module 6: organisms adapting to change Flashcards
why are cold temperatures fatal human to organisms
Cold and freezing temperatures change concentrations of solutes and cause ice crystals to form, killing cells
why are hot temperature harmful to organisms
- proteins begin to denatures
-enzymes begin to denature
-breaking their 3^o structure
what happens when you freeze a cell
· Ice forms outside of the cell (this can physically disrupt the cell, the phospholipid layer)
· Liquid water is lost from the cell to make up from the lack of liquid water outside of the cell
This tends to cause cells to die
how ca animals live in conditions where the tempreature is below 0 degrees
- Anti-freeze proteins- organism makes these protein to interreact with the ice crystals to prevent them from getting too big, helps maintain water within the cell
Have lots of solutes- serve to lower the temperature of water from freezing (about -2-3 degrees
how can taq polymerase live in hot temperatures
· Thermus aquaticus grows best at 65-70 degrees
· Enzymes optimised to function best at higher temperatures
DNA polymerase is not denatured at 95 degrees (it is stable at 94 degrees), stable and functional
what is taq polymerase used for
PCR
what are the steps for PCR
- Denature DNA - DNA is denatured to break the hydrogen bonds (94 degrees)
- Anneal the new DNA- primers are added to the DNAs (54 degrees)
- Extend- Taq polymerase synthesis a complimentary DNA molecule (72 degrees)
what is an exotherm
a type or organism that depends on the environment for their heat source (if its hot they will get hot and if it is cold they will be cold)
what is an endotherm
a type of organism that varys metabolic heat production, compensating for heat loss to the environment
what are disadvantages of being an endotherm
- Requires more food consumptions
- Inefficient energy use (ion leakage across membranes is less effective than in exotherms
-Energy spend addressing this causes an increases in heat
what are the benefits of being endotherm
- Presence in thermal niches inaccessible to exotherms (independence from environmental temp)
- They can live in different environments
- Higher muscle power and sustained activity
-Protects against infection and disease (internal environment tends to be higher then the living environment for pathogenic bacteria)
what is allen’s rule
· A rule to that is used to be able to determine the environment of an organism
· It states that animals with smaller ears live in cooler environments whereas animals with larger ears live in warmer climates
what is an example of allens rule
· Ears become smaller and face become smaller to help conserve body heat
- The big ears are a way to radiate heat and loss heat more efficiently
what is bergmanns rule
· A rule to that is used to be able to determine the environment of an organism
It states that animals with smaller ears live in cooler environments whereas animals with larger ears live in warmer climates
what is an example of allens rule
peguims become larger as you get closer to the poles
Therefore smaller animals live near the equator
is the global temperature increase bad for humans
yes, because Increasing the average temperature of the planet brings microbes to temperatures more closely aligned to ours and therefore this means pathogenic bacteria may be able to survive in our body
why is increasing CO2 bad for organisms
The increase in CO2 is happening at a rate that animals, plants, and microbes cannot keep up with, posing a big challenge.
what are 2 plant mechanisms for the intake of CO2
-C4 pathway and the CAM pathway
where are C4 plants usually located
hot and dry places
how is water efficiency in C4 plants
-close stomata during the day
- reduced water loss through transpiration
-co2 is fixed into bundle sheath cells
-minimising water loss
how is photorespiration decreased in C4 plants
- CO2 is concentrated in the bundle sheath cells which maintains a high concentration of Co2- this reduced the likelihood of rubisco favouring oxygen and losing the plant energy
- Allow them to loss less energy as ATP and NADPH are not used in energy loss like photorespiration
what is the problem with rubisco
- As temperature increases rubisco finds it hard to distinguish between Co2 and O2
- Increases photorespiration
Increases energy loss
- Increases photorespiration
what are the stages that occur in the mesophyll cells in C4 plants
- CO2 enters through the stomata into the mesophyll cell
- CO2 is converted into HCO3- (bicarbonate) which is catalysed by carbonic anhydrase (CA)
PEP carboxylase converts bicarbonate into oxaloacetate (OAA) which is then transported into the bundle sheath cells
what happens in the bundle sheath cell in C4 plants
- OAA is transported into the bundle sheath cell
- OAA is then decarboxylated releases CO2 at rubisco
- this initiated the calvin cycle
A three carbon molecule (3-PGA) is transported into the mesophyll cell
what is the CAM Process
-co2 intake
-co2 concersion
-storage
-decarboxylation
-calvin cycle
what happens in the CO2 intake stage for CAM plants, and what is the effect (time of day and result)
- Stomata opens during the night to allow CO2 to enter the cell
This means less water escapes as it is colder during the night
what happens in the CO2 conversion stage for cam plants
- CO2 is then converted into a 4 carbon molecule by the enzyme PEPC
This occurs in the mesophyll cells
what happens in the storgae stage for cam
► Storage
- CO2 is stored as a C4 acid in the vacuole in the mesophyll cell
This allows the plant to retain a high concentration of carbon until the day
what happens in the CO2 conversion stage for cam plants
- CO2 is then converted into a 4 carbon molecule by the enzyme PEPC
This occurs in the mesophyll cells
what happens in the CO2 conversion stage for cam plants
- CO2 is then converted into a 4 carbon molecule by the enzyme PEPC
This occurs in the mesophyll cells
what happens in the decarboylation stage for cam plants
- During the day the c4 molecule is decarboxylated which released CO2 and a C3 acid molecule
The C3 acid molecule is used to then be converted into starch
what is the calvin cycle
process where CO2 is used to make glucose through
-carbon fixation
-reduction
-regeneration
what is a pathogen
a disease causing microorganism
what is a disease
any condition which the normal structure or function of the body is damaged or impaired
what are the 3 stages of the immune system
- recognition
- activation
- effector stage
what happens in step 1- recognition
a pathogen is reconsided as non self by by specialised receptors present in th cell
what are the receptors called what recognize self and non self antigens
they are called pattern recognition receptors (PRR receptors)
what are the 2 locations of the PRRs
- cytoplasm
- plasma membrane
where are TLRs found (toll like receptors)
in the cell membrane
what do TLRs detect
MAMPs and DAMPs
what is a MAMP
microbial associated molecular pattern
what organism express MAMPs
virus
bacteria
paracites