spiders to compensate for nutrient poor soil
Nutrient Cycle
Nutrients: Elements required by an organism for growth and metabolism [carbon, nitrogen, phosphorous]
The supply of nutrients is limited so ecosystems constantly recycle the nutrients between organisms. Everyone wants organic nutrients!
- Autotrophs:
Convert
nutrients from an inorganic form into organic molecules
- Heterotrophs:
Ingest other organisms to gain organic form of
nutrients
- Saprotrophs:
Breakdown organic nutrients to gain energy and in the process release nutrients back into inorganic molecules
Summary of Nutrient Cycle
- Supply of nutrients is limited therefore an ecosystem recycles
- Autotrophs convert inorganic into organic
- Heterotrophs ingest organisms to gain organic
- Saprotrophs breakdown organic and release inorganic
That's the end of part 2! Good job!
Drafted by Venetia (Biology)