Introduction to Biology and Cellular Foundations

Flashcards covering key vocabulary concepts from Chapter 1 to Chapter 5 lectures, including scientific inquiry, macromolecule biochemistry, organelle structures, and membrane transport.

Discovery Science

A scientific approach that seeks natural causes for natural phenomena by observing and measuring nature, limiting study to observable structures and processes.

Hypothesis-Driven Science

A scientific approach aimed at explaining nature through observations, questions, hypotheses, predictions, experiments, and revisions.

Hypothesis

A tentative answer or proposed explanation for a set of observations that leads to testable predictions.

Theory

A comprehensive explanation with explanatory power and evidence that ties together many seemingly unrelated observations and is general enough to derive new hypotheses.

Seven Processes of Life

The seven fundamental traits describing life: order, regulation, growth & development, energy processing, response to environment, reproduction, and evolution.

Species

Organisms that live in the same time and place and breed with one another in nature to produce healthy offspring.

Taxonomy

The scientific discipline that classifies species and arranges them into categories from general to specific.

Three Domains of Life

The three overarching categories of living organisms: Bacteria, Archaea, and Eukarya.

Eukarya

A domain composed of organisms made of eukaryotic cells, encompassing Kingdom Animalia, Kingdom Plantae, Kingdom Fungi, and Protists.

Natural Selection

An evolutionary mechanism where organisms with traits better suited to their environment are more likely to survive and reproduce, passing on advantageous adaptations.

Artificial Selection

The process by which humans deliberately choose and alter genetic traits to select which species survive and reproduce.

Emergent Properties

Specific arrangements and interactions that arise as complexity increases within a complex system.

Organic Compounds

Carbon-based molecules where carbon can form four covalent bonds due to its four free valence electrons.

Five Functional Groups

Key chemical groups found on biological molecules: Hydroxyl, Carbonyl, Carboxyl, Amino, and Phosphate.

Macromolecule

Large body-building biological molecules including proteins, nucleic acids, carbohydrates, and lipids.

Dehydration Reaction

A chemical reaction that builds a polymer chain by removing an $\text{-OH}$ group from one monomer and an $\text{-H}$ group from another, requiring energy.

Hydrolysis

A chemical process that breaks down polymers into individual monomers by adding water along with specific enzymes, releasing energy.

Monosaccharides

Simple sugar monomers of carbohydrates classified by carbon count, such as triose (3 carbons), pentose (5 carbons), and hexose (6 carbons).

Isomers

Molecules that share the exact same chemical formula but have different structural arrangements, such as glucose, fructose, and galactose.

Disaccharides

Sugars formed by joining two monosaccharides through dehydration synthesis, including sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).

Polysaccharides

Complex carbohydrates made of long chains of sugar monomers, such as starch, glycogen, and cellulose.

Cellulose

A structural polysaccharide made of straight glucose chains linked by hydrogen bonds that forms tough plant cell walls and is resistant to breakdown by mammals.

Lipids

Large, nonpolar, hydrophobic molecules containing few oxygen atoms that dissolve in nonpolar substances; includes true fats, phospholipids, and steroids.

Triglyceride

A fat molecule constructed from one glycerol molecule joined to three fatty acid chains via dehydration reactions.

Saturated Fat

A fat molecule lacking carbon-carbon double bonds, typically derived from animals, that remains solid at room temperature.

Unsaturated Fat

A plant-derived fat containing one or more double-bonded carbon atoms that remains liquid at room temperature.

Phospholipids

Complex molecules consisting of two fatty acid tails and one phosphate group attached to glycerol, forming the primary component of cellular membranes.

Steroids

Lipids characterized by a carbon backbone containing 4 fused rings of $\text{CH}_3$; includes cholesterol, which serves as a precursor for estrogen and testosterone.

Proteins

Biological polymers made of amino acid monomers linked by peptide bonds that perform diverse tasks such as structure, storage, contraction, transport, and enzymatic activity.

Amino Acid Structure

A central carbon atom attached to four single-covalent components: an amino group ($\text{NH}_3$), a carboxyl group ($\text{COOH}$), a hydrogen atom, and a variable side chain.

Prions

Misfolded proteins in the brain that induce normal variants to fold incorrectly, leading to prion clumps, cellular death, memory loss, confusion, and loss of coordination.

Nucleotides

Monomers of nucleic acids composed of a 5-carbon pentose sugar (deoxyribose or ribose), a phosphate group, and a nitrogenous base.

Nitrogenous Bases of DNA

The four specific chemical bases in DNA nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

RNA

A single-stranded nucleic acid containing ribose sugar and the nitrogenous base uracil (U) instead of thymine, existing as mRNA, rRNA, and tRNA.

Cell Theory

The unifying biological principle that all living organisms are composed of cells and that all modern cells arise from pre-existing cells through cell division.

Prokaryotic Cells

Older, smaller, and simple cells that evolved $3.5 \times 10^9$ years ago, lacking membrane-bound organelles and a true nucleus, such as Bacteria and Archaea.

Eukaryotic Cells

Complex cells that evolved $2.1 \times 10^9$ years ago, characterized by membrane-bound organelles and a true double-membraned nucleus containing linear chromosomes.

Nucleoid

The non-membrane-enclosed region in a prokaryotic cell where its single circular chromosome of DNA is coiled.

Cytosol

The thick, jelly-like fluid interior of a cell in which cellular organelles and components are suspended.

Plasma Membrane

A fluid mosaic structure made of a phospholipid bilayer with embedded proteins that regulates molecular traffic in and out of the cell.

Nucleolus

A specialized region within the nucleus where ribosome components are produced before exiting through nuclear pores.

Chromatin

Long DNA molecules packaged alongside proteins stored within the nucleus that condense into individual chromosomes.

Endomembrane System

A network of cellular organelles linked physically or by vesicles, consisting of the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles.

Rough Endoplasmic Reticulum

A portion of the ER studded with external ribosomes that manufactures membranes and chemically alters proteins for transport via vesicles.

Smooth Endoplasmic Reticulum

A ribosome-free portion of the ER that synthesizes lipids and steroids and contains enzymes that aid in drug and toxin detoxification in the liver.

Golgi Apparatus

An organelle consisting of stacked membrane plates that receives, modifies, stores, and routes chemical products from the ER.

Lysosome

A membrane-enclosed sac of digestive enzymes found in animal cells used to break down proteins, fats, polysaccharides, nucleic acids, and worn-out organelles.

Central Vacuole

A large plant organelle taking up over half the cell's volume that stores organic nutrients, absorbs water to maintain pressure, and holds pigments or defensive toxins.

Chloroplast

A photosynthetic organelle with a double-membrane envelope containing stroma, thylakoids, and grana that converts light energy into ATP and chemical energy.

Mitochondria

Eukaryotic organelles with inner cristae and a matrix where cellular respiration occurs to convert energy from food into ATP.

Endosymbiosis Theory

The evolutionary concept that mitochondria and chloroplasts originated from ancient prokaryotes that lived symbiotically inside larger host eukaryotic cells.

Cytoskeleton

A dynamic network of protein fibers—microtubules, intermediate filaments, and microfilaments—that maintains cell shape, anchors organelles, and enables movement.

Cilia and Flagella

Microtubule-based cell extensions; flagella move in a whip-like motion to propel cells, while shorter, more numerous cilia move in a back-and-forth motion.

Diffusion

The passive movement of molecules down their concentration gradient from an area of higher concentration to lower concentration without energy input.

Osmosis

The passive movement or diffusion of water across a selectively permeable membrane toward a hypertonic solution (higher solute concentration).

Hypertonic Solution

A solution with a higher concentration of solute relative to another solution, causing animal cells to shrivel and plant cells to undergo plasmolysis.

Hypotonic Solution

A solution with a lower concentration of solute, causing animal cells to take in water and lyse, but creating healthy turgid conditions in plant cells.

Facilitated Diffusion

A form of passive transport where specific membrane carrier proteins assist molecules in moving down their concentration gradient without consuming ATP.

Active Transport

The energy-requiring process (using ATP) where transport proteins pump molecules across a membrane up or against their concentration gradient.

Endocytosis

The active process of taking materials into a cell by enclosing them in vesicles formed from the plasma membrane; includes phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Exocytosis

The transport process where intracellular vesicles containing molecules fuse with the plasma membrane to export materials out of the cell.