BI 112: Cell Biology for Health Occupations - Comprehensive Review

Vocabulary practice flashcards covering human anatomy and physiology, chemical foundations, bonding, water properties, thermodynamics, enzymatic kinetics, stoichiometry, solutions, acid-base homeostasis, and biological macromolecules.

Gross Anatomy

The study of the larger structures of the body visible without the aid of magnification, also referred to as macroscopic anatomy.

Microscopic Anatomy

The study of body structures that can be observed only with the use of a microscope or other magnification devices, including cytology and histology.

Regional Anatomy

The anatomical approach that studies the interrelationships of all the structures within a specific body region, such as the abdomen.

Systemic Anatomy

The study of the structures that make up a discrete body system, which is a group of structures that work together to perform a unique body function.

Human Physiology

The scientific study of the chemistry and physics of the structures of the body and the ways in which they work together to support the functions of life.

Homeostasis

The state of steady internal conditions maintained by living things despite changes in external conditions.

Levels of Structural Organization

The hierarchy of increasing complexity in the human body: chemical, cellular, tissue, organ, organ system, and organismal levels.

Cell

The smallest independently functioning structural and functional unit of a living organism, enclosed by flexible membranes containing cytoplasm and organelles.

Tissue

A community of many similar cells (or sometimes a few related types) that work together to perform a specific function.

Organ

An anatomically distinct structure of the body composed of two or more tissue types that performs one or more specific physiological functions.

Organ System

A group of organs that work closely together to perform major functions or meet the physiological needs of the body; the human body contains 11 such systems.

Negative Feedback Loop

A homeostatic control mechanism consisting of a stimulus, sensor, control center, and effector that maintains body parameters within their normal range by reversing a deviation from the set point.

Set Point

The ideal physiological value around which the normal range fluctuates, such as approximately $37^\text{o}\text{C}$ ($98.6^\text{o}\text{F}$) for human body temperature.

Sensor

A receptor in a feedback system that monitors a physiological value and transmits that information to the control center.

Control Center

The component of a feedback system that receives input from a sensor, compares the value to its normal range/set point, and signals an effector if deviation occurs.

Effector

The component in a feedback system that receives output from the control center and causes a physiological change to respond to a stimulus.

Positive Feedback Loop

A physiological mechanism that intensifies or amplifies a change in the body's condition rather than reversing it, continuing until a definite end point is reached.

Platelet Plug Formation

A positive feedback process initiated by a break in a blood vessel wall where adhering platelets release chemicals that attract additional platelets until a seal is fully formed.

Homeostatic Imbalance

A disturbance in the body's steady internal state that increases disease risk, accelerates aging-related decline, or leads to abnormal conditions such as type 2 diabetes or heat stroke.

Element

A pure substance that cannot be created or broken down by ordinary chemical means; 92 occur naturally, and four (oxygen, carbon, hydrogen, nitrogen) make up $96\%$ of the human body mass.

Atom

The smallest quantity of an element that retains the unique physical and chemical properties of that element.

Subatomic Particles

The fundamental units of atoms: positively charged protons ($1\,\text{amu}$), uncharged neutrons ($1\,\text{amu}$), and negatively charged electrons ($0\,\text{amu}$, roughly $1/2000\text{th}$ the mass of a proton).

Atomic Number

The number of protons found in the nucleus of an atom, which uniquely identifies the element and corresponds to the number of electrons in an electrically neutral atom.

Mass Number

The total sum of the number of protons and neutrons located within the nucleus of an atom.

Isotopes

Different structural forms of the same element that possess identical numbers of protons but differing numbers of neutrons.

Radioisotope

An unstable isotope whose nucleus spontaneously decays, emitting subatomic particles and electromagnetic radiation; characterized by a specific half-life ($t_{1/2}$).

Radioembolization

A minimally invasive interventional radiology procedure in which tiny radioactive seeds are inserted directly into blood vessels supplying liver tumors to destroy tumor tissue.

Electron Shells

Concentric energy levels surrounding an atomic nucleus where electrons reside; shell 1 holds up to $2$ electrons, shell 2 holds up to $8$, and shell 3 holds up to $18$.

Octet Rule

The chemical principle stating that atoms are most stable when their outermost valence shell contains eight electrons, driving them to gain, lose, or share electrons.

Ion

An atom or molecule that has acquired an electrical charge due to the loss or gain of one or more valence shell electrons.

Cation

A positively charged ion formed when an atom donates or loses one or more valence electrons, such as $\text{Na}^+$ or $\text{Ca}^{2+}$.

Anion

A negatively charged ion formed when an atom gains one or more valence electrons, such as $\text{Cl}^-$ or $\text{F}^-$.

Ionic Bond

A chemical bond formed by the ongoing electrostatic attraction between oppositely charged cations and anions following electron transfer.

Electrolyte

A substance that dissociates into ions when dissolved in water, producing a solution capable of conducting an electrical current.

Covalent Bond

A strong chemical bond formed when two atoms share one, two, or three pairs of valence electrons to mutually fill their outer electron shells.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms with identical or very similar electronegativities, resulting in balanced charge distribution.

Polar Covalent Bond

A covalent bond formed by the unequal sharing of electrons due to differing electronegativities, giving one atom a partial negative charge ($\delta^-$) and the other a partial positive charge ($\delta^+$).

Hydrogen Bond

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

High Heat Capacity of Water

The property of water requiring a relatively large amount of heat energy ($1\,\text{calorie}$ or $4.18\,\text{J/(g}\cdot^\text{o}\text{C)}$) to raise its temperature by $1^\text{o}\text{C}$, helping stabilize body temperature.

High Heat of Vaporization

The substantial amount of heat energy ($586\,\text{cal}$ or approximately $2400\,\text{J/g}$) required to transform liquid water into steam, which allows sweating to cool the body.

Cohesion

The intermolecular attraction between water molecules caused by hydrogen bonding, which creates surface tension at the liquid-gas interface.

Adhesion

The attraction of water molecules to other polar or charged surfaces, which drives capillary action in narrow tubes.

Hydrophobic Effect

The tendency of polar water molecules to hydrogen-bond with each other, excluding nonpolar substances and causing lipids to assemble into bilayers and proteins to fold.

Incompressibility of Water

The physical characteristic of liquid water wherein volume barely decreases under pressure, enabling fluids like cerebrospinal and synovial fluid to cushion organs and transmit force.

Solution

A clear, homogeneous mixture consisting of a solvent (the dissolving medium present in greatest volume) and one or more solutes distributed evenly at the molecular scale.

Colloid

A heterogeneous mixture containing solute particle clumps that are large enough to scatter light and appear cloudy or opaque, but do not settle out over time.

Suspension

A heterogeneous liquid mixture containing large, visible solute particles that temporarily suspend but settle out over time through sedimentation.

Sphere of Hydration

A shielding shell of oriented water molecules that surrounds dissolved ions, with partially negative oxygen atoms facing cations and partially positive hydrogen atoms facing anions.

Mole

A measurement unit indicating an amount of a substance equal to its gram molecular weight, containing Avogadro's number ($6.02 \times 10^{23}$) of particles.

Molarity ($M$)

A concentration unit defined as the number of moles of solute dissolved per liter of total solution ($\text{mol/L}$).

Equivalent (Eq)

A concentration unit representing one mole of electrical charge on an ion, used to measure clinical fluid electrolytes regardless of solute identity.

Mass-Volume Percent ($\%(m/v)$)

A concentration metric expressing the grams of solute dissolved per $100\,\text{mL}$ of solution, commonly used on clinical intravenous fluid labels.

Dilution Equation

The mathematical relationship $C_1 V_1 = C_2 V_2$ stating that the total amount of solute remains constant while solvent volume increases during dilution.

Acid

A substance that releases hydrogen ions ($\text{H}^+$) when dissolved in water, raising the solution's hydronium concentration.

Base

A substance that releases hydroxide ions ($\text{OH}^-$) in solution or directly accepts free hydrogen ions ($\text{H}^+$), reducing acidity and raising pH.

Salt

An ionic compound that, when dissolved in aqueous solution, dissociates into electrolytes other than $\text{H}^+$ or $\text{OH}^-$.

$$\text{pH}$$

The negative base-10 logarithm of hydrogen ion concentration in moles per liter ($\text{pH} = -\log_{10}[\text{H}^+]$), where each single unit represents a tenfold change in acidity.

Buffer

A chemical system composed of a weak acid and its conjugate base that resists changes in solution $\text{pH}$ by binding or releasing $\text{H}^+$.

Bicarbonate Buffer System

The primary physiological extracellular fluid buffer system governed by the reversible reaction $\text{CO}_2 + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3 \rightleftharpoons \text{H}^+ + \text{HCO}_3^-$, regulated by the lungs and kidneys.

Acidosis

A physiological condition in which blood $\text{pH}$ drops below the normal range of $7.35$, caused by respiratory retention of $\text{CO}_2$ or metabolic acid accumulation.

Alkalosis

A physiological disorder characterized by blood $\text{pH}$ rising above $7.45$, caused by hyperventilation-induced $\text{CO}_2$ loss or metabolic proton depletion.

Exergonic Reaction

A chemical reaction that results in a net release of free energy ($-\Delta G$), in which products possess less potential energy than reactants.

Endergonic Reaction

A non-spontaneous chemical reaction that requires an input of free energy ($+\Delta G$), yielding products that possess greater potential energy than reactants.

Energy Coupling

The biological process in which the free energy released by an exergonic reaction drives an endergonic reaction, commonly mediated by ATP hydrolysis.

Synthesis Reaction

An anabolic chemical reaction in which two or more smaller reactants bond together to produce a larger, more complex product ($\text{A} + \text{B} \rightarrow \text{AB}$).

Decomposition Reaction

A catabolic chemical reaction in which bonds within a larger reactant are broken to produce smaller molecules or individual atoms ($\text{AB} \rightarrow \text{A} + \text{B}$).

Exchange Reaction

A reaction involving both synthesis and decomposition, where bonds are simultaneously formed and broken to trade components between molecules ($\text{AB} + \text{CD} \rightarrow \text{AD} + \text{BC}$).

Redox Reaction

A coupled chemical process where oxidation (loss of electrons) by one substance occurs simultaneously with reduction (gain of electrons) by another.

Activation Energy

The threshold minimum amount of energy required to strain and break chemical bonds in reactants to initiate a chemical reaction.

Enzyme

A biological catalyst composed of protein (or RNA) that accelerates reaction rates by lowering activation energy without being altered or consumed in the process.

Enzyme Saturation

The condition occurring at high substrate concentrations where every enzyme active site is occupied, causing the reaction rate to plateau at its maximum velocity ($V_{\max}$).

Net Ionic Equation

A chemical equation from which spectator ions have been eliminated, detailing only the species directly participating in bond breaking or forming.

Dehydration Synthesis

A condensation reaction that covalently links monomers together into a polymer by removing a hydrogen atom from one monomer and a hydroxyl group from another, releasing a water molecule.

Hydrolysis

A cleavage reaction that breaks covalent bonds in a polymer by adding a water molecule, attaching a proton to one fragment and a hydroxyl group to the other.

Hydrocarbon Geometry

The three-dimensional spatial arrangement of carbon bonds: single carbon bonds form a tetrahedral geometry, double bonds form a rigid planar shape, and triple bonds form a linear configuration.

Structural Isomers

Molecules that share an identical chemical formula but differ in the covalent arrangement and connectivity of their constituent atoms.

Geometric Isomers

Molecules with the same covalent connectivity that differ in the spatial orientation of groups around a rigid double bond (cis with groups on the same side, trans on opposite sides).

Enantiomers

Molecules that share identical chemical composition and bond connections but are non-superimposable mirror images of each other, typically distinguished as D- and L-forms.

Functional Groups

Specific clusters of atoms attached to a carbon backbone (including hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl) that confer distinct chemical properties.

Monosaccharide

A monomeric simple sugar conforming to the general stoichiometric formula $(\text{CH}_2\text{O})_n$; classified as an aldose or ketose, and by carbon count as triose, pentose, or hexose.

Hexose Isomers

Monosaccharides containing six carbons ($\text{C}_6\text{H}_{12}\text{O}_6$) with differing functional group orientations, specifically glucose and galactose (aldoses) and fructose (a ketose).

Glycosidic Bond

A covalent linkage formed between the hydroxyl groups of two monosaccharide units via a dehydration reaction, classified as alpha (below the ring) or beta (above the ring).

Polysaccharide

A long chain polymer of monosaccharides joined by glycosidic bonds, serving as energy storage (starch, glycogen) or structural components (cellulose, chitin).

Triacylglycerol

A lipid molecule composed of a glycerol backbone linked by ester bonds to three fatty acid chains, serving as the body's primary long-term energy storage form.

Phospholipid

An amphipathic lipid composed of two hydrophobic fatty acid chains and a hydrophilic modified phosphate group attached to a glycerol or sphingosine backbone, forming cellular membrane bilayers.

Steroid

A class of nonpolar hydrophobic lipids characterized by a fused ring framework of four linked carbon rings, exemplified by cholesterol, cortisol, and sex hormones.

Cholesterol

The most abundant steroid in animal tissues, synthesized in the liver; acts as a structural component of the plasma membrane and as the precursor for steroid hormones, vitamin D, and bile salts.