Physiology, Homeostasis, and Biomolecules Vocabulary

Vocabulary practice flashcards covering fundamental physiological definitions, homeostatic themes, feedback loop steps, chemical bonds, and functional categories of biomolecules.

Physiology

The study of how ions, biomolecules, organs, and organ systems all work synergistically to maintain homeostasis.

Pathophysiology

The study of body function during disease states or when the organism fails to compensate and maintain homeostasis.

Homeostasis

Maintaining a constant internal environment, with every physiological variable at or near a specific value or set point, despite changes inside or outside the body.

Law of Mass Balance

The principle stating that for the body to remain in a constant state, additions must be met with equal subtractions (either through use or removal), and vice versa.

Teleological Perspective

A physiological perspective that explains "why" an anatomical feature exists or "why" a change in function occurs by describing its adaptive significance or survival benefit.

Mechanistic Perspective

A physiological perspective that describes "how" a system works or explains its physiological basis step-by-step.

Extracellular Fluid (ECF)

Aqueous fluid located outside of cells, which exists as interstitial fluid for tissue cells or plasma for blood cells.

Intracellular Fluid (ICF)

Aqueous fluid located inside the cells of the body.

Structure/Function Map

A diagram used to organize or chunk vocabulary terms and concepts by level of complexity, starting with a general category that branches down into sub-categories.

Process Map

A sequential diagram or flow chart depicting a process or series of events happening through time.

Generic Feedback Loop

A specialized 8-step process map showing how the body maintains homeostasis through a specific sequence: stimulus, sensor, afferent pathway, integrating center, efferent pathway, effector, effector's action, and response.

Stimulus

Any physiological change that deviates from the body's preferred set point.

Sensor

A physical, anatomical structure (such as a chemoreceptor, thermoreceptor, osmoreceptor, baroreceptor, proprioceptor, or photoreceptor) that detects a deviation from a set point.

Afferent Pathway

The pathway that carries sensory information from a sensor going to an integrating center.

Integrating Center

An anatomical structure (such as the medulla oblongata) where incoming sensory data is interpreted, compared to a stored set point, and used to determine an optimal response.

Efferent Pathway

The pathway carrying output signals leaving an integrating center toward an effector.

Effector

A specific anatomical structure that works to counteract a stimulus and return a physiological variable to its set point.

Effector's Action

The specific process or physical action performed by an effector to restore homeostasis.

Response

The outcome of an effector's action, which opposes the stimulus in a negative feedback loop or pushes the stimulus further from the set point in a positive feedback loop.

Covalent Bond

A very strong chemical bond formed when atoms share valence electrons, requiring extreme heat or enzymes to break.

Ionic Bond

A chemical bond formed by the transfer of valence electron(s) from one atom to another, which readily breaks in aqueous solutions.

Hydrogen Bond

A weak bond occurring between the hydrogen atom of one polar molecule and a polar atom of a separate molecule.

Van der Waals Forces

Very weak attractive forces between the protons of one atom and the electrons of any nearby atom.

Buffer

A molecule that minimizes changes in pH by taking or contributing $H^+$ ions when their concentration becomes low or high.

Bicarbonate Ion

The primary buffer in human blood ($HCO_3^-$) that binds excess $H^+$ ions to become carbonic acid ($H_2CO_3$).

Carbohydrates

The most abundant category of biomolecules ($C_xH_{2x}O_x$), composed of carbon, hydrogen, and oxygen in ring structures, primarily used to produce ATP and act as cellular identification tags.

Glycosidic Bond

The covalent bond that attaches monosaccharides together to form disaccharides or polysaccharides.

Glycogen

A polysaccharide polymer of glucose that serves as the main storage form of carbohydrates in animals.

Lipids

The only category of non-polar, hydrophobic biomolecules consisting mostly of carbon and hydrogen with few oxygens, functioning as energy sources, cell membrane structural components, or signaling molecules.

Fatty Acids

The monomer building blocks of lipids, consisting of hydrocarbon tails that can be saturated (single bonds only) or unsaturated (containing one or more double bonds).

Triglycerides

Lipid polymers composed of one glycerol molecule attached to three fatty acids by ester bonds, acting as the storage form of fat in adipose tissue.

Ester Bond

The covalent bond linking a glycerol molecule to a fatty acid chain in lipid molecules.

Phospholipids

Amphipathic lipid-related molecules containing both hydrophobic and hydrophilic regions that form structural cell membranes.

Nucleotides

Biomolecule monomers composed of a nitrogenous base, a monosaccharide (deoxyribose or ribose), and a phosphate functional group.

Phosphodiester Bond

The covalent bond linking individual nucleotide monomers into nucleic acid polymers like DNA and RNA.

ATP (Adenosine Triphosphate)

An energy-storing nucleotide molecule used to power cellular work, which can also serve as a neurotransmitter.

Amino Acids

The monomer building blocks of all proteins, consisting of an amino group ($-NH_2$), a carboxylic acid group ($-COOH$), and a unique functional R-group.

Essential Amino Acids

The 9 amino acids that the human body cannot synthesize and must obtain through the diet.

Non-Essential Amino Acids

The 11 amino acids critical for maintaining homeostasis that the body can synthesize from other biomolecules.

Peptide Bond

The covalent bond joining amino acids together, formed via a dehydration synthesis reaction.

Primary Structure

The specific linear sequence of amino acids in a protein held together by peptide bonds.

Secondary Structure

Protein structural shapes (alpha helices and beta pleated sheets) formed when nearby R-groups interact through covalent, hydrogen, or ionic bonds and van der Waals forces.

Disulfide Bonds

Strong covalent bonds formed between sulfur atoms in two cysteine amino acids located in close proximity within a protein.

Tertiary Structure

The three-dimensional bending and folding of secondary structures relative to each other into stable globular or fibrous forms in an aqueous environment.

Quaternary Structure

A level of protein organization formed when two or more distinct tertiary-level subunits attach to create a fully functional protein complex like hemoglobin.

Denaturation

The loss of a biomolecule's (especially a protein's) normal three-dimensional structure and function caused by changes in environmental factors like temperature or pH.

Ligand

A molecule or ion that binds noncovalently to a specific binding site or active site on a protein surface to perform cellular work.

Affinity

The degree of attraction and bond strength between a protein and its ligand or substrate.

Specificity

The structural compatibility requiring a protein and its ligand to fit together like a lock and key.

Kinase

An enzyme that carries out covalent modulation by transferring a phosphate functional group from ATP to a target protein.

Phosphatase

An enzyme that removes a phosphate functional group from a protein during covalent modulation.

Saturation

The state where all binding sites on a fixed concentration of proteins are occupied by ligands, preventing any further increase in the rate of work.

Up-Regulation

The process where a cell increases its concentration of protein workers through protein synthesis to achieve higher rates of activity and prevent saturation.

Interstitial fluid

The extracellular fluid that surrounds most cells in body tissues and organs is called

Plasma

The extracellular fluid for blood cells is called

Plasma membrane

This outer surface of the cell is composed mostly of lipids and embedded proteins

Cytoplasm

The ______ includes all fluid and solid material inside the cell membrane (inclusions and organelles), except the nucleus

Inclusions

These are particles of insoluble material inside a cell that are sometimes called non-membranous organelles

Cytoskeleton

Insoluble protein fibers form the cell’s internal support system, which is collectively called its

Nucleus

This organelle in the cell contains all the genetic material used to make proteins and control cell processes

Ribosomes

small, dense granules of RNA and protein that manufacture proteins under the direction of the cell’s DNA and mRNA.

Endoplasmic Reticulum

This organelle is a network of interconnected membrane tubes that can have either a rough or smooth appearance. Inside its lumen, protein modification or lipid synthesis can occur.

Mitochondria

These organelles have their own genetic material and are the primary site of aerobic energy production in the cell.

Golgi apparatus

This organelle receives proteins made in the rough endoplasmic reticulum and packages them into vesicles for movement around the cell or secretion out of the cell.

Lysosomes

These are small storage vesicles that contain powerful enzymes that help to remove cellular components that are no longer needed.

Reactants

In the reaction I +J --> P + Q, the letters “I” and “J” represent what?

Products

In the same reaction shown in Question 1, the letters “P” and “Q” represent what?

Enzyme

If there was a word (i.e., name of a protein) written above the arrow in the reaction in Question 1, it would be a(n) ______ that catalyzes the reaction.

Kinetic

energy is the general term used to describe energy of motion

Potential

stored energy.

Free energy

The energy stored in the chemical bonds of a molecule and available to perform work once that bond is broken is called the ________ of the molecule.

Activation energy

In most biological reactions, some energy must be invested to start the reaction. This energy is called _________.

Exergonic

Some reactions break chemical bonds, make simpler molecules from complex ones, and release free energy for use elsewhere. An excellent example of this kind of reaction is ATP --> ADP + Inorganic Phosphate (Pi) + energy. These sorts of reactions are called ____.

Endergonic

Other reactions require the input of energy to form new chemical bonds, thus creating more complex molecules from simpler ones and storing free energy in those new chemical bonds. An excellent example of this kind of reaction is ADP + Inorganic Phosphate (Pi) + energy --> ATP. These sorts of reactions are called ______.

ATP

This molecule is the primary energy source for biological reactions.

Reduced

When a molecule gains a high-energy electron (and an H+ ion) during a chemical reaction, that molecule is said to be _________

Oxidized

When a molecule loses a high-energy electron (and an H+ ion) during a chemical reaction, that molecule is said to be ________

Phosphorylation

When a molecule gains a phosphate group during a chemical reaction, it has undergone this type of reaction

Kinase

An enzyme that transfers (or exchanges) a phosphate group from one molecule to another is generally called a ___________

Dehydration

In _______ reactions, a water molecule is removed or released to build a larger molecule from several smaller ones.

Hydrolysis

In _______ reactions, one large substrate molecule is split into several smaller molecules through the addition of a water molecule to the reaction.

Dehydrogenase

An enzyme that removes high-energy electrons and H+ ions from a reactant is called what?

Phosphorylase

This kind of enzyme adds phosphate groups from an inorganic source (like HPO4) to other molecules.

Phosphatase

This kind of enzyme removes phosphate groups from molecules and releases them freely into the solution.

Transaminase

This kind of enzyme transfers an amino group from one molecule to another.

Synthetase

This kind of enzyme will join two substrates using the energy from ATP.

Peptidase

An enzyme that splits proteins into smaller fragments or single amino acids through the addition of water is called what?

DNA polymerase

Builds DNA

Isozymes

Two (or more) forms of the same enzyme that have slightly different functions

Reaction cascade

One reaction leads to another and repeats until end reaction

Feedback inhibition

The end product can tell the starting reaction to stop production, helps with regulation, and is usually a allosteric inhibition.

Metabolism

The sum of all energy changes in an organism, including the processes of catabolism and anabolism.

Catabolism

Big large complex molecules are broken down into smaller, simpler units, releasing energy in the process.

Anabolism

Smaller molecules form larger molecules to store energy.

Energy pathways

Anaerobic and Aerobic

Anaerobic pathways

ATP-CP, and Glycolysis

Aerobic pathways

Citric Acid Cycle, Electron Transport cycle

Mitochondria

Location of aerobic pathways

Cytosol

Anaerobic pathway location

ATP-CP System

Very fast way to make ATP