Unit 1: Introduction & The Cell Vocabulary

Vocabulary flashcards covering anatomy, physiology, levels of organization, organ systems, homeostasis, basic chemistry, biological macromolecules, cell structure, membrane transport, protein synthesis, and the cell cycle based on Unit 1 notes.

Anatomy

The study of the structures of the body, including what they are made of and where they are located.

Gross Anatomy

The study of anatomical features visible with the naked eye.

Microscopic Anatomy

The study of anatomical structures that cannot be seen without magnification.

Cytology

The microscopic study of cells.

Histology

The microscopic study of tissues.

Physiology

The study of the individual and cooperative functions of anatomical structures.

Pathophysiology

The study of disease, also referred to as pathology.

Anatomical Position

The standard reference position for anatomical location terms, defined as standing upright with feet slightly apart, hands at the sides, palms facing forward, and thumbs pointing away from the body.

Supine

Refers to lying face up.

Prone

Refers to lying face down.

Atom

The smallest unit of matter, consisting of protons, neutrons, and electrons.

Molecule

A structure formed when two or more atoms are held together by chemical bonds.

Compound

A substance containing atoms of different elements chemically combined together in a fixed ratio, resulting in distinct properties from its component elements.

Cell

The smallest living unit of an organism, formed when molecules combine to form functional organelles.

Tissue

A community of similar cells working together to perform a specific function.

Organ

A body structure composed of two or more different tissues working together to perform specific functions.

Organ System

A group of organs working closely together to perform the functions of a body system.

Organism

The highest level of biological organization, in which many organ systems work harmoniously together to maintain an independent living entity.

Integumentary System

The organ system comprising the skin, hair, sweat glands, and nails that protects against environmental hazards, helps regulate body temperature, and provides sensory information.

Skeletal System

The organ system consisting of bones, cartilages, ligaments, and bone marrow that supports and protects tissues, stores minerals, and forms blood cells.

Muscular System

The organ system composed of skeletal muscles and associated tendons that enables movement, provides support, and maintains body temperature by generating heat.

Nervous System

The organ system containing the brain, spinal cord, peripheral nerves, and sense organs that detects stimuli, processes sensory information, and coordinates bodily responses.

Endocrine System

The organ system including glands such as the pituitary, thyroid, adrenal, pancreas, and gonads that secretes hormones to regulate long-term developmental and metabolic processes.

Cardiovascular System

The organ system composed of the heart, blood, and blood vessels that delivers oxygen, water, nutrients, and hormones to tissues while removing waste products and equalizing body temperature.

Lymphatic System

The organ system comprising the spleen, thymus, lymphatic vessels, lymph nodes, and tonsils that defends against infection and returns fluid to the bloodstream.

Respiratory System

The organ system containing the nasal passages, trachea, bronchi, and lungs that delivers oxygen to the blood, removes carbon dioxide, and produces sound.

Digestive System

The organ system including the mouth, esophagus, stomach, intestines, liver, gallbladder, and pancreas that processes food, absorbs nutrients, and eliminates undigested wastes.

Urinary System

The organ system consisting of the kidneys, ureters, urinary bladder, and urethra that excretes waste products from the blood, regulates blood pH and ion levels, and controls water balance.

Reproductive System

The organ system responsible for producing sex cells and sex hormones; in females, it also supports embryonic development and provides milk for infants.

Homeostasis

The tendency of physiological systems to maintain stable internal conditions such as body temperature, blood pressure, and pH.

Receptor

A component of a feedback loop that senses and detects changes in a regulated variable.

Control Center

A component of a feedback loop that integrates sensory information, compares it against a reference set point, and signals effectors.

Effector

A component of a feedback loop that makes adjustments to restore or alter the variable.

Negative Feedback Loop

A corrective homeostatic mechanism in which the effector action directly opposes a variation from normal limits to bring the variable back to its desired range.

Positive Feedback Loop

A homeostatic mechanism in which an initial stimulus produces a response that reinforces and amplifies the stimulus.

Proton

A subatomic particle located in the nucleus with a positive charge and a mass of 1 mass unit.

Neutron

A subatomic particle located in the nucleus with a neutral charge and a mass of 1 mass unit.

Electron

A subatomic particle located in the electron cloud with a negative charge and very low mass.

Atomic Number

The number of protons in an atom, which uniquely determines its chemical element.

Valence Shell

The outer electron shell of an atom, whose number of electrons dictates chemical properties and bonding behavior.

Element

A pure substance composed entirely of atoms of one kind with the same atomic number.

Ion

An atom that carries an electrical charge due to an unequal number of protons and electrons.

Anion

A negatively charged ion that has gained electrons.

Cation

A positively charged ion that has lost electrons.

Ionic Bond

A chemical bond resulting from the electrical attraction between ions of opposite charges.

Covalent Bond

A strong chemical bond formed when atoms share pairs of electrons.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms, resulting in no regional charge.

Polar Covalent Bond

A covalent bond in which electrons are shared unequally between atoms, creating partial positive and negative poles on the molecule.

Hydrogen Bond

A weak electrical attraction between a weakly positive hydrogen atom in a polar molecule and an electronegative atom of another molecule.

Synthesis Reaction

An anabolic chemical reaction ($\text{A} + \text{B} \rightarrow \text{AB}$) in which two or more components bond to form a larger molecule, storing energy in the bond.

Decomposition Reaction

A catabolic chemical reaction ($\text{AB} \rightarrow \text{A} + \text{B}$) that breaks down a larger molecule into smaller constituent parts, releasing energy.

Exchange Reaction

A chemical reaction ($\text{A} + \text{BC} \rightarrow \text{AB} + \text{C}$) involving both synthesis and decomposition, where bonds are broken and new bonds are formed.

Metabolism

The sum of all chemical reactions occurring within the human body.

Catabolism

The metabolic breakdown of complex molecules into simpler ones, accompanied by energy release.

Anabolism

The metabolic synthesis of complex molecules from simpler ones, requiring energy input.

Inorganic Compound

A substance that does not contain both carbon and hydrogen.

Organic Compound

A substance that contains both carbon and hydrogen.

Salt

An inorganic substance that dissociates in water into ions other than $\text{H}^+$ or $\text{OH}^-$.

Electrolyte

An ion in solution capable of conducting an electrical current.

Acid

A substance that releases hydrogen ions ($\text{H}^+$) in solution; acts as a proton donor.

Base

A substance that releases hydroxyl ions ($\text{OH}^-$) in solution; acts as a proton acceptor.

pH

A logarithmic measure of the hydrogen ion ($\text{H}^+$) concentration in a solution.

Buffer System

A mechanism that stabilizes solution pH by binding or releasing $\text{H}^+$ ions in response to chemical fluctuations.

Carbohydrate

An organic molecule composed of carbon, hydrogen, and oxygen, typically present in a generic ratio of $(\text{CH}_2\text{O})_n$.

Monosaccharide

A simple sugar unit that serves as the building block for complex carbohydrates.

Glucose

The primary metabolic fuel monosaccharide in the human body ($\text{C}_6\text{H}_{12}\text{O}_6$).

Fructose

A simple monosaccharide known as fruit sugar, found naturally in fruits, honey, and vegetables.

Galactose

A monosaccharide with the chemical formula $\text{C}_6\text{H}_{12}\text{O}_6$, arranged in a different structural configuration than glucose.

Ribose

A pentose sugar that forms the structural backbone of RNA.

Deoxyribose

A pentose sugar that forms the structural backbone of DNA, differing from ribose by the absence of one oxygen atom.

Disaccharide

A carbohydrate composed of two monosaccharides linked by a glycosidic bond formed via dehydration synthesis.

Sucrose

A disaccharide table sugar formed by bonding glucose and fructose.

Maltose

A disaccharide malt sugar formed by bonding two glucose molecules.

Lactose

A disaccharide milk sugar formed by bonding galactose and glucose.

Polysaccharide

A complex carbohydrate composed of long polymer chains of monosaccharides.

Glycogen

A highly branched glucose polymer stored in animal liver and muscle tissues.

Starch

A digestible plant glucose polymer occurring as linear amylose or branched amylopectin.

Cellulose

An indigestible structural plant glucose polymer that provides dietary fiber.

Lipids

A class of nonpolar, hydrophobic organic compounds composed mostly of hydrocarbons.

Triglycerides

Dietary and tissue lipids consisting of a glycerol backbone attached to three fatty acid chains.

Saturated Fat

A triglyceride containing only single covalent carbon bonds that is fully saturated with hydrogen and solid at room temperature.

Unsaturated Fat

A triglyceride containing one or more double or triple carbon bonds that is liquid at room temperature.

Phospholipid

An amphipathic lipid consisting of a hydrophilic, polar phosphate head and two hydrophobic, nonpolar fatty acid tails.

Steroid

A lipid composed of four interlocking hydrocarbon rings used in cellular messaging and membrane structure.

Cholesterol

The most common body steroid, serving as a structural component of cell membranes and a synthesis precursor for bile acids and steroid hormones.

Protein

An organic macromolecule composed of amino acid chains linked by peptide bonds, whose 3D structure determines its biological function.

Amino Acid

A protein monomer featuring an amino group, a carboxyl group, a central carbon, and one of 20 distinct side chains (R groups).

Peptide Bond

A covalent bond joining amino acids together in a polypeptide chain formed through dehydration synthesis.

Primary Structure

The linear sequence of amino acids linked together in a polypeptide chain.

Secondary Structure

Localized regular spatial folding patterns in a polypeptide chain, such as alpha-helices or beta-pleated sheets.

Tertiary Structure

The complete three-dimensional folded shape of a single polypeptide chain.

Quaternary Structure

The complex 3D protein structure formed when two or more distinct polypeptide subunits combine.

Nucleic Acids

Macromolecules composed of nucleotide subunits (phosphate, pentose sugar, and nitrogenous base) that handle genetic storage and energy transfer.

DNA

Deoxyribonucleic acid; a double-stranded nucleic acid stored in the nucleus that encodes genetic instructions using adenine, thymine, cytosine, and guanine.

RNA

Ribonucleic acid; a single-stranded nucleic acid operating in the cytoplasm to copy DNA instructions and direct protein synthesis using adenine, uracil, cytosine, and guanine.

ATP

Adenosine triphosphate; a high-energy nucleotide containing ribose, adenine, and three phosphate groups that functions as cellular energy currency.

Cell Theory

The foundational concept stating that cells are the basic structural and functional units of life, arise only from preexisting cells, and maintain homeostasis.

Germ Cells

Reproductive gamete cells (sperm or egg) that possess a half set of chromosomes.

Somatic Cells

All non-reproductive body cells containing a full set of chromosomes.

Intracellular Space

The internal fluid compartment located entirely inside the cell membrane.