living things are made up of basic units called _________
cells
living things are based on a universal genetic _________
code
living things grow, develop, and __________
reproduce
living things respond to their ______ as they mature
environment
living things maintain a stable internal _________
environment
living things obtain and use materials and ________
energy
genetic molecule common to all living things is ________
DNA
internal process of ________ enables living things to survive changing conditions
homeostasis
living things are capable of responding to different types of _____
stimuli
living things have a long history of ________ change
evolutionary
the continuation of life depends on both ________ and _________
asexual reproduction
sexual reproduction
combination of chemical reactions that make up an organism's _________ help to organize raw materials into living matter
metabolism
cellular basis of life
living things are made up of cells
information and heredity
DNA, universal genetic code
organisms use matter and energy to live
life requires matter the provides raw materials, nutrients, and energy
homeostasis
living things maintain a relatively stable internal environment
evolution
change in groups of organisms over time
all living things have structures that have specific functions to help them live
each major group of organisms has evolved structures that make particular functions possible
diversity and unity
all living things are fundamentally similar at the molecular level
interdependence
all forms of life on earth are connected into a biosphere--a living planet
science as a way of knowing
scientific method (science is a process based on theory not facts)
"That boy shot up five inches in only one year."
growth
"Our cat had a litter of kittens yesterday."
reproduction
"My dog has become much less clumsy now that he is a year old."
development
"Eat a good breakfast and you will be able to run longer."
metabolism
"When that car pulled in the driveway, my cat ran to hide under the porch."
responding to stimuli
"That owl's night vision allows it to see the movement of mice on even the darkest night."
natural selection
"Single-celled organisms live in the pond behind school."
bacteria
your body normally maintains a temperature of 98.6 degrees F
homeostasis
giraffes use their long neck to eat from the high branches of a tree
natural selection
_______ is another name for "living thing"
organism
chemical element is a pure substance that consists entirely of one type of ______
atom
atoms of the same element that differ in the number of neutrons they contain are called ______
isotopes
atom is made up of protons, neutrons, and _______
electrons
________ and _______ are located in the nucleus
protons and neutrons
What is a chemical compound?
two or more chemically combined elements
What do the formulas for table salt, NaCl, and water, H2O, indicate about these compounds?
what elements and proportions are used to create the compounds (NaCl=1:1, H2O= 2:1)
What is the difference between an ionic compound and a covalent compound?
Ionic transfer electrons
Covalent share electrons
How are chemical bonds important in a metabolism?
release/break of bonds provides energy
three particles that make up atoms are
protons, neutrons, and electrons
what are found in the space surrounding the nucleus of an atom?
electrons
isotopes are atoms of the same element with the same number of protons and a different number of
neutrons
what is formed by the chemical joining of two or more elements in definite amounts?
compound
what type of ion forms when an atom loses electrons?
positive (cation)
all isotopes of an element have the same number of ______ and ______
protons and electrons
chemical bond formed by the transfer of electrons is a(an)_______
ionic bond
describe how a sodium atom forms a bond with a chlorine atom
sodium and chloride form an ionic bond because sodium is a metal with a charge of 1+ and chlorine is a nonmetal with a charge of 1-. The cation, sodium, gives an electron to the anion, chlorine.
Why are atoms considered neutral?
atoms are considered neutral because they have equal numbers of protons and electrons
explain a covalent bond
bond between metals that share electrons
what atom in water have a more negative charge?
oxygen
what atom in water have a more positive charge?
hydrogen
what kind of bond holds water molecules together?
hydrogen bonding
what keeps water flowing in a stream rather than dispersing into a bunch of separate water molecules?
cohesion
Water is polar, so ______ substances dissolve in it, and ______ do not.
polar do, non-polar do not
hydrophobic
fears water, non-polar, non-dissolving (in water)
hydrophilic
water loving, polar, dissolving (in water)
why does it make sense that our cell membranes are made of lipids?
to hold water in
what property causes a meniscus in a graduated cylinder filled with water?
adhesion
DNA
complex molecules that store info needed to live
stimuli
signal in environment to which organism reponds
sexual reproduction
cells from 2 parents unite to produce NEW organism
asexual reproduction
single cell produces IDENTICAL organism to itself
homeostasis
condition where organism maintains in internal environment despite changes in exterior environment
simple molecules
ordered together in larger macromolecules
cells
basic unit of life
made up of one or more cell, makes it a
living thing
viruses
"borderline organisms"
cannot reproduce unless infect another organism
not infecting cell=
not living cell
bacteria are all
unicellular
not all unicellular things are
bacteria
humans are ____-cellular, meaning they are made of many cells
multi(cellular)
earth is ______ years old
4.6 billion
life on earth is ______ years old
3.5 billion
hierarchy of life (bottom to top)
atoms
molecules
macromolecules
organelle
cells
tissues
organs
organ systems
organism
population
community
ecosystem
biosphere
hierarchy of life is a way of _________
interdependence
chemical reactions occur to keep living things _____
alive
basic unit of matter
atom
Democritus
Greek philosopher who discoverd the atom
"atomos"
means unable to cut
element
pure substance containning only one type of atom
atomic number
number of protons
unique to each element
atomic mass
average of isotopes mass number
number of protons plus the number of electrons
physical and chemical properties of a compound _____ from original elements' its composed of
differ
valence electrons
electrons available fin outermost shell for chemical bonds
determine chemical behavior of atom
single bond
2 e- shared
double bond
4 e- shared
triple bond
6e- shared
molecule
smallest unit of compounds
van der waals forces
atoms of different elements have different ability of attraction
atoms in covalent bond share electrons, but not equally
creates tiny (partial) positive or negative charge
not as strong as covalent bonds or ionic bonds
matter
takes up space
has mass
deficiencies
deficiency of an essential element results in disease
trace elements
required by organism in minute quantities
ex: minerals such as Fe and Zn
properties of matter
depend on structure of its atoms
absorbed energy
gaining energy
moves to higher shells
losing energy
moves to lower shells
potential energy
energy matter possesses because of location or source
kinetic energy
energy of motion
energy levels are represented by
electron shells
chemical behavior of an atom is defined by its
electron configuration and distribution
orbitals
3D space where electron found 90% of time
consists of specific number of orbitals
each can hold up to 2e_
electronegativity
the attraction of a particular kind of atom for electrons in a covalent bond
more electronegativity = more strongly it pulls shared electrons towards itself
non-polar covalent bond
atoms have similar electronegativities
share the electrons equally
polar covalent bond
atoms have different electronegativites
share electrons unequally
anion
negatively charge ion
cation
positively charged ion
ionic compunds
salts which can form crystals
weak chemical bonds
reinforce shapes of large molecules
help molecules adhere to eacother
s and p orbitals may _______, creating specific molecular shapes
hybridize
subatomic particles
protons
neutrons
electrons
diatomic
two of the same elements have to be linked together (I,Br,Cl,F,O,N,H)
7 diatomic elements
types of formulas
molecular-same empirical formula but with exact amounts (most exact)
empirical- tells kinds of elements and ratios (simple ratio)
structural-shape
ionic bond is a _______ and _______
metal and non-metal
metals
cation on left of periodic table
charge depends on group # (column)
give up electrons
nonmetals
anions on right of periodic table
charge depends on 8-group # (one's place)
gain electron
catabolism
chemical reactions that break things down (release energy)
anabolism
chemical reactions that build things up (capture energy)
water's electrons found near _______
oxygen nucleus
cohesion produces
surface tension
capillary action
draws water up plant's roots
water's heat capacity
high b/c large amount of heat needed to make molecules move faster due to hydrogen bonds
water is not always pure
ex: found in mixture
mixture
material composed of 2+ elements or compounds that are physically mixed together but not chemically combined
2 types of mixtures
solutions and suspensions
solution
all components evenly distributed
solute and solvent
solute
dissolved
solvent
dissolver
water is the greatest______ on earth
solvent
suspension
mixture of water and nondissolved solutes
blood is an example of
solution and suspension
water molecules sometimes split to form ___
ions
pH scale
measurement system to indicate concentration of H+ ions in a solution
basic
below 7 pH
acidic
above 7 pH
buffers
weak acids or bases that produce quick changes with strong acids or bases
properties due to hydrogen bonds
cohesion
resists change in temp
high heat vaporization
expands when freezes
versatile solvent
surface tension
measure of force necessary to stretch or break the surface of a liquid
relates to cohesion
water moderates temp. on earth
stabilizes air temp. by absorbing warmer air and releasing heat to cooler air
Celsius scale at sea level of water temps.
100C-boils
37C-human body temp
23C-room temp
0C-freezes
specific heat
amount of heat that must be absorbed/lost for one gram of substance to change its temp by one degree celcius
water on earth produces "heat sink"
gives coastal areas mild climate
stables marine environment
prevents heat fluctuations outside range suitable for life
evaporative cooling of water
moderates earth's climate
stabilizes temp in aquatic ecosystems
prevents organisms from overheating
density of water
most dense 4C
contracts at 4C
expands from 4-0C
prevents water from freezing bottom up
ice forms on surface first
freezing of water releases heat to water below to create insulation
crystal lattice of water at 0C
each molecule bonded with max of 4 partners
ice melts, bonds break
2 important quantitative properties of aqueous solutions
concentration
pH
molecular weight
sum of weight of atoms in molecule in daltons
mole
amount of substance that has amass in grams numerically equivalent to its molecular weight in daltons
molarity
concentration of a material in solution
dissociation of water molecules
occasional switch of one hydrogen atom leaving H2O to another H2O
results in hydronium H3O and OH
strong acids and bases
completley dissociate in water
weak acids and bases
only partially/reversibly dissociate
most biologic fluids are in the pH range of _____
6-8
pH scale represents tenfold differences
logarithmic scale
small change in pH is a dramatic change in H+ and OH- concentrations
intra
means inside of molecules
inter
means between molecules
dotted line represents _______ bond
hydrogen
solid line represents _________ bond
covalent
Why do trees have capillary action with small tubes rather than large tubes?
small tubes have less of a meniscus so water can adhere all the way up to the top of the tree
