BIOL 100 Lecture Flashcards: Vocabulary from Properties of Life to Nucleic Acids

Vocabulary flashcards covering core terms from the notes: life, cellular biology, macromolecules, genetics, cell cycle, and basic biochemistry.

Life

The condition distinguishing living from nonliving matter, characterized by organized structure, response to stimuli, growth, reproduction, adaptation, metabolism, and homeostasis.

Properties of life

Key traits shared by living things: order, sensitivity, reproduction, adaptation, growth and development, regulation, homeostasis, and energy processing.

Order

Highly organized internal structures and systems, often at the cellular level.

Sensitivity (response to stimuli)

Ability of organisms to detect and respond to environmental changes.

Reproduction

Process by which organisms produce offspring and pass on genetic information.

Adaptation

Inherited traits that enhance an organism’s fitness in a given environment.

Growth and development

Increase in size and maturation guided by genetic instructions.

Regulation

Coordination of internal processes to maintain stable functioning.

Homeostasis

Maintenance of internal conditions within narrow limits despite external changes.

Energy processing

Acquisition and use of energy for metabolic activities; may involve photosynthesis or consumption of nutrients.

Cell

The basic unit of life; neurons, bacteria, and plant/animal cells alike; fundamental unit of structure and function.

Prokaryote

A simple cell type without a nucleus or membrane-bound organelles; e.g., Bacteria and Archaea.

Eukaryote

A cell type with a true nucleus and membrane-bound organelles; plants, animals, fungi, and protists.

Organelles

Membrane-bound compartments within a cell that perform specific functions.

Nucleus

Membrane-bound organelle that contains the cell’s DNA and regulates gene expression.

Mitochondria

Powerhouses of the cell; generate ATP via cellular respiration; contain own DNA and ribosomes.

Chloroplasts

Organelles that carry out photosynthesis in plants and algae; contain chlorophyll and own DNA.

Ribosome

Molecular machines that synthesize proteins; can be free-floating or attached to the endoplasmic reticulum.

Endoplasmic Reticulum

Network of membranous tubules; rough ER synthesizes proteins, smooth ER synthesizes lipids.

Golgi apparatus

Stacks of flattened membranes that modify, sort, and package proteins and lipids for transport.

Lysosome

Organelle with digestive enzymes that break down waste materials and cellular debris.

Peroxisome

Organelle that carries out oxidation reactions; detoxifies poisons; contains enzymes like catalase.

Cytoskeleton

Network of protein fibers (microfilaments, intermediate filaments, microtubules) that provide shape, support, and movement.

Vesicle

Small membrane-bound sac used for transport within and out of the cell.

Vacuole

Large membrane-bound storage sac; central vacuole in plants maintains turgor pressure.

Plasma membrane

Phospholipid bilayer that encloses the cell; regulates passage of substances; fluid mosaic model.

Diffusion

Passive movement of molecules from higher to lower concentration across a membrane or within a space.

Osmosis

Diffusion of water across a semipermeable membrane.

Facilitated diffusion

Diffusion of substances across membranes via transport proteins; requires no direct energy input.

Active transport

Movement of substances across membranes against their concentration gradient; requires energy.

Sodium-potassium pump

Primary active transport that moves Na+ out and K+ in to maintain ion gradients.

Endocytosis

Process of taking material into a cell by vesicle formation from the plasma membrane.

Phagocytosis

Endocytosis of large particles or whole cells ('cell eating').

Pinocytosis

Endocytosis of fluids and dissolved solutes ('cell drinking').

Receptor-mediated endocytosis

Endocytosis initiated by binding of ligands to specific cell-surface receptors.

Exocytosis

Process of exporting substances from the cell via vesicle fusion with the plasma membrane.

Enzyme

Protein catalyst that speeds up chemical reactions by lowering activation energy.

Substrate

Reactant molecule(s) that bind(s) to an enzyme at the active site.

Active site

Region of an enzyme where the substrate binds and the reaction occurs.

Induced fit

Model in which enzyme and substrate reshape slightly to achieve optimal binding.

Competitive inhibition

Inhibitor competes with the substrate for binding to the enzyme’s active site.

Noncompetitive inhibition

Inhibitor binds to a site other than the active site, changing enzyme shape and activity.

Cofactor

Inorganic ion that assists enzyme activity.

Coenzyme

Organic molecule (often vitamin-derived) that assists enzyme activity.

ATP

Adenosine triphosphate; primary energy currency of the cell.

DNA

Deoxyribonucleic acid; double-stranded genetic material carrying hereditary information.

RNA

Ribonucleic acid; single-stranded molecule involved in protein synthesis and regulation.

Nucleotide

Monomer of nucleic acids; composed of a sugar, a phosphate group, and a nitrogenous base.

Adenine

Purine base; pairs with Thymine in DNA and with Uracil in RNA.

Cytosine

Pyrimidine base; pairs with Guanine.

Guanine

Purine base; pairs with Cytosine.

Thymine

Pyrimidine base in DNA; pairs with Adenine.

Uracil

Pyrimidine base in RNA; replaces Thymine and pairs with Adenine.

Central Dogma

Flow of genetic information: DNA is transcribed into RNA, which is translated into protein.

DNA double helix

Two DNA strands wound around each other; sugar-phosphate backbone with bases inside; held by hydrogen bonds.

Base pairing

Specific hydrogen-bonded pairs: A with T (or U in RNA), C with G.

Genome

Complete set of genetic material present in an organism or cell.

Chromosome

DNA-protein complex; carries many genes; humans have 46 in somatic cells.

Gene

Functional unit of inheritance that codes for a protein or RNA product.

Locus

Specific location of a gene on a chromosome.

Diploid

Having two complete sets of chromosomes (2n); most human somatic cells are diploid.

Haploid

Having one set of chromosomes (n); sex cells are haploid.

Binomial nomenclature

Two-part naming system for species: Genus species (italics; genus capitalized, species lowercase).