Topic 2 Flashcards
three domains of life
bacteria, archea, eukarya
linnaean taxonomy
the huge spectrum of all the merged species
- organisms are written with two names
the two major types of organisms
prokaryotic and eukaryotic
prokaryotic and eukaryotic shared features
plasma membrane, ribosomes, cytoplasm, DNA
prokayotics include which domains
bacteria and archaea
- can be found in extreme locations
- most abundant organisms on earth
prokaryotic cell 5
- cell is simple
- small
- does not contain a nucleus or other membrane bound organelles
- lack compartmentalization
- dna is circular
eukaryotic cells 4
- larger
- membrane bound organelles
- largest organelle is nucleus
- compartmentalization of cell
four major eukaryotic kingdoms
plants (photosynthesis)
fungi (absorb nutrients)
animals (ingest their food)
protists (mostly sing celled)
domain bacteria
- include most prokaryotic species
- pathogenic to humans (harmful)
- beneficial to humans (cheese)
- research
domain archaea
- prokaryotic cells
- live in extreme enviro (extremophiles)
- extreme halophiles (saline)
- extreme thermophiles (temp)
domains shared characteristics
- dna backbone to life
- bacteria and archaea both prokaryotes
matter
anything that takes up space and has mass
- organic or inorganic
- consists of chemical elements in pure form and in combinations (compounds)
chemical equilibrium
reached when forward and reverse reactions occur at the same rate
atom
smallest unit of matter that still retains properties of an element
isotopes
differ in number of neutrons
radioactive isotopes
decay spontaneously, giving off particles and energy
- PET scan
covalent bond
share a pair of electrons
- the electron count as part of each atoms valance shell
molecule
2 + atoms held together by covalent bond
compound
covalent bond between different atoms
polar covalent bond
atoms do not share electrons equally
hydrogen bonds
- weak chem interaction
- H atom covalently bonded to one electronegative atom and it is also attracted to another electroneg atom
- usually N or O
water
only substance to exsist in all states naturally
is water polar
yes
- electrons spend more time near the oxygen than the hydrogen
- polarity allows hydrogen bonds to form with other water molecules
4 emergent properties of water enable the suitability for life
- cohesive behaviour
- ability to moderate temperature
- expansion upon freezing
- versatality as a solvent
cohesion
hydrogen bonds hold water molecules together.
- helps transport water agains gravty in plants
ahesion
attraction between different substances
surface tension
measure how difficult it is to break the surface of a liquid
- water has high surface tension due to hydrogen bonding
waters ability to moderate temp
absorbs heat from warmer air and releases stored heat to cooler air
- water can act as a heat bank
thermal energy
the total kinetic energy associated with random motion of atoms or molecules
temperature
average kinetic energy of molecules in a body of matter
waters specific heat
high specific heat. that is why it resists chnage in temperature
specific heat of something
- amount of heat needed for 1g of the thing to raise by 1 degree
why does water have high specific heat
- hydrogen bonding
- heat is absorbed to break bonds
- heat is released when bonds form
what does having a high specific heat capacity do
acts as a buffer to minimize temperature fluctuations to permit life
heat of vapourization
the heat a liquid must absorb for 1g to be converted to gas
- breaks hydrogen bonds
evaporative cooling
as liquid evapourates its remaining surface cools
- when this happens to water it helps to stabalize temperatures in organisms and bodies of water (sweating)
why does ice float in water
becuase hydrogen bonds in ice are more ordered making ice less dense than water
what temp does water reach greatest density
4 degrees
solvent vs solute
solvent- dissolving agent of a solution
solute- substance that is dissolved
why is water a versatile solvent
polarity
amphipathic
substance is one that has both hydrophilic and hydrophobic properties
water is in a state of what
dynamic equilibrium
- water molecules dissociate at the same rate at which they form
buffers
minimize chnages in concentrations of H+ and OH- in a solution
ocean acidification
- co2 main product of fossil fuel combustion
- 25% absorbed in ocean
- Co2 dissolved in seawater forms carbonic acid
- H+ ions combine with carbonate to produce bicarbonate
carbonate is used for what
calcification- building coral reefs
