AP Biology Chapters 1-3*** Flashcards
what is the core theme of biology?
evolution
what is the core theme of biology?
evolution
what are the central activities of biology?
posing questions about the living world and seeking science based answers…scientific inquiry
what are the central activities of biology?
posing questions about the living world and seeking science based answers…scientific inquiry
what is reductionism?
the approach of reducing complex systems to simpler components that are more manageable to study
what is a system?
a combo of components that function together
when a tree absorbs light from the sun to take in carbon dioxide and then releases air this is an example of what? (hint: its a theme in bio)
organisms interacting with other organisms and the physical environment
What is a bad example of human’s interaction with the environment?
the burning of fossil fuels which releases gaseous compounds into the atmosphere, including large amounts of CO2
when trees absorb light to make life possible this is an example of what? (hint: one of the themes of bio)
Life requiring energy transfer and transformation…the use of energy to carry out life’s activities
what is sugar (or energy) used for in an animals cells?
-used as fuel to convert chemical energy to kinetic energy such as movements of animals
Form fits function…what theme in bio does this show?
structure and function are correlated at all levels of biological organization..knowing the function of something provides insight into its construction
the activities of organisms of organisms are all based on the activities of cell…this shows which bio theme?
The cell is an organism’s Basic Unit of structure and function
what are some characteristics that all cells share
- every cell is enclosed by a membrane that regulates the passage of materials between the cell and its surroundings
- every cell uses DNA as its genetic info
what is the largest organelle in the eukaryotic cell?
the other organelles are located where?
which are simpler..eukaryotic or prokaryotic?
- nucleus
- cytoplasm
- prokaryotic
When cells utilize DNA to grow and repair other cells it shows which theme in Bio?
The continuity of life is based on heritable info in the form of DNA
explain what is in a chromosome?
one very long DNA molecule with hundreds or thousands of genes arranged along its length..genes encode info necessary to build other molecules in the cell, MOST NOTABLY PROTEINS
What do proteins do?
carry out cellular work
what does DNA provide for proteins?
it provides the blueprint for making proteins and proteins carry out cell’s work
what are the 3 domains?
bacteria, archaea, and eukarya
which of the 3 domains have prokaryotic cells?
archaea and bacteria
What did Charles Darwin come up with and explain this idea.
Natural selection- individuals with inherited traits are best suited to the local environment are more likely to survive and reproduce than less suited individuals
organisms are composed of….
matter is made up of ….
- matter
2. elements
how many elements?
92
of the complete list of elements what percent of them are essential elements?
20-25%
do all organisms need the same type and amount of essential organisms?
no it varies from organisms
what four elements make up living matter?
oxygen, carbon, hydrogen, and nitrogen
what are the subatomic particles?
electrons, neutrons, protons
the neutron and proton each have a mass of….
1 Dalton
for isotopes do they have different number of protons or neutrons?
neutrons! PROTONS STAY THE SAME!
what is a stable isotope?
their nuclei do not have a tendency to lose particles
what is radioactive isotopes useful for?
bio research, diagnostic tools for medicine, PET scanners, etc
what is half life?
time for 50% of an isotope to decay
what are radioactive tracers?
diagnostic tools for medicine..isotopes of P, N, and H used to determine DNA structure
true or false: atoms are mostly empty space?
true
true or false: matter has a natural tendency to move to the lowest possible state of potential energy
true
true or false: the less distance an electron is from the nucleus, the greater the potential energy
FALSE…the more distance an electron is from the nucleus, the greater the potential energy
which electron shell has the lowest potential energy?
the first electron shell
when an electron absorbs energy…
it moves to a shell farther out from the nucleus
what do periods (rows.. left to right) tell you about an element on the periodic table?
number of electron shells in their atoms
the columns show…
number of electrons in their valence shell
how do you know what is the bonding capacity of an atom?
bonding capacity corresponding to the number of covalent bonds the atom can form
what is the difference between pure elements and compounds?
pure elements is the grouping of the same element like H2 and compound is the grouping of different atoms like H2O
true or false: oxygen is the most electronegative of all the elements
true
if an element has say 11 protons and 10 electrons (because one was taken away in a ionic bond) what does that say about the element?
the element has a positive charge of 1+
do cations and anions attract to eachother?
yes because they have opposite charges…positive and negative
explain the ionic bonding
the transfer of an electron isn’t really the bond rather the transfer of the electron allows for a bond between the two ions..anions and cations
fill in..”unlike a covalent compound, which consists of ___ having a definite size and number of atoms, an ionic compound does not consist of ___
molecules
the formula for ionic bonding only shows what?
the ratio of elements
which are some of the most strongest bonds?
covalent bonds
ions are fragile in what?
when in water
how are many large biological molecules held in their functional forms
they are held by weak bonds
how can weak bonds be an advantage?
two molecules can come together, respond to one another in some way, and then separate
why do van der Waals interactions occur?
because there are ever changing regions of positive and negative charge that enable all atoms and molecules to stick to one another. together they are very strong. This is what allows a lizard to walk up a wall.
-constant movement of electrons allow parts of atoms to be briefly attracted
a molecule with two atoms is always in what shape?
linear
what determines the shapes of molecules when there is more than two atoms
by the positions of the atoms’ orbitals. When an atom forms covalent bonds, the orbitals in its valence shell undergo rearrangement
What does hydrogen usually bond to?
Oxygen or nitrogen
Hydrogen bonds-..
bond formed by the charge attraction when a hydrogen atom covalently bonded to one electronegative atom is attracted to another electronegative atom
- attraction between oppositely charged portions of polar molecules
- can occur between a hydrogen that has slight positive charge when covalently bonded to an atom of higher electronegativity
endorphins
chemicals that make you feel good (natural)
morphine and heroine because of their shape can do what?
have shape to fit endorphin receptors..or same shape as endorphins. so make you feel good
Chemical equilibrium?
forward reaction=rate of reverse reaction
how are chemical reactions reversible?
by having the products of the forward reaction becoming the reactants for the reverse reaction
what can affect the rate of reaction?
the concentration of reactants..the greater amount of concentration the more frequently they collide with one another and have an opportunity to react and form products
when water is in liquid form what are the hydrogen bonds like?
the bonds are weak and are constantly breaking and forming again and again.
what are the 4 emergent properties of water?
- Cohesion of water molecules
- Moderation of temperature (specific heat)
- Floating on ice
- Being the Solvent of life
are hydrogen bonds more or less structured than most other liquids?
more structured
how does water moderate temperature?
water absorbs heat from air that is warmer and releasing the stored heat to air that is cooler
anything that moves has…
kinetic energy
the difference between heat and temperature?
heat is the measurement of kinetic energy and temperature is the measurement heat intensity
whenever two objects are put together what happens with heat?
heat passes from the warmer to the cooler object
hydrogen bonds must ___ to break, and they release ___ when they are formed
heat
how is temperature of water increased?
heat is absorbed and used to break Hyrdrogen bonds before water can move faster
what is a unit of heat?
one calories (1 kilocalorie = 1000 calories) or 1 joule (which equals .239 calories)
what is the relevance of water’s high specific heat to life on earth?
a large body of water can absorb and store a huge amount of heat from the sun in the daytime and during summer while warming up only a few degrees
-also tends to stabilize ocean temp
can some evaporation occur at a low temperature?
yes
the high amount of energy required to vaporize water has what effects?
- helps moderate earths climate..solar heat absorbed can be consumed during the evaporation of surface water
- then can release heat as it condenses and forms rain.
- accounts for the severity of steam burns
what does evaporative cooling help in?
- contributes to the stability of temp in lakes and ponds
2. provides a mechanism that prevents terrestrial organisms form overheating on a hot day
how does water act like when being frozen?
in the beginning acts like other liquids by expanding as it warms and contracting as it cools.. BUT THEN as temp falls from 4 degrees Celsius to 0 degrees Celsius then molecules are locked into crystalline lattice..hydrogen bonds keep themselves at “arms length”
why is water the most popular solvent?
because of its polarity it can pull apart molecules and substances
does a compound need to be ionic to dissolve in water?
no but it has to be polar
what can occasionally happen with a hydrogen atom participating in a hydrogen bond between two water molecules? and what does this cause?
a hydrogen atom can shift from one molecule to another. This causes for the hydrogen atom to leave behind an electron thus only “transferring” a HYDROGEN ION (a single proton)…the water molecule that lost the proton is now a HYDROXIDE ION (charge of 1-) …the proton binds to the other water molecule making that molecule a HYDRONIUM ION
what would cause an aqueous solution to have an imbalance in H+ and OH- concentrations?
when acids dissolve in water, they donate additional H+ to the solution
a substance that reduces hydrogen ions is..
a base…reduce them by simply accepting hydrogen ions or dissociating to form hyrdoxide ions
is ammonia a strong or weak base?
weak
what is the equation for the pH scale?
pH= -log [H+]
in any aqueous solution at 25 degrees Celsius, the product of the H+ and OH- is constant at ….
10^-14
at what number is a solution neutral?
acidic?
basic?
- 7
- less than 7
- greater than 7
an acid not only adds ___ ions to a solution but also removes ___ because of the tendency for H+ to combine with OH-, forming water
- hydrogen
- hyrdroxide ions
what is the internal pH of most living cells?
7
how does a buffer work?
it either accepts hydrogen ions from the solution when they are in excess and donating hydrogen ions to the solution when they have been depleted
what is an example of a buffer
-carbonic acid
what happens when the gaseous compounds that were put into the environment by humans interact with water?
the water becomes more acidic, altering delicate balance.
CO2 dissolves in seawater and forms carbonic acid which lowers pH…known as OCEAN ACIDIFICTATION
Acid precipitation
rain, snow, or fog with a pH lower than 5.2
