General Biology Lecture Practice Flashcards

Vocabulary flashcards covering core biological concepts, biological chemistry, cellular structures, membrane transport, photosynthesis, and cellular respiration.

Homeostasis

The maintenance of a stable internal environment, such as keeping blood protein levels strictly between $6.0$ and $8.0\,\text{grams/ml}$ or maintaining resting ion concentration gradients in neurons.

Responsiveness

The ability of an organism to sense and react to environmental changes or stimuli, such as a plant dropping its leaves as night length increases or an animal initiating a fight-or-flight response.

Metabolism

The sum total of all chemical processes occurring within an organism, including photosynthetic energy capture and food digestion to produce ATP.

Adaptation

An inherited feature or process resulting from natural selection over time that alters a population's genetic makeup to improve survival in an environment.

Complex Organization

The structural biological hierarchy where atoms combine to form molecules, which in turn combine to form cells, tissues, organs, and organ systems.

Kingdom Protista

A biological kingdom consisting of single-celled eukaryotic organisms that can be either autotrophs or heterotrophs.

Atomic Number

The number of protons found in the nucleus of an atom, which uniquely identifies a chemical element.

Isotope

Atoms of the same element that share the same atomic number (number of protons) but have different atomic masses due to varying numbers of neutrons.

Ion

An atom or group of atoms that has gained or lost one or more electrons, giving it a net positive or negative charge.

Isomer

Molecules that share the exact same empirical (chemical) formula but differ in their structural formulas.

Hypothesis

A plausible or tentative explanation for an observed phenomenon that can be tested through experimentation.

Scientific Theory

A comprehensive explanation encompassing the outcomes of many tested hypotheses and experiments across a field of research.

Hydrolysis Reaction

An exergonic, energy-releasing chemical reaction in which larger molecules (carbohydrates, lipids, proteins) are broken down using consumed water molecules.

Condensation (Dehydration) Reaction

An endergonic, energy-consuming chemical reaction in which smaller monomer units join together to form larger polymers while releasing water.

Phagocytosis

The cellular process by which leukocytes consume bacteria, viruses, or other foreign pathogens using pseudopodia prior to destroying them with lysosomal enzymes.

Osmosis

The net movement of water molecules from an area of high water concentration to an area of low water concentration across a membrane.

Hemolysis

The swelling and eventual bursting of an erythrocyte (red blood cell) when exposed to a hypotonic solution.

Crenation

The shrinkage of an erythrocyte when placed into a hypertonic solution.

Plasmolysis

The shrinkage of plant cell cytoplasm away from its cell wall when placed in a hypertonic environment.

Turgor

The swollen, rigid condition of a plant cell cytoplasm pressed against its cell wall when placed in a hypotonic solution.

Lysosome

An organelle in eukaryotic cells containing digestive enzymes used to break down cellular waste materials and ingested pathogens.

Mitochondria

Cellular organelles responsible for aerobic respiration, converting glucose in the presence of oxygen into ATP along with carbon dioxide and water.

Chloroplasts

Organelles in plants and photoautotrophs where light energy, carbon dioxide, and water are converted into organic compounds such as glucose, releasing oxygen.

Stomata

Microscopic openings on leaf surfaces that regulate gas exchange, releasing water vapor and oxygen during the day and carbon dioxide at night.

Glycolysis

The initial metabolic process occurring in cytosol that breaks down one glucose molecule into two pyruvic acids, producing a net yield of $2\,\text{ATP}$ and $2\,\text{NADH}$.

Krebs Cycle (Citric Acid Cycle)

The aerobic pathway taking place in the inner compartment of mitochondria that produces $1\,\text{ATP}$, $1\,\text{FADH}_2$, and $3\,\text{NADH}$ per turn (doubled per glucose).

C4 Plants

Plants adapted to hot and dry environments (e.g., sugarcane, corn) that can close stomata to save water while maintaining active photosynthesis.

CAM Plants

Plants (e.g., pineapple, cacti) that conserve water in hot, dry environments by opening stomata exclusively at night to capture carbon dioxide.

Glycogenolysis

The breakdown (hydrolysis) of stored glycogen in the liver into glucose to supply blood sugar.

Myoglobin

An iron-containing protein stored in muscle tissues that binds oxygen, providing a dark red color to high-speed or active muscle fibers.