Studied by 5 people
order
highly organized structures that consist of one or more cells
reproduction
reproduce their own kind- genes(DNA) are passed to the next generation
evolutionary adaptations
adaptations that are best suited for their environment evolve over generations because they ensure reproductive success
regulation
organisms maintain a beneficial controlled internal environment
cells
structural and functional units of life
biology
the scientific study of life
cell
structural and functional unit of life
the three domains of life
bacteria, archaea, and eukarya
emergent properties
new properties in each higher structural level of life that did not exist in lower levels
science
is a wat of knowing- an approach to understanding the natural world
hypothesis
a proposed explanation for an observation or a set of observations. - a prediction that can be tested - will never be proven, only supported
theory
an explanatory idea that is broad in scope, has been extensively tested with many experiments, and is supported by a large body of evidence - will never be proven, only supported
independent variable
the factor that is manipulated
dependent variable
the measure used to judge the outcome of the experiment
controlled experiment
compares an experimental group with a control group
evolution
the process of change that has transformed life of Earth from its earliest forms to the vast array of organisms living today
natural selection
a theory where populations of living organisms adapt and change to their environment
artificial selection
the selective breeding of plants and animals- humans also act as agents of evolution
DNA
the genetic material of life; responsible for heredity and for programming the activities of a cell by providing the master instructions
gene
a specific sequence of DNA that codes for a particular protein or set of proteins
signaling
information from the external and internal environment- includes the stimuli, signals, and pathways that regulate body processes and gene expression
dna
a nucleic acid - two strands coiled together into a double helix
gene expression
flow of genetic information from gene to protein
element
a substance that cannot be broken down into other substances
compound
a substance consisting of two or more different elements in a fixed ratio
atom
the smallest unit of matter that still retains the properties of an element
the three subatomic particles
neutrons-protons- and electrons
nucleus
the small dense region at the center of an atom that houses the neutrons and protons
where are electrons located
they orbit the nucleus
atomic number
the unique number of protons relating to the element
atomic mass (mass number)
the sum of the elements protons and neutrons in the nucleus
isotopes
have the same number of protons but different numbers of neutrons
radioactive isotopes
meaning the nucleus is unstable and it decays
electron shells
a level of electrons with a characteristic distance from the nucleus
chemical bonds
at atom whose outer electron shell is not full tends to interact with other atoms - they share gain or lose electrons
ionic bond
the transfer of an electron between atoms results in an attraction
ion
a atom or molecule with an electrical change
covalent bond
atoms do not transfer electrons but they share them
salt
a synonym for an ionic compound
ion
an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons
nonpolar covalent bond
electrons are shared equally because the atoms are equal in electronegativity
polar covalent bonds
electrons are pulled closer to the more electronegative atom
hydrogen bond (weak)
hydrogen atoms of a water molecule are attached to oxygen by polar covalent bonds
polar molecule
possesses both positive and negative charge
chemical reaction
breaking existing chemical bonds and forming new ones
reactants
before the chemical reaction
products
after the chemical reaction
cohesion
molecules of the same kind sticking together
adhesion
clinging of one substance to another
surface tension
a measure of how difficult it is to break the surface of a liquid
thermal energy
the energy associated with the random movement of atoms and molecules
heat
thermal energy in transfer from warmer to a cooler body of matter
temperature
intensity of heat
evaporative cooling
when a substance evaporates, the surface of the liquid that remains behind cools down
solution
a liquid consisting of uniform mixture of two or more substances
solvent
results from the polarity of its molecules
solutes
dissolves when water molecules surround them
pH scale
describes how acidic or basic a solution is
buffer
minimizes changes in pH by binding or releasing Hydrogen ions
organic compounds
contains carbon (and usually hydrogen) with covalent bonds
hydrocarbons
elements composed of only carbon and hydrogen
fossil fuels
hydrocarbon fuels formed in the geologic past from living organisms
polymers
identical or similar budling blocks strung together
macromolecule
a giant polymer
dehydration reaction
monomers linked together to form polymers
hydrolysis
when polymers are broken apart
enzymes
specialized macromolecules that speed up reactions
carbohydrates
macromolecules that contain carbon, hydrogen and oxygen
monosaccharides
sugar monomer
disaccharide
when two monosaccharides bond together
cellulose
structural - found in plant cell walls
chitin
a component of insect and crustacean and fungal cell walls
lipids
organic molecules that contain mainly carbon and hydrogen linked by nonpolar covalent bonds
hydrophobic
“water fearing’’
fats
lipids that consist of glycerol linked to three fatty acids
unsaturated fatty acids
have double bonds in the fatty acid chain
saturated fatty acids
fatty acids that are densely packed and solid at room temp
trans fat
unsaturated fats formed artificially during hydrogenation that are linked to health risks
phospholipids
components of cell membranes
proteins
polymer made up of amino acids that are folded into 3-demensional structures
enzymes
proteins that catalyze chemical reactions
denaturation
when a protein unravels, loses its specific shape, and loses its function
primary structure of a protein
the sequence of amino acids in its polypeptide chain
secondary structure
coiling or folding of the chain, stabilized by hydrogen bonds
tertiary structure
the overall three- dimensional shape of a polypeptide, resulting from interactions among R groups
quaternary structure
proteins made of more than one polypeptide
nucleotides
the monomers that make up nucleic acids
DNA
double helix
RNA
single polynucleotide chain
cell
basic unit of living matter
light microscope
can display living cells
cell theory
all living things are composed of cells and all cells come from other cells
plasma membrane
is a phospholipid bilayer with embedded proteins that regulates the flow of material into and out of the cell
cytosol
the jelly- like fluid where the cellular components are suspended
prokaryotic cells
consist of bacteria and archaea
eukaryotic cells
all forms of life that are placed in domain Eukarya
organelles
a small structure in a cell that is surrounded by a membrane and has specific function
nucleus
houses the cells DNA
endomembrane system
membranes that are inside the cell
smooth ER
synthesizes lipids and processes toxins
Note 
Flashcard (28)