Chapter 21 Flashcards
How does photosynthetically fixed Carbon return to the atmosphere?
Cellular respiration
What does primary production depend on?
Depends on mineral/inorganic nutrients to be taken up by autotrophs.
What does a typical biogeochemical cycle look like (4 steps)?
- Source: atmosphere or rocks
- Enter the soil/water and taken up by autotrophs
- Stored in organisms (living tissue)
- Part of organism falls off or entire organism dies, returning nutrients to soil and into either sediment or dead organic matter
Where is a significant part of nutrients within an ecosystem located?
Stored within organisms/living tissues.
What nutrient is NOT recycled within the ecosystem?
Carbon
What is nutrient cycling?
Recycling of nutrients within an ecosystem.
Includes the mineralization of organic nutrients by microbial decomposers.
What is retranslocation in a cycle?
Plants pull chlorophyll A into stems/branches (put it in storage), causing the leaves to turn red/orange.
This happens due to chlorophyll A being very expensive to make (a Nitrogen-heavy resource)
What is decomposition?
Breakdown of the chemical bonds formed when organic molecules/tissues are built.
What does decomposition do (3 things)
- Releases energy originally fixed by photosynthesis
- Releases CO2 and water through respiration
- Organic compounds are converted into mineral nutrients
What are the 5 decomposition mechanisms?
- leaching
- fragmentation
- changing of physical/chemical structure
- ingestion
- excretion of waste
How are decomposition organisms categorized?
Based on size and function
How do microbial decomposers function?
Secrete enzymes into tissues to break down organic compounds then absorb them.
What does bacteria (aerobic and anaerobic) decompose?
Dead animal matter
What does fungi decompose?
Plant material
How do decomposers obtain energy?
By oxidizing carbon compounds through either cellular respiration or fermentation
