Physiology Exam 1

Pathology

the study of disease, its causes, processes, development, and consequences.

Physiology

the scientific study of normal living functions within an organism, organ, tissue, or cell, focusing on how these parts work together to maintain life and respond to internal and external changes

Anatomy

the scientific study of the structure of living organisms and their parts

Circadian Rhythm

your body's internal, 24-hour clock that regulates your sleep-wake cycle, hormone release, body temperature, and other crucial functions

Effector

responding unit

Emergent properties

characteristics that arise from the interactions of simpler components within a complex system. Ex. organ→ organ system

Extracellular fluid

all body fluid located outside of cells, primarily composed of blood plasma and interstitial fluid

Intracellular membranes

the water and solutes (like potassium, phosphate, and proteins) contained inside the cell membranes

Homeostasis is a ___, not a static,

process

dynamic

receptor

detects change in some variable in internal environment

control center

processes information and directs an appropriate response

Response

what occurs from the output signal

Negative feedback

the response counteracts the stimulus, shutting off the loop

Positive feedback

the response reinforces the stimulus, sending the variable farther back from its set point

Mechanistic approach

describes the “how”, Oxygen binds to hemoglobin molecules contained in the red blood cells

Teleological approach

explains the “why”, because cells need oxygen and red blood cells bring it to them

Mass flow

the measure of the mass of a substance passing through a given point or cross-section per unit of time

Homeostasis

the automatic process by which living organisms maintain a stable internal environment, keeping variables like temperature, blood sugar, and fluid levels within a narrow, healthy range despite changes in the external environment

reflex control

is a more widespread, coordinated response involving long-distance signaling through the nervous and/or endocrine systems

local control

is a self-contained regulation within a specific tissue or cell, often using paracrine or autocrine signals

4 key themes in Physiology

Structure and Function Relationships, Energy needs, Information Flow, Homeostasis

Acid

A substance that donates hydrogen ions (H⁺) in solution, lowering pH

Amino acid

The building block of proteins, consisting of an amino group, carboxyl group, hydrogen atom, and variable R group attached to a central carbon

Amphipathic

A molecule that has both hydrophilic (water-loving) and hydrophobic (water-fearing) regions.

Base

A substance that accepts hydrogen ions (H⁺) in solution, raising pH

Carbohydrate

Organic molecule made of carbon, hydrogen, and oxygen (usually in a 1:2:1 ratio); includes sugars and starches used for energy and structure.

Cellulose

A polysaccharide made of glucose units that forms plant cell walls and provides structural support.

Covalent bond

A chemical bond formed when atoms share one or more pairs of electrons.

Denaturation

Loss of a protein’s shape (and function) due to heat, pH changes, or other stressors.

Disaccharide

A carbohydrate made of two monosaccharides linked by a covalent bond (e.g., sucrose, lactose).

Electronegativity

The tendency of an atom to attract electrons toward itself in a chemical bond

Fatty acid

A long hydrocarbon chain with a carboxyl group at one end; building blocks of many lipids.

Free radical

An unstable molecule with an unpaired electron that can damage cells.

Glucose

A monosaccharide (C₆H₁₂O₆) that is the primary energy source for cells.

Glycerol

A three-carbon molecule that forms the backbone of fats and phospholipids.

Glycogen

A polysaccharide made of glucose that serves as energy storage in animals.

Glycolipid

A lipid with one or more carbohydrate groups attached, important in cell recognition

Glycoprotein

A protein with carbohydrate groups attached, often found on cell membranes for signaling.

High energy electron

An electron that carries extra energy, often transferred in redox reactions or stored in molecules like NADH.

Hydrogen bond

A weak bond between a hydrogen atom (covalently bound to an electronegative atom) and another electronegative atom.

Hydrophilic

“Water-loving”; molecules that dissolve easily in water (polar or charged).

Hydrophobic

“Water-fearing”; molecules that do not dissolve in water (nonpolar)

Induced fit

Enzyme model where the active site changes shape slightly to better fit the substrate.

Ionic bond

A bond formed when electrons are transferred from one atom to another, creating charged ions that attract each other.

Ligand

A molecule that binds specifically to a receptor or protein

Lipid

Hydrophobic biomolecule including fats, oils, phospholipids, and steroids; used for energy storage and membranes.

Lock and key

Enzyme model where the active site has a fixed shape that matches only a specific substrate.

Monosaccharide

The simplest carbohydrate (sugar unit), e.g., glucose, fructose, galactose.

Nonpolar

A molecule with no significant charge separation; does not mix with water.

Nucleotides

Building blocks of nucleic acids (DNA, RNA); consist of a sugar, phosphate group, and nitrogenous base.

pH scale

A measure of hydrogen ion concentration in a solution; ranges from 0 (acidic) to 14 (basic).

Phospholipid

A lipid with two fatty acids and a phosphate group attached to glycerol; main component of cell membranes.

Polar

A molecule with partial positive and negative charges due to unequal electron sharing.

Polysaccharide

A carbohydrate made of many monosaccharides linked together (e.g., starch, glycogen, cellulose).

Proteins

Large biomolecules made of amino acids; perform structural, enzymatic, transport, and signaling functions.

Primary protein structure

The linear sequence of amino acids in a protein.

Secondary protein structure

Local folding of a protein chain into alpha-helices or beta-sheets due to hydrogen bonding.

Purine

A double-ring nitrogenous base (adenine and guanine in DNA/RNA).

Pyrimidine

A single-ring nitrogenous base (cytosine, thymine in DNA, uracil in RNA).

Quaternary protein structure

The arrangement of multiple protein subunits into a larger complex.

Saturation

Refers to fatty acids; “saturated” means all single bonds (no double bonds), while “unsaturated” has one or more double bonds.

Steroid

A type of lipid with four fused carbon rings; includes cholesterol, testosterone, estrogen.

Tertiary protein structure

The overall 3D folding of a single protein chain, stabilized by various bonds and interactions.

Van der Waals forces

Weak attractions between molecules due to temporary shifts in electron distribution.

What are the 4 biomolecules

lipids, carbohydrates, proteins, nucleic acids

What are the 4 biological roles of e-

Form covalent and ionic bonds, store energy, redox reactions

Factors contributing to protein shape

H-bonds, ionic bonds, van der Waals forces