| acetylcholine |
chemical signaling molecule |
| acetylcholinesterase |
enzyme that breaks down acetylcholine |
| acid |
chemical that gives off hydrogen ions |
| adenine |
molecule found in DNA and RNA; pairs with thymine (in DNA) or uracil (in RNA) |
| adipocyte |
fat cell |
| aerobic |
activity that occurs when oxygen is plentiful |
| alcohol |
chemical group that includes grain alcohol, ethanol (EtOH) |
| alkaline |
chemical that absorbs hydrogen ions |
| allele |
unit of inheritance |
| amphipathic |
a molecule that partially prefers water and partially repels water |
| anabolic |
chemical process that makes larger chemicals out of smaller ones |
| anaerobic |
activity that occurs when oxygen is scarce |
| anaphase |
stage of cell division where chromosomes are separating |
| antibody |
protein that defends the body against invaders; immunoglobulin |
| antiparallel |
parallel, but running in opposite directions, like a two-lane road |
| antiport |
transport process that involves molecules moving in opposite directions; exchange |
| apical |
toward the top |
| apocrine |
cellular secretion that involves breaking off a piece of the cell |
| apoptosis |
programmed or preplanned cell death |
| astrocyte |
star-shaped cell of the brain; a type of glial cell (same as astroglia) |
| astroglia |
star-shaped cell of the brain; a type of glial cell (same as astrocyte) |
| atom |
the smallest unit of matter; indivisible quantity (name means "can't be cut") |
| autosome |
chromosome that is not involved in sex determination |
| avascular |
without blood vessels |
| basal |
toward the bottom |
| base pair |
adenine-thymine or cytosine-guanine pairs that form the "rungs" of the twisted ladder structure of DNA |
| bilayer |
two-layered covering; cell membrane |
| blastocyst |
stage of a human embryo where it is a hollow ball of rapidly-dividing cells |
| carbohydrate |
molecule consisting of equal parts carbon and water |
| catabolic |
chemical process that makes smaller chemicals out of larger ones |
| catalyze |
to speed up a chemical reaction |
| centriole |
organelle that acts as a microtubule organizing center (MTOC) |
| centromere |
part of a chromosome in the center, where the two DNA molecules touch |
| centrosome |
organelle that acts as a microtubule organizing center (MTOC) |
| cholesterol |
important lipid, essential for cell processes |
| chondrocyte |
cartilage cell |
| chromatin |
DNA plus RNA plus associated proteins, visible when cells are dyed and viewed through the microscope |
| chromosome |
chromatin visible through the microscope in X-shaped packages |
| cilia |
eyelash-like extension of the cell, used to move substances on the cell surface |
| codon |
unit of genetic information; thousands of codons make up a gene |
| colloid |
microscopic particles (larger than molecules) surrounded by water |
| columnar |
cells that are higher than they are wide |
| cuboidal |
cells that are about as high as they are wide ("cube-like") |
| cytokinesis |
the movement of cells in cell division |
| cytoplasm |
gel-like substance, including organelles, that fills cells and is surrounded by a membrane |
| cytosine |
molecule found in DNA and RNA; pairs with guanine |
| cytoskeleton |
organelle composed of structural support proteins |
| cytosol |
cytoplasm minus organelles |
| dehydration |
chemical reaction which removes water and forms a new chemical bond |
| denaturation |
using heat or chemicals to alter the normal (native) structure of proteins, DNA, or RNA |
| deoxyribose |
a sugar that, along with phosphate groups, forms the backbone of the DNA molecule |
| diffusion |
process by which molecules move from areas of high concentration to areas of low concentration |
| diploid |
containing two copies of each DNA molecule; the normal number of DNA molecules in most human cells |
| dominant |
in Mendelian genetics, one copy of a dominant allele is expressed as an observable characteristic |
| elastin |
a protein; snaps back into shape when released after being stretched |
| electrolysis |
process of breaking molecules (or hairs) through electricity |
| electrolyte |
charge-carrying ion in the blood |
| electromagnetic |
radiation that depending on energy level can be radio waves, microwaves, visible light, X-rays, or gamma rays |
| electron |
subatomic particle with a negative charge; found on the outside of the atom |
| endergonic |
chemical reaction which requires energy |
| endocytosis |
intake of substances by the cell |
| endoplasmic reticulum |
organelle with net-like structure found in cytoplasm |
| endothelium |
tissue lining blood vessels |
| endothermic |
chemical reaction which absorbs heat energy; same thing as endergonic |
| entropy |
the tendency of matter to become disorganized |
| enzyme |
protein that speeds up chemical reactions in the cell |
| epigenetic |
changes in DNA that are outside of the normal molecular genetic processes |
| epinephrine |
chemical signaling molecule |
| epithelium |
tissue lining body cavities and outside surfaces of the body |
| erythrocyte |
red blood cell |
| erythrocytosis |
abnormally high levels of red blood cells |
| estrogen |
lipid signaling molecule that promotes development of female sexual characteristics |
| ethanol |
alcohol that forms part of liquor, wine, and beer; grain alcohol |
| euchromatin |
unspooled chromatin; chromatin in the active process of being used |
| eukaryotic |
cells with a true nucleus |
| exergonic |
chemical reaction which releases energy |
| exocytosis |
release of substances from a cell |
| exon |
the part of a gene that is turned into protein |
| exothermic |
chemical reaction which releases heat energy; same thing as exergonic |
| extracellular |
outside of cells |
| fibroblast |
connective tissue cell |
| fructose |
a sugar; converted by liver to glucose |
| gamete |
eggs in females and sperm in males; the cells specialized for reproduction |
| gastrulation |
process of embryonic development that forms a "little stomach" or invagination |
| genotype |
silent characteristic of DNA that results from the sequence of DNA base pairs |
| glia |
non-excitable cells of the brain; perform housekeeping duties for the brain |
| gluconeogenesis |
process by which new glucose molecules are made inside the body |
| glucose |
a sugar; main energy carrier in blood |
| glycerol |
alcohol derived from sugar |
| glycogen |
storage form of glucose, mostly found in liver and muscle |
| glycogenolysis |
breakdown of glycogen |
| glycolysis |
breakdown of glucose |
| glycoprotein |
protein + sugar; more protein than sugar |
| goblet cell |
mucus-making cell |
| guanine |
molecule found in DNA and RNA; pairs with cytosine |
| haploid |
containing one copy of each DNA molecule; the normal number of DNA molecules in gametes |
| hemoglobin |
protein that carries oxygen and CO2 in the blood |
| heterochromatin |
spooled chromatin; chromatin in storage |
| histology |
the study of tissues |
| histone |
protein spool around which DNA is wound |
| holocrine |
cellular secretion that involves the cell exploding |
| hydrolysis |
chemical reaction which adds water and breaks a chemical bond |
| hydrophilic |
a molecule that prefers water |
| hydrophobic |
a molecule that repels water |
| hypercholesterolemia |
high cholesterol levels in the blood |
| hyperkalemia |
high potassium levels in the blood |
| hypernatremia |
high sodium levels in the blood |
| hypertonic |
solution with more particles per volume than the inside of a cell |
| hypokalemia |
low potassium levels in the blood |
| hyponatremia |
low sodium levels in the blood |
| hypotonic |
solution with fewer particles per volume than the inside of a cell |
| immunoglobulin |
protein that defends the body against invaders; antibody |
| insulin |
protein that helps cells manage blood sugar |
| interphase |
stage of cell life cycle that does not involve active division |
| intron |
the part of a gene that is discarded in protein synthesis |
| ionic |
pertaining to charged particles (atoms or molecules) |
| isomer |
different arrangements of the same atoms in the same quantities |
| isotonic |
solution with the same number of particles per volume as the inside of a cell |
| isotope |
different forms of the same element where the number of neutrons varies but the number of protons stays the same |
| ketoacidosis |
high ketone and acid levels in the blood |
| ketone |
chemical byproduct of lipid breakdown |
| kinase |
enzyme that adds a phosphorus-containing chemical group |
| lactose |
a sugar; found in milk |
| lamina |
layer; "plate" |
| lariat |
loop of RNA that is discarded as an intron |
| leukocyte |
white blood cell |
| leukocytosis |
abnormally high levels of white blood cells |
| ligand |
a signaling molecule or drug that binds a receptor |
| lipoprotein |
a protein that carries fat molecules in the blood |
| liposome |
microscopic balls of fat molecules |
| lymphocyte |
white blood cell (a subtype) |
| lysosome |
organelle that breaks down substances that the cell no longer needs |
| macrophage |
cell that eats large particles, including bacterial invaders |
| maltose |
a sugar; derived from malt |
| meiosis |
process of forming gametes by reorganizing and reducing the amount of DNA in each cell |
| merocrine |
cellular secretion that involves the cell releasing substances using vesicles |
| metabolism |
anabolism + catabolism |
| metaphase |
stage of cell division where chromosomes are lined up |
| microfilament |
thread-like part of the cytoskeleton |
| microglia |
defensive cell in the brain |
| microtubule |
tube-like part of the cytoskeleton |
| microvillus |
microscopic shaggy hair-like structures on the surface of intestinal cells and other absorptive epithelia |
| mitochondrion |
organelle that creates cellular energy |
| mitosis |
process of cell division that results in diploid cells (non-gamete cells; somatic cells) |
| mole |
unit describing number of molecules in a solution |
| molecule |
arrangements of two or more atoms into larger structures (typically, about one-thousandth of a millimeter) |
| monomer |
single molecular unit |
| neutron |
subatomic particle with no charge; found in the nucleus of the atom |
| norepinephrine |
chemical signaling molecule |
| nucleolus |
"little nucleus": RNA-making factory in the nucleus of a cell |
| nucleoside |
part of DNA and RNA: base (adenine, cytosine, guanine, thymine, or uracil) plus sugar |
| nucleotide |
monomer of DNA or RNA; nucleoside plus 1 phosphorus and 4 oxygen atoms |
| nucleus |
organelle where genetic material is stored and manipulated |
| oligodendrocyte |
a cell in the nervous system that forms insulating sheaths; same as oligodendroglia |
| oligodendroglia |
a cell in the nervous system that forms insulating sheaths; same as oligodendrocyte |
| organelle |
microscopic part of a cell where specific cell functions are carried out |
| osmosis |
process of diffusion through a membrane that only allows water to pass |
| osteocyte |
bone cell |
| parenchyma |
the proper tissue of an organ (as distinguished from connective tissue, blood vessels, etc.) |
| peptidoglycan |
sugar + protein; more sugar than protein |
| peroxide |
water with an extra oxygen atom; H2O2 |
| peroxisome |
organelle that uses peroxide to break down substances in the cell |
| phagocytosis |
process of cell eating large particles |
| phenotype |
observable characteristic that results from genetic plus epigenetic processes |
| phospholipid |
phosphorus-containing fat molecule |
| phosphorylation |
process of removing a phosphorus-containing chemical group |
| photon |
subatomic particle that carries electromagnetic (light) energy |
| pinocytosis |
process of cell drinking |
| ploidy |
number of DNA molecules in the cell |
| polar |
molecule with an unequal distribution of electrons; this makes it water-loving (hydrophilic) |
| polymer |
combination of two to 250 million molecular units |
| polypeptide |
small protein; string of many amino acids (generally, between 2 and 100ish) |
| polyploid |
containing more than two copies of each DNA molecule |
| primer |
a DNA or RNA fragment that starts a chemical process in the cell |
| prokaryotic |
cells without a true nucleus |
| prophase |
stage of cell division that begins the division process |
| prostaglandin |
lipid signaling molecule |
| proteasome |
organelle that breaks down proteins that the cell no longer needs |
| protein |
a string of amino acids which is responsible for most cell functions (generally, between 100 and 34,350 amino acids) |
| proteoglycan |
sugar + protein; more sugar than protein |
| proton |
subatomic particle with a positive charge; found in the nucleus of the atom |
| pseudostratified |
appearing to be layered when there is actually a single layer of cells |
| receptor |
a protein in the cell membrane; when it binds a signaling molecule it causes a change in the cell |
| recessive |
in Mendelian genetics, two copies of a recessive allele are needed to create an observable characteristic |
| renaturation |
restoring the normal (native) structure of proteins, DNA, or RNA |
| resonance |
property of molecules where there is extensive sharing of electrons between atoms |
| reticular |
net-like |
| ribose |
a sugar that, along with phosphate groups, forms the backbone of the RNA molecule |
| ribosome |
organelle that is a protein-making machine; consists of RNA plus protein |
| secretion |
release of substances from a cell or from the body |
| solution |
molecular-size particles surrounded by water |
| somatic |
most of the body cells; cells that have no reproductive function (non-gametes) |
| squamous |
cells that are wider than they are high |
| steroid |
lipid signaling molecule based on cholesterol |
| stratified |
layered |
| stratum |
layer |
| substrate |
molecule that an enzyme acts upon |
| sucrose |
a sugar; cane sugar or table sugar |
| surfactant |
chemical substance that helps lipids dissolve in water; detergent |
| suspension |
cells or other large microscopic particles surrounded by water |
| symport |
transport process that involves molecules moving in the same direction |
| telomere |
part of a chromosome at the ends |
| telophase |
stage of cell division that ends the division process |
| testosterone |
lipid signaling molecule that promotes development of male sexual characteristics |
| thermodynamics |
branch of physics that studies how energy is managed by systems like cells |
| thrombocyte |
cell fragment responsible for blood clotting; platelet ("small plate") |
| thrombocytopenia |
abnormally low levels of thrombocytes |
| thrombocytosis |
abnormally high levels of thrombocytes |
| thymine |
molecule found in DNA; pairs with adenine |
| tonicity |
number of particles per unit volume (i.e. concentration of particles) |
| transcription |
process by which RNA is made from DNA |
| translation |
process by which protein is made from RNA |
| triglyceride |
form of lipid found in the blood |
| uracil |
molecule found in RNA; pairs with adenine |
| valence |
property of atoms important to understand formation of bonds by sharing or trading of electrons |
| vesicle |
organelle that contains molecules to be secreted or absorbed by the cell |
| villus |
shaggy hair-like structures lining the intestines |
