Unit 3 Word List
| Word | Definition |
|---|---|
| acetylation | addition of an acetyl group |
| acetylcholine | chemical signaling molecule |
| acetylcholinesterase | enzyme that breaks down acetylcholine |
| acid | chemical that gives off hydrogen ions |
| acidic | quality of being acid |
| 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 |
| albumin | protein found in egg white; major blood protein |
| alcohol | chemical group that includes grain alcohol, ethanol (EtOH) |
| alkali | chemical that absorbs hydrogen ions |
| alkaline | quality of being alkali |
| 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 |
| androgen | lipid signaling molecule that promotes development of male sexual characteristics |
| 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) |
| chimera | animal that is a mixture of two genetic types |
| 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 |
| endogenous | coming from inside |
| 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 |
| exogenous | coming from outside |
| 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 |
| Gram stain | a staining technique used to classify bacteria by their microscopic appearance |
| 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 |
| histological | pertaining to the study of tissues |
| histology | study of tissues |
| histone | substance found in tissues that binds to DNA |
| histopathology | study of how tissues change during disease |
| 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 |
| megakaryocyte | literally, "cell with a large nucleus"; breaks into fragments which help in blood clotting (platelets, also called thrombocytes) |
| 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 |
| methylation | addition of a methyl (–CH3) group |
| 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 |
| mycoplasma | type of bacterium that causes "walking pneumonia" and genital infections |
| mycosis | process involving a fungus; fungal disease |
| 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 |
| platelet | cell fragment responsible for blood clotting; thrombocyte |
| 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 |
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