Lecture 1 Flashcards
How can temperature disrupt macromolecules?
Protein folding & assembly
Nucleic acid secondary structure (“break DNA”)
Lipid physical state (“fluidity”)
Protein-nucleic acid interactions
What non-covalent (“weak”) chemical bonds exist in biological structures?
hydrogen bonds
ionic interactions
van der Waals forces
hydrophobic effects
Describe marginal stability in context of biological structures.
The tertiary structure and associated movement allowed by weak bonds, which allows the movement needed to perform its job.
Describe the trade-off associated with weak chemical bonds in biological structures.
Weaker forces allow for flexibility, but make it susceptible to environmental stressors like temperature.
Describe the relationship between temperature and physiological reactions in the context of speed.
As temperatures go up, reaction speed increases.
As temperatures go down, reaction speed decreases.
What do environmental stresses do to physiological traits?
Stressors shift traits out of optimal ranges of function/structure; into sub-optimal ranges (too slow/ too fast)
Describe Q10 effects.
Describes temperature sensitivity of biochemical reactions. Change temp. in 10°C intervals and find rates often change by 2-3 fold.
Give an example of temperature effects on solute solubilities.
Cold liquids hold more gas than warm liquids. Increased temps reduces O2 solubility, thus, decreased temps increases O2 solubility.
Describe how temperature affects acid-base balance.
Increased temps promotes dissociation of weak acids, increasing H+, lowering pH (making acidic).
What is the upper temperature limit eukaryotic life can approach?
55-60°C
What is an ectotherm?
An organism whose body temp. is defined by the environment.
What is a poikilotherm?
An organism whose body temp. changes according to environment, but may not be identical to environment such as in the case of behavioral changes.
What is an endotherm?
An organism who generates their own body heat.
What is the difference between a heterotherm and a homeotherm?
A heterotherm’s body temp. is not identical throughout/ different temps. exist in different regions in body; a homeotherm’s body temp. is identical through its entire body.
What is the difference between a stenotherm and a eurytherm?
Stenotherms tolerate narrow temperature range; eurytherms tolerate broad temperature range.
What is the difference between a thermophile and a psychrophile?
Thermophiles are dependent on hot temperatures; psychrophiles are dependent on cold temperatures.
What is a eurytolerant organism?
An organism with a wide ability to cope with diverse abiotic changes.
What is a congeneric species? What are they commonly used to study?
2+ species in the same genus who are closely related as can be without being the same; good for studying thermal relationships.
Describe the relationship between heat tolerance and vertical/ latitudinal distributions.
Heat tolerance is higher in lower latitudes/ higher vertical positions. Organisms in higher latitudes/ lower vertical positions (intertidal) have less heat tolerance.
Describe the relationship between phenotypic plasticity and tolerance.
Some organisms can acclimate to tolerate abnormal temperatures; adjust “zone of tolerance.”
List two examples of vertical position and thermal tolerance relationships.
Species from the Tegula genus and Littorina genus who had higher vertical position lasted longer/ survived at higher temps than those in lower positions.
What is the Arrhenius “break” temperatures (ABTs)
The point where mitochondria stop generating ATP.
How to Arrhenius break temperatures (ABTs) change when acclimated to heat? What is responsible for the change?
If you acclimate the temperature higher = ABT increases due to decreased membrane fluidity.
Do “hot” species have ABTs nearer to or further from body temperature than “cold” species?
“Hot” species ABTs are NEARER TO body temperature than “cold” species.
