Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Biology Vocabulary

Biology Vocabulary Words

Biology the study of life
Cells Highly organized, tiny structures with thin membrane coverings. The basic unit of biology.
Evolution Change in the inherited traits of species over generations.
Reproduction Process by which organisms make more of their own kind from one generation to the next.
Metabolism The sum of all chemical reactions carried out in an organism.
Homeostasis The maintenance of a stable internal environment.
Gene Sections of chromosomes made of DNA that code for traits. The basic unit of heredity.
Heredity The passing of traits from parent to offspring.
Mutation A change in the DNA of a gene.
Species A group of genetically similar organisms that can produce fertile offspring.
Natural Selection Process in which organisms with favorable genes are more likely to survive to reproduce.
Ecology The branch of biology that studies the interactions of ogranisms with one another and with nonliving part of their environment.
Genome The complete genetic material contained in an individual.
HIV A virus that attacks and destroys the human immune system.
Cancer A growth defect in cells , a breakdown of the mechanism that controls cell division.
Cystic Fibrosis A fatal disorder in which a thick, sticky mucus clogs passages in many of the body's organs.
Gene Therapy The replacement of a defective gene with a normal version.
Observation The act of noting or perceiving objects or events using senses.
Hypothesis An explanation that might be true
Prediction The expected outcome of a test, assuming the hypothesis is correct.
pH A relative measure of the hydrogen ion concentration within a solution.
Experiment A planned procedure to test a hypothesis.
Atom The smallest unit of an element that maintains the properties of that element.
Element A substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number.
Compound A substance made up of atoms of two or more different elements joined by chemical bonds.
Molecule The smallest unit of a substance that keeps all of the physical and chemical properties of that substance; it can consist of one atom or two or more atoms bonded together.
Ion An atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge.
Cohesion The force that holds molecules of a single material together.
Adhesion The attractive force between two bodies of different substances that are in contact with each other.
Solution Homogeneous mixture of two or more substances uniformly dispersed throughout a single phase.
Acid Any compound that increases the number of hydronium ions when dissolved in water; acids turn blue litmus paper red and reacts with bases and some metals to form salts.
Base Any compound that increases the number of hydroxide ions when dissolved in water; bases turn red litmus paper blue and react with acids to form salts.
Carbohydrate Any organic compound that is made of carbon, hydrogen, and oxygen and that provides nutrients to the cells of living things.
Monosaccharide A simple sugar that is the basic subunit of a carbohydrate.
Lipid A type of biochemical that does not dissolve in water, including fats and steroids; lipids store energy and make up cell membranes.
Protein A large molecule formed by linked smaller molecules called amino acids.
Amino Acid The building blocks of proteins.
Nucleic Acid An organix compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information.
Nucleotide In a nucleic-acid chain, a subunit that consists of a sugar, a phosphate, and a nitrogenous base.
DNA deoxyribonucleic acid, the material that contains the information that determines inherited characteristics
RNA ribonucleic acid, a natural polymer that is present in all living cells and that plays a role in protein synthesis
ATP adenosine triphosphate, is a single nucleotide with two extra energy-storing phosphate groups
Energy the capacity to do work.
Activation Energy The minimum amount of energy required to start a chemical reaction.
Enzyme A type of protein that speeds up metabolic rxns in plants and animals without being permanently changed or destroyed.
Substrate A part, substance or element that lies beneath and supports another part, substance, or element; the reactant in rxns catalyzed by enzymes.
Active Site The site on an enzyme that attaches to a substrate.
Light Microscope A microscope that uses a beam of visible light passing through one or more lenses to magnify an object.
Electron Microscope A microscope that fouses a beam of electrons to magnify objects.
Magnification The increase of an object's apparent size by using lenses or mirrors.
Resolution In microscopes, the ability to form images with fine detail.
Scanning Tunneling Microscope A microscope that uses a needle-like probe to measure differences in voltage caused by electrons that leak, or tunnel, from the surgace of the object being viewed.
Cell Theory The theory that states that all living things are made up of cells, that celss are the basic units of organisms, that each cell in a multicellular organism has a specific job, and that cells come only from existing cells.
Cell Membrane A phospholipid layer that covers a cell's surface and acts as a barrier between the inside of a cell and the cell's environment.
Cytoplasm The region of the cell within the membrane that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus.
Cytoskeleton The cytoplasmic network of protein filaments that plays an essential role in cell movement, shape and division.
Ribosome A cell organelle composed of RNA and protein, the site of protein synthesis.
Prokaryote An organism that consists of a single cell that does not have a nucleus or cell organelles; an example is bacterium.
Cell Wall A rigid structure that surrounds the cell membrane and provides support to the cell.
Flagellum A long, hairlike structure that grows out of a cell and enables the cell to move.
Eukaryote An organism made up of cells that have a nucleus enclosed by a membrane, multiple chromosones, and a miotic cycle; eukaryotes include animals, plants and fungi but not bacteria or cyanobacteria.
Nucleus In a eukaryotic cell, biology, a membrane-bound organelle that contains the cell's DNA and that has a role in processes such as growth, metabolism and reproduction.
Organelle One of the small bodies that are found in the cytoplasm of a cell and that are specialized to perfrom body functions.
Cilium A hairlike structure arranged in tightly packed rows that projects from the surface of some cells.
Phospholipid A lipid that contains phosphorus and that is a structural component in cell membranes.
Lipid Bilayer The basic structure of a biological membrane, composed of two layers of phospholipids.
Endoplasmic Reticulum A system of membranses that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids.
Vesicle A small cavity or sac that contains materials in a eukaryotic cell; forms when part of the cell membrane surrounds the materials to be taken into the cell or transported within the cell.
Golgi Apparatus Cell organelle that helps make and package materials to be transported out of the cell.
Lysosome A cell organelle that contains digestive enzymes.
Mitochondrion In eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site of cellular respiration, which produces ATP.
Chloroplast An organelle found in plant and algae cells where photosynthesis occurs.
Central Vacuole A large cavity or sac that is found in plants or protozoans and that contains air or partially digested food.
Passive Transport The movement of substances across a cell membrane without the use of energy by the cell.
Concentration Gradient A difference in the concentration of a substance across a distance.
Equilibrium In chemistry, the state in which a chemical reaction and the reverse chemical reaction occur at the same rate such that the concentrations of reactancts and products do not change.
Diffusion The movement of particles from regions of higher density to regions of lower density.
Osmosis The diffusion of water or another solvent from a more dilute solution (of a solute) to a more concentrated solution (of the solute) through a membrane that is permeable to the solvent.
Hypertonic Solution A solution that causes a cell to shrink because of osmosis.
Hypotonic Solution A solution that causes a cell to swell because of osmosis.
Isotonic Solution A solution whose solute concentration is equal to the solute concentration inside a cell.
Ion Channel A pore in a cell membrane through which ions can pass.
Carrier Protein A protein that transports substances across a cell membrane.
Facilitated Diffusion The transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins.
Active Transport The movement of chemical substances, usually across the cell membrane, against a concentration gradient; requires cells to use energy.
Sodium-Potassium Pump A carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell.
Endocytosis The process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell.
Exocytosis The process by which a substance is released from the cell through a vesivle that transports the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out.
Receptor Protein A protein that binds specific signal molecules, which causes the cell to respond.
Second Messenger A molecule that is generated when a specific substance attaches to a receptor on the outside of a cell membrane, which produces a change in cellular function.
Photosynthesis The process by which plants, algae, and some bacteria use sunlight, carbon dioxide and water to produce carbohydrates and oxygen.
Autotroph An organism that produces its own nutrients from inorganic substances or from the environment instead of cosuming other organisms.
Heterotroph An organism that obtains organic food molecules by eating other organisms or their by products and that cannot synthesize organic compounds from inorganic materials.
Cellular Respiration The process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide.
Pigment A substance that gives another substance or mixture its color.
Chlorophyll A green pigment that is present in most plant cells, that gives plants their characteistic green color, and that reacts with sunlight, carbon dioxide and water to form carbohydrates.
Carotenoid A class of pigments that are present mostly in plants and that aid in photosynthesis.
Thylakoid A membrane system found within chloroplasts that contains the components for photosynthesis.
Electron Transport Chain A series of molecules found in the inner membranes of mitochondria and chloroplasts, through which electrons pass in a process that causes protons to build up on one side of the membrane.
NADPH An electron carrier that provides the high-energy electrons needed to make carbon-hydrogen bonds in the third stage of photosynthesis.
Carbon Dioxide Fixation The synthesis of organic compounds from carbon dioxide, such as in photosynthesis.
Calvin Cycle A biochemical pathway of photosynthesis in which carbon dioxide is converted into glucose using ATP.
Aerobic Describes a process that requires oxygen.
Anaerobic Describes a process that does not require oxygen.
Glycolysis The anaerobic breakdown of glucose pyruvic acid, which makes a small amount of energy available to cells in the form of ATP.
NADH the electron carrier formed as glucose is broken down, some of its hydrogen atoms are transferred to an electron called NAD+.
Krebs Cycle A series of biochemical reactions that convert pyruvic acid into carbon dioxide and water; it is the major pathway of oxidation in animal, bacterial and plant cells and it releases energy.
FADH2 Electrons are transferred to an electron acceptor called FAD, making a molecule of this.
Fermentation The breakdown of carbohydrates by enzymes, bacteria, yeasts, or mold in the absence of oxygen.
Created by: stefanseul



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards