Biology 12: Cell Structure, Cell Compounds, and Biological Molecules

Comprehensive vocabulary flashcards covering cell structure, cell compounds, biological macromolecules, and protein organization for Biology 12.

Dissection Microscope

An optical microscope designed for low-magnification observation of biological specimens and safe dissection techniques.

Compound Microscope

An optical instrument using multiple lenses to magnify and resolve detailed cellular structures from visual representations and specimens.

Cell Membrane

A cellular boundary structure that regulates the passage of substances, facilitates compartmentalization, and moves materials into and out of the cell.

Mitochondria

Cellular organelles composed of cristae and a matrix that serve as the site for cellular respiration to produce energy.

Cristae

The internal folds of the inner mitochondrial membrane that expand the surface area for cellular respiration.

Mitochondrial Matrix

The internal fluid-filled space enclosed by the inner mitochondrial membrane.

Rough Endoplasmic Reticulum

An organelle studded with ribosomes involved in compartmentalizing the cell, synthesizing proteins, and moving materials throughout the cell.

Smooth Endoplasmic Reticulum

A membranous organelle devoid of ribosomes that functions in lipid synthesis, cellular compartmentalization, and transporting materials.

Ribosomes (Polysomes)

Cellular structures, occurring individually or in clusters called polysomes, responsible for translating genetic messages into proteins.

Golgi Bodies

A stack of membranous sacs that functions to modify, sort, package, compartmentalize, and transport materials via vesicles.

Vesicles

Small, membrane-bound transport spheres that move materials between cellular compartments and to the cell membrane.

Vacuoles

Membrane-bound storage organelles within cells used to store water, nutrients, or waste products.

Lysosomes

Specialized vesicles containing digestive enzymes used to break down wastes, cellular debris, and foreign substances.

Nucleus

The central control organelle of a eukaryotic cell, containing the nuclear envelope, nuclear pores, nucleolus, chromatin, and chromosomes.

Nuclear Envelope

The double-membrane boundary surrounding the nucleus, perforated by nuclear pores to regulate molecular transport.

Nuclear Pore

Protein-lined openings in the nuclear envelope that allow controlled movement of molecules between the nucleus and the cytoplasm.

Nucleolus

A dense region inside the nucleus responsible for the production and assembly of ribosomal components.

Chromatin

The diffuse, uncoiled form of DNA and associated proteins found in the nucleus during interphase.

Chromosomes

Distinct, tightly coiled thread-like structures of DNA and proteins that carry hereditary genetic information.

Cell Wall

A rigid, protective outer layer external to the cell membrane found in plants and certain other organisms.

Chloroplast

A specialized organelle in plant cells that captures light energy to produce organic molecules through photosynthesis.

Cytoskeleton

An internal structural network of protein filaments and tubules that maintains cell shape, anchors organelles, and aids in motility.

Cytoplasm

The semifluid material bounded by the cell membrane that suspends organelles and serves as a site for cellular chemical reactions.

Balanced Chemical Equation for Cellular Respiration

The stoichiometry representing the breakdown of glucose with oxygen into carbon dioxide, water, and energy: $\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{energy}$.

Hydrogen Bonding (in Water)

Weak electrostatic attractions between the partial positive charge of a hydrogen atom in one polar water molecule and the partial negative charge of an oxygen atom in another.

Water as a Solvent

The capacity of water to dissolve polar and ionic substances, providing a biological medium for chemical reactions and molecular transport.

Water as a Temperature Regulator

The property of water to resist rapid temperature fluctuations due to its high heat capacity, maintaining thermal homeostasis in biological systems.

Water as a Lubricant

The role of water in reducing friction between joints, internal tissues, and moving biological surfaces in the human body.

Acids, Bases, and Buffers

Acids release hydrogen ions; bases accept hydrogen ions or produce hydroxide ions; buffers stabilize and maintain constant pH in biological systems of the human body.

Dehydration Synthesis

A chemical reaction that covalently links organic monomers into polymers through the removal of a water molecule.

Hydrolysis

A cleavage reaction that breaks down organic polymers into their constituent monomers by adding a molecule of water.

Carbohydrate Empirical Formula

The standard proportional formula for carbohydrates: $\text{C}_n\text{H}_{2n}\text{O}_n$.

Monosaccharide

The simplest single-unit monomer of carbohydrates, such as glucose or ribose, that serves as cellular fuel or structural building blocks.

Disaccharide

A carbohydrate composed of two monosaccharide units joined together by a covalent bond, such as maltose.

Polysaccharide

A complex polymer composed of long chains of repeating monosaccharide subunits, such as starch, glycogen, and cellulose.

Starch

A plant storage polysaccharide composed of glucose subunits, characterized by moderate branching and specific glycosidic bonding.

Glycogen

A highly branched animal storage polysaccharide made of glucose monomers, located mainly in the liver and muscles for rapid energy release.

Cellulose

An unbranched structural plant polysaccharide with specific alternating bond orientations that provides rigidity to plant cell walls.

Neutral Fat

A lipid composed of one glycerol molecule bonded to three fatty acids, located in adipose tissue for long-term energy storage, insulation, and organ protection.

Saturated Fatty Acid

A fatty acid hydrocarbon chain containing only single covalent carbon-carbon bonds, maximizing the number of bonded hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid whose hydrocarbon chain contains one or more double bonds between carbon atoms, resulting in kinks in the molecular structure.

Phospholipid

A membrane lipid consisting of a glycerol molecule bonded to a phosphate group and two fatty acid tails, forming the bilayer of cellular membranes.

Steroids

Lipid molecules composed of four interconnected carbon rings, serving as hormones and structural membrane components in the human body.

Generalized Amino Acid

The monomer of proteins, consisting of a central carbon atom bonded to an amine group, an acid (carboxyl) group, a hydrogen atom, and a variable R-group.

Peptide Bond

The covalent bond that joins the carboxyl group of one amino acid to the amine group of another within dipeptides and polypeptides.

Primary Protein Structure

The linear sequence of amino acids in a polypeptide chain linked together by covalent peptide bonds.

Secondary Protein Structure

The localized folding of a polypeptide chain into an alpha helix or beta pleated sheet, stabilized by hydrogen bonds along the backbone.

Tertiary Protein Structure

The complex three-dimensional folding of a single polypeptide chain, determined by interactions and bonding among various R-groups.

Quaternary Protein Structure

The higher-order structural organization formed by the aggregation of two or more polypeptide chains, exemplified by hemoglobin.

Hemoglobin

A quaternary transport protein found in red blood cells that binds and transports oxygen throughout the body.

Deoxyribonucleic Acid (DNA)

A nucleic acid polymer composed of deoxyribose-containing nucleotides that encodes and stores hereditary genetic information.

Ribonucleic Acid (RNA)

A nucleic acid polymer containing ribose sugar that functions in transcribing and translating genetic information into proteins.

Adenosine Triphosphate (ATP)

The universal 'energy currency' of cells, composed of ribose, adenine, and three phosphate groups, which releases usable energy when high-energy phosphate bonds are hydrolyzed.