Biodiversity Week 2 Part 3 Flashcards
how does energy enter ecosystems
via primary producers
autotrophs
organisms that can synthesize their own food from inorganic sources
do primary producers create energy
no, they transform energy in sunlight of inorganic compounds into chemical energy stored in organic molecules
gross primary productivity
total amount of chemical energy produced in a given area and time period
how do primary producers use GPP chemical energy
- cellular respiration
- growth and reproduction
net primary productivity
energy that is invested by primary producers in building new tissue or offspring
what links these concepts together (NPP, GPP)
- energy is lost from primary producers during processes as molecular waste and heat without being used
NPP=GPP-R
what does NPP represent
total amount of chemical energy that is stored in organic material
- biomass
- amount of energy available via primary producers to other organisms
about how much of GPP go to NPP
45%
what is the other 55% used for
cellular respiration
lost from organism as heat
what is the flow of energy
- Comsumers eat living organisms
- primary consumers eat primary producers
- secondary consumers eat primary consumers
- tertiary consumers eat secondary consumers
when does energy flow
when one organism eats another
does energy continuously cycle
no, it is lost as heat
- nutrients continues to cycle
what is a trophic level
a feeding level in an ecosystem
food chain
focuses on one possible pathway of energy flow among trophic levels in an ecosystem
grazing food chain
ecological network of primary producers, herbivores, and the predators that consume them
decomposer food chain
ecological network of detritus, decomposers that eat detritus, and predators of the decomposers
primary decomposer
decomposer that consumes detritus from plants
what would a complete food web include
all the organisms interacting in the ecosystem along with estimates of amount of energy transferred at each link
what pattern do all ecosystems share
total biomass produced each year declines from lower trophic levels up to higher levels
productivity
rate
efficiency
dimensionless ratio
what is a rough estimate of the efficiency of biomass transfer from one trophic level to the next
10%
where does the biomass go that is not transferred
released as carbon dioxide and waste
where does chemical energy go that is not transferred
dissipated as heat
what type of mammals are more efficient at producing biomass
large mammals
biomagnification
increase in concertation of heavier metals in consumer at higher levels in a food chain
when is NPP higher
on land because more light is available to drive photosynthesis
which terrestrial ecosystems are most productive
located in wet tropics
which marine ecosystems are most productive
highest along coastlines because the shallow water along coats receives more nutrients
- algal beds
- coral reefs
- wetlands
- estuaries
about how much NPP are humans currently preventing
24%
what are the nutrient acquisition methods
- phagocytosis
- pinocytosis
- absorption
absorption
cells take up small organic molecules directly from environment
selective uptake
- proteins in plasma membranes
- specific proteins in plasma membranes of cells responsible for reorganizing and transporting particular nutrients
active transport energy requirement
- absorption requires ATP to move nutrients against concentration gradients
metabolic diversity of bacteria and archaea
wide range of metabolic pathways
- able to absorb and utilize organic and inorganic compounds
what do cotransporters use to bring glucose to the cell
use electrochemical gradient of sodium ions
what are the key points to absorption process
- highly selective
- energy dependent
- metabolic diversity
phagocytosis
cell eating
- used for large particles or cells
what is the process of phagocytosis
cell’s membrane surrounds a smaller cell or food particle
what is formed from the process of phagocytosis surrounding a cell
phagosome
what is fused together in phagocytosis
phagosome is delivered to lysosome and their membranes fuse
how does digestion occur in phagocytosis
contents of phagosome are digested by enzymes in lysosome
pinocytosis
- cell drinking
- used for fluids and dissolved substances
how does the process of pinocytosis engulf fluid
- cell’s plasma membrane pinches to form small vesicles
- vesicles contain extracellular fluid and dissolved substances
how are the vesicles of pinocytosis form
invagination of plasma membrane
internalization step of pinocytosis
vesicles move into cell and contents can then be processed
