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225 terms

BIO 112

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atom
particle made up of protons, neutrons, and electrons
compound
the chemical combination of 2 or more elements in specific amounts
metabolism
all of the chemical reactions that build or break down materials within an organism
axon
long fiber that carries electrical impulses away from the nerve cell body
organelle
a specialized cell structure that performs a specific job within a cell
carbon dioxide
gas that is a reactant of photosynthesis and a waste product of cellular respiration
antibody
specialized protein made by the body to fight off future infections from a disease-causing organism
transcription
copying the code from DNA onto mRNA
codon
three mRNA nucleotides that code for a specific amino acid
translation
process by which a ribosome uses the code on mRNA to make proteins
nucleotide
building block of a nucleic acid (DNA and RNA)
chromatin
DNA that is coiled around proteins
amino acid
building block of a protein
mRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
polypeptide
synonym for protein; chain of amino acids
replication
process in which DNA is duplicated
rRNA
ribosomal RNA; type of RNA that makes up part of the ribosome
mutation
a change or error in the DNA sequence
tRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
cell division
division of a parent cell into two identical daughter cells
centriole
structure that helps to form the spindle
spindle
microtubule structure that separates chromosomes during mitosis
cell cycle
cell grows, prepares to divide, then divides to start growth process again; interphase + M phase
telophase
last phase of mitosis, chromosome are in two new cells and nuclear membranes start to reform
interphase
cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases
mitosis
division of the nucleus or chromosomes
metaphase
phase of mitosis in which chromosomes line up in the center of the cell
prophase
first phase of mitosis in which chromosomes become visible and nuclear membraine disappears
cytokinesis
division of the cytoplasm (cytosol and organelles)
anaphase
phase of mitosis in which sister chromatids are pulled to opposite sides of the cell
G1 phase
stage of interphase in which cell grows and performs its normal functions
S phase
stage of interphase in which DNA is replicated
G2 phase
stage of interphase in which cell duplicates its cytosol and organelles
gamete
sex cell, sperm or egg
meiosis
type of cell division that creates gametes; cell divides twice to create four cells that are genetically unique
crossing-over
process by which homologous chromosomes exchange pieces, resulting in greater genetic variety
plasma membrane
thin flexible barrier that regulates what enters and exits the cell; composed of two layers of lipids
nuclear envelope
membrane surrounding the nucleus
nucleolus
helps to assemble ribosomes
cytoplasm
material between the cell membrane and the nucleus
mitochondrion
breaks down food to make ATP
endoplasmic reticulum
internal transport system of the cell, modifies proteins, and synthesizes lipids
Golgi apparatus
stack of membranes that modify proteins and creates "packages" to send them to other locations
lysosome
filled with enzymes to breakdown dead cell parts and foreign objects; only found in animal cells
ribosome
synthesizes proteins
vacuole
stores water and nutrients for the cell; very large in plant cells
chloroplast
uses sunlight to make carbohydrates in plants, some bacteria and protists
centriole
organize the spindle fibers to separate chromosomes during animal cell mitosis
cytoskeleton
network of proteins in the cytoplasm that help cell maintain its shape
cilium
hairlike projections that help some cells move
flagellum
whiplike structure some cells use for propulsion
pseudopod
projection of cytoplasm that some protists use for movement and feeding
prokaryote
cell without a nucleus, it contains a cell membrane, cytoplasm, and ribosomes; bacteria
eukaryote
cell with a nucleus and membrane bound organelles; animals, plants, protists, fungi
gene
section of DNA that codes for a protein and determines a trait
trait
specific characteristic that varies from one individual to another
segregation
separation of alleles during meiosis or gamete formation
gamete
sex cell; sperm or egg
true-breeding
inherited two identical alleles for a trait; homozygous or purebred
Punnett square
diagram that shows the possible results of a genetic cross; parents' gametes on top and left, offsprings' genotypes inside
independent assortment
principle that genes do not influence each other's inheritance because they are separated independently during meiosis
multiple alleles
three or more alleles exist for a particular trait
incomplete dominance
creates a blended phenotype; one allele is not completely dominant over the other
polygenic trait
trait controlled by two or more genes; shows a wide variety of phenotypes
codominance
both genes contribute to the phenotype of the organism, ex. spotted or striped
nondisjunction
error in meiosis in which homologous chromosomes don't separate; gametes end up with wrong number of chromosomes
natural variation
differences among individuals of a species; results from mutation and sexual reproduction
adaptation
inherited characteristic that increases an organism's chance of survival
common descent
principle that all living things have a common ancestor
homologous structure
structures that have different mature forms but develop from the same embryonic tissues
vestigial organ
organ so reduced in size, it does not serve an important function; may be homologous to structures in other organisms
species
two organisms that are so similar they can interbreed in nature and produce fertile offspring
speciation
formation of a new species as a result of reproductive isolation
reproductive isolation
separation of species that prevents them from interbreeding and producing fertile offspring
behavioral isolation
type of reproductive isolation in which two organisms have different mating rituals that prevent them from interbreeding
geographic isolation
type of reproductive isolation in which two populations are separated by geographic barries like mountains or bodies of water
temporal isolation
type of reproductive isolation in which two organisms reproduce at different times
biodiversity
variety of organisms that exist in the biosphere
taxonomy
classification of organisms
binomial nomenclature
two part scientfic name for an organism; its genus is listed first, followed by its species
genus
first part of an organism's scientific name
kingdom
second largest taxonomic group; there are six - animalia, plantae, protista, eubacteria, archaebacteria, fungi
domain
most inclusive taxonomic group, larger than kingdom; three exist - bacteria, archaea, eukaryota
Protista
a single celled plant or animal, ex. amoeba, paramecia, euglena
molecular clock
model that uses DNA comparisons to estimate how long two organisms evolved from a common ancestor
phylogenetic tree
diagram showing evolutionary relationships of organisms with a common ancestor; resembles a tree
cladogram
diagram that shows the evolutionary relationships among organisms based on derived characters; resembles a timeline
divergent evolution
pattern of evolution in which two species become more and more dissimilar
Fungi
kingdom of hetertrophs that obtain nutrients through absorption, ex. mushrooms, yeasts
Eukaryota
domain of organisms that contain nuclei, includes animals, plants, fungi, and protists
ecology
study of interactions between organisms and their environment
ecosystem
all the organisms in a particular location, including their non-living environment
species
two organisms that are so similar they can interbreed in nature and produce fertile offspring
population
members of a species in a defined area, smallest level that can evolve
biosphere
part of Earth that living organisms inhabit
community
populations of different organisms living in a defined area
autotroph
organism that makes its own food using sunlight or chemicals; producer
producer
organism that makes its own food using sunlight or chemicals; autotroph
photosynthesis
using sunlight and carbon dioxide to make food (carbohydrates)
chemosynthesis
using inorganic chemicals to make food (carbohydrates)
heterotroph
organism that relies on other organisms for food; consumer
consumer
organism that relies on other organisms for food; heterotroph
decomposer
organism that breaks down and absorbs nutrients from dead organisms
trophic level
step in a food chain, food web, or ecological pyramid
energy pyramid
diagram that shows the energy available to each trophic level in an ecosystem; 10% is passed on to upper levels, the rest is lost as heat
biogeochemical cycle
process in which nutrients are recycled through the biosphere, ex. carbon, nitrogen, and phosphorous
evaporation
process by which liquid water turns into a gas (water vapor) when heated
transpiration
evaporation of water from plant leaves
nutrient
chemical that an organism needs to live
nitrogen fixation
process in which bacteria convert nitrogen gas into nitrogen compounds plants can use to make proteins
denitrification
conversion of nitrates in the soil by bacteria into nitrogen gas
greenhouse effect
heat reatined by the the gases of the Earth's atmosphere to maintain the Earth's temperature range
biotic factor
living factors or organisms that affect an ecosystem
abiotic factor
non-living factor that affects an ecosystem
habitat
where an organism lives
symbiosis
relationship in which two species live closely together
carrying capacity
largest number of individuals of a population that the environment can support
invasive (non-native) species
plants and animals that have migrated to areas where they did not originate; often displace native species by outcompeting them for resources
biodiversity
the variety of all living things in the biosphere
cellular respiration
process that breaks down food to make ATP and release carbon dioxide as waste
chemical bond
link formed by two electrons that binds atoms together; where the energy in a compound is stored
acid
compound that release H+ ions in solution; pH less than 7
base
compound that releases OH- ions in solution; pH greater than 7
monomer
building block or small unit of a polymer; can be linked into chains
polymer
large molecule made up of smaller building blocks or monomers
carbohydrate
contains carbon, hydrogen, and oxygen; main source of energy for body, commonly end in "ose"
monosaccharide
building block of a carbohydrate; simple sugar
polysaccharide
large carbohydrate made up of monosaccharides, ex. starch and glycogen
lipid
huge molecule that contains carbon, hydrogen, and a little oxygen; includes fats, oils, and waxes
fatty acid
with glycerol, make up the building blocks of lipids
glycerol
with fatty acids, make up the building blocks of lipids
RNA
single stranded nucleic acid used for protein synthesis
DNA
double stranded nucleic acid that stores and transmits genetic information
protein
contains carbon, hydrogen, oxygen, and nitrogen; makes up cell/body structures and enzymes
nucleotide
building block or monomer of a nucleic acid; commonly recognized by its nitrogen bases as A, T, C, or G
amino acid
building block or monomer of a protein
nucleic acid
contains carbon, hydrogen, oxygen, nitrogen, and phosphorous; involved in protein synthesis
chemical reaction
process that changes one set of chemicals into another set of chemicals
reactant
chemical that enters a chemical reaction
product
chemical that results from a chemical reaction
activation energy
energy needed to start a reaction
catalyst
substance that speeds up the rate of a chemical reaction
enzyme
specialized protein that speeds up a chemical reaction by decreasing activation energy; typically end in "ase"
substrate
reactant in a chemical reaction that happens in a living thing
denaturation
when an enzyme changes shape and no longer functions due to high temperatures or wrong pH
organic compound
compound that contains carbon bonded to hydrogen and is found in living things
starch
polysaccharide made up of a chain of glucose molecules; food storage molecule for plants
glycogen
compound used by animals to store carbohydrates in the liver and skeletal muscles
glucose
simple sugar that is used to make ATP through cellular respiration
cellulose
polysaccharide that is the main component of plant
hemoglobin
specialized protein that carries oxygen on red blood cells
insulin
protein hormone that helps to decrease blood sugar
cholesterol
specialized lipid that is used in cell membranes and making hormones
digestive system
body system the breaks down food and absorbs nutrients
pharynx
the throat; last place food and air mix
esophagus
muscular tube connecting the pharynx to the stomach
stomach
muscular sac that churns food and secretes hydrochloric acid to start breaking down proteins
small intestine
organ that completes the chemical digestion of food and absorbs the nutrients
large intestine
organ that absorbs water from undigested material
chemical digestion
the digestion process in which enzymes are used to break foods into their smaller chemical buiding blocks
mechanical digestion
the physical breakdown of food into smaller pieces
rectum
the lower part of the large intestine where feces are stored
circulatory system
body system consisting of the heart and blood vessels that circulate blood through the body
artery
thick-walled muscular blood vessel that carries blood away from the heart
vein
blood vessel that carries blood toward the heart when pumped by skeletal muscles
capillary
tiny, thin-walled blood vessel where substances (gases and nutrients) are exchanged between the blood and the body cells
red blood cells
blood cells containing hemoglobin that carry oxygen through the bloodstream
respiratory system
system responsible for taking in oxygen and releasing carbon dioxide using the lungs
skeletal muscle
voluntary, striated, multi-nucleate muscle that moves bones
smooth muscle
involuntary muscle found in internal organs
cardiac muscle
type of muscle found in the heart which generates its own electrical signal to contract
ligament
band of connective tissue that holds the bones together
tendon
a band of fibrous tissue that connects muscle to bone
endocrine system
collection of glands that secrete hormones into the blood which regulate growth, development, and homeostasis
hormone
chemical messengers secreted by glands into the blood
nervous system
consists of brain, spinal cord, and nerves and regulates the body's responses to internal and external stimuli
homeostasis
the process by which organisms keep their internal environment relatively stable
negative feedback loop
an opposite action to what is occurring in the body to regain homeostasis, ex. if body temperature rises too high, body tries to lower it
diffusion
movement of molecules across a membrane from high to low concentration without energy
concentration gradient
difference in concentration of a substance on two sides of a membrane
osmosis
movement of water across a membrane from high to low concentration without energy
semi-permeable
characteristic of a cell membrane which allows some molecules to pass through but not others
impermeable
molecules are not able to pass through the membrane
facilitated diffusion
movement of molecules through protein channels in the membrane from high to low concentration
active transport
movement of molecules through protein channels in the membrane from low to high concentration requiring energy (ATP)
passive transport
movement of molecules across a membrane from high to low concentration without energy, ex. diffusion, osmosis, facilitated diffusion
Covalent Bond
a chemical bond that involves sharing a pair of electrons between atoms in a molecule
Hydrogen Bond
a chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond
organelle
structure that performs a specific function WITHIN a cell. (Kind of like how organs perform within your body).
isotopes
atoms of the same element that differ in the number of neutrons they contain
Radioactive isotope
the necleus decays, giving off particles and energy. Can harm living organisms by damaging cellular molecules
Neutron
an elementary particle with 0 charge and mass about equal to a proton
Proton
a stable particle with positive charge equal to the negative charge of an electron
Electron
an elementary particle with negative charge
chemical bonds
an attraction between two atoms resulting from the sharing of outer-shell electrons or the presence of opposite charges
ionic bond
a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
double bond
a covalent bond in which two pairs of electrons are shared between two atoms
electronegativity
(chemistry) the tendency of an atom or radical to attract electrons in the formation of an ionic bond
nonpolar covalent bond
covalent bond where electrons are shared equally
polar molecule
a molecule in which the charges are unevenly distributed
polar covalent bond
the pair of electrons is shared however one atom has those electrons more than the other one does. A "unequal sharing."
Cohesion
(physics) the intermolecular force that holds together the molecules in a solid or liquid
Adhesion
an attraction between molecules of different substances
Extracellular matrix
nonliving material between cells
Tight Junctions
outermost cell junctions in epithelium (common name)
Anchoring Junctions
cell junction; rivets cells together with cytoskeletal fibers; forms strong sheets
Gap Junctions
cell junctions that are holes
hydrophilic Heads
Refers to the portion of the phospholipid that contains the phosphate group (and possibly the choline group as well). These charged groups are hydrophilic, unlike the nonpolar fatty acids tails.
Hydrophobic tails
water-fearing
Concentration gradient
the path molecules travel when an imbalance between separated molecule concentrations exists
Diffusion
The tendency of molecules of any substance to spread out evenly into the available space.
Isotonic
a solution with the same salt concentration by equal osmotic pressure
Hypotonic
(of a solution) having a lower osmotic pressure than a comparison solution
Hypertonic
(of a solution) having a higher osmotic pressure than a comparison solution
osmosis
diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal
membrane
a pliable sheet of tissue that covers or lines or connects organs or cells of animals
Resting Potential
the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse
exocytosis
the cell secretes macromolecules by the fusion of vesicles with the plasma membrane
endocytosis
the cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane
Oxidation
A chemical reaction in which an atom loses one or more electrons.
reduction
any process in which electrons are added to an atom or ion (as by removing oxygen or adding hydrogen)
Aerobic Respiration
what is the type of metabolism that occurs in the presence of oxygen and produces 38 molecules of ATP?
Anaerobic Respiration
Respiration in the absence of oxygen. This produces lactic acid.
ATP
a nucleotide derived from adenosine that occurs in muscle tissue
Electron Transport Chain
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.