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51 terms

Biology definition

MCAT
STUDY
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organisms
An individual living thing
prokaryotes
unicellular organisms lacking a nucleus and other membrane-bound organelles; circular DNA
Archaea
domain of prokaryotic organisms that are biochemically and genetically distinct from bacteria
Bacteria
domain of unicellular prokaryotes that have cell walls containing peptidoglycans
Halobacterium
halophilic archaea, lives where there's high salt concentrations
pigments
light absorbing molecules
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
species
a group of organisms so similar to one another that they can breed and produce fertile offspring
osmosis
diffusion of water through a selectively permeable membrane
Deinococcus radiodurans
Super bacterium that survives extreme conditions & also survives 3000x more radiation than humans can.
Picrophilus oshimae
Extremophile: Grow in pH of 0.3, acidic enough to dissolve metal
unicellular
having or consisting of a single cell
Thiomargarita namibiensis
Ocean dwelling bacterium. Largest bacterium discovered. Can be seen with naked eye.
cellulose
A structural polysaccharide of cell walls, consisting of glucose monomers joined by b-1, 4-glycosidic linkages.
chitin
complex carbohydrate that makes up the cell walls of fungi; also found in the external skeletons of arthropods
peptidoglycan
A protein-carbohydrate compound that makes the cell walls of bacteria rigid
polymer
large compound formed from combinations of many monomers
monomers
small building block molecules
molecules
Groups of two or more atoms held together by chemical bonds
atoms
building blocks of matter
matter
anything that has mass and takes up space
lipopolysaccharides
large molecules consisting of a lipid and a polysaccharide joined by a covalent bond. Found in the outer membrane of gram-negative bacteria
fever
elevated body temperature
shock
A condition in which the circulatory system fails to provide sufficient circulation to enable every body part to perform its function; also called
hypoperfusion
...
Staphylococcus aureus
a form of staphylococci that commonly infects wounds and causes serious problems such as toxic shock syndrome or produces food poisoning
slime
layer
gelatinous sheath surrounding the cell walls of certain bacteria
Thylakoid
saclike photosynthetic membrane found in chloroplasts
pilus
short, thick outgrowth of a bacterium that allows it to attach to another bacterium
exaptation
a structure that evolves and functions in one environmental context but that can perform additional functions in a new environment
erythromycin
antibiotic
tetracycline
an antibiotic (trade name Achromycin) derived from microorganisms of the genus Streptomyces and used broadly to treat infections
binary fission
type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells
cell-surface proteins
proteins embedded in the cell membrane
bacteriophages
A virus that infects bacteria; also called a phage.
DNA recombination
Combing segments of DNA from at least two diffrent organisms.
conjugation,
A temporary union of two organisms for the purpose of DNA transfer
F factor
A plasmid that codes for the pilus and other genes needed for DNA
copy and transfer in conjugation; short for "fertility factor."
Shigella
rod-shaped gram-negative enterobacteria, -food poison, shigellosis
phototrophs
an organism that uses light energy to generate ATP and produce organic compounds from inorganic substances.
chemotrophs
obtain energy from chemicals
autotrophs
..., organisms that get their carbon directly from the inorganic molecule carbon dioxide
heterotrophs
..., Organisms that depend on other organisms for their food
photosynthetic cells
Cells near the surface of the green parts of stems and leaves that contain large numbers of chloroplasts.
Photoheterotroph:
an organism that uses Light energy to generate ATP and obtains organic compounds from other organisms.
Chemoautotroph:
an organism that uses energy from chemical reactions to generate ATP and produce organic compounds from inorganic substances.
heterocysts
specialized cells that produce nitrogen-fixing enzymes
phylogeny
the study of evolutionary relationships among organisms
molecular systematics
the discipline that uses DNA and other molecular data to determine evolutionary relationships
taxonomy
The scientific study of how living things are classified
metagenomics
the practice of analyzing DNA from environmental samples without isolating intact organisms