bio essays Flashcards
importance of membranes
action potentials
ao1
- Stimulus triggers sodium ion channels to open
- Na+ move in
- if enough move in and threshold value is reached, depolarisation occurs and an action potential is generated
- response to stimulus
importance of membranes
action potentials
ao2
- In order to respond to stimulus
- avoid pain
- without membrane, Na+ channels couldn’t open to allow for Na+ in and depolarisation wouldn’t occur - no action potential
importance of membranes
electron transport chain
ao1
- Chemiosmosis / Oxidative Phosphorylation
- Electron movement generates energy for proton transfer
- Protons move into inter membrane space, generating a concentration gradient
- Move back into mitochondrial matrix/thylakoid by co-transport by ATP synthase - generates ATP
importance of membranes
electron transport chain
ao2
Generates ATP for other bodily functions - metabolism, transport, expression
- without membranes proton diffusion couldn’t occur and atp would not be generated (as much?) and more photosynthesis or respiration
importance of membranes
exchange (fish)
ao1
countercurrent flow
blood and water flow in opposite directions
maintains concentration gradient across entire gill lamella
constant oxygen diffusion from water into blood stream
importance of membranes
exchange (fish)
ao2
constant oxygen diffusion
allows for fish to constantly respire and not lose oxygen
importance of membranes
tissue fluid
ao1
small molecules out including water
small molecules form tissue fluid
creates lower hydrostatic pressure in capillaries
which allows water to diffuse back in by osmosis
importance of membranes
tissue fluid
ao2
allows water to be in blood stream again to facilitate bloods movement
also removes non-essential molecules in blood
and forms tissue fluid
importance of microorganisms/microbes
humoral response
ao1
antigen presenting cells activate t cells
t cells activate b cells
b cells can be either plasma or memory cells
plasma cells make more b cells and memory cells remember pathogens
importance of microorganisms/microbes
humoral response
ao2
long term immunity
remember pathogens for rapid response upon reinfection
importance of microorganisms/microbes
nitrogen cycle
ao1
nitrifying and denitrifying bacteria
importance of microorganisms/microbes
nitrogen cycle
ao2
enables nitrogen to be absorbed into plants
(re)formation of nitrogen gas
amino acid amine groups - essential molecule
importance of microorganisms/microbes
in vivo cloning
ao1
restriction endonucleases come from bacteria
cut dna fragments and insert them into plasmid vectors that come from bacteria
importance of microorganisms/microbes
in vivo cloning
ao2
enables copying of dna
many copies can be formed
importance of microorganisms/microbes
succession
ao1
pioneer species typically microbes eg algae
importance of microorganisms/microbes
succession
ao2
colonise and reduce hostility of area to make it habitable to other species
allow for succession and biodiversity
importance of different relationships + interactions between organisms
mycorrhizae
ao1
fungus that associates with plant roots to increase their surface area
importance of different relationships + interactions between organisms
mycorrhizae
ao2
allows for more water and nitrogen absorption - chlorophyll for leaves
importance of different relationships + interactions between organisms
courtship behaviour
ao1
dances, chemicals, colours, appearances
importance of different relationships + interactions between organisms
courtship behaviour
ao2
increase reproduction
increase population size
increased advantageous alleles
increase survival and adaptation
importance of different relationships + interactions between organisms
humoral response
ao1
bacteria and b cells interaction - antigen presenting cells and pathogens
triggers t cells to activate b cells (plasma or memory)
importance of different relationships + interactions between organisms
humoral response
ao2
long term active immunity
memory cells remember pathogens/antigens for rapid response upon reinfection
importance of different relationships + interactions between organisms
natural selection
ao1
competition causes for advantageous alleles that allow for survival and better adaptation to be passed on
cause for increase in this allele frequency
importance of different relationships + interactions between organisms
natural selection
ao2
make entire population more adapted to competition and environment and selection pressures
increased survival
