Unit 1 Review: Anatomy, Physiology, Chemistry, Energy, and Cell Biology

Comprehensive vocabulary flashcards covering basic anatomy, homeostatic control, chemistry principles, energy and enzymes, and cell structure and function from Unit 1 lecture notes.

Anatomy

The science that studies body structure and the physical relationships among different body parts.

Physiology

The science that studies body functions and how the individual parts of the body work.

Homeostasis

The condition of relative balance or equilibrium within the body's internal environment despite changing external conditions.

Dynamic Process

The concept that homeostasis continuously adjusts around a set point within a narrow normal range rather than remaining completely static.

Negative Feedback

A homeostatic control mechanism that reverses a change in a controlled condition to restore it to its normal range.

Positive Feedback

A homeostatic control mechanism that reinforces or strengthens a change in a controlled condition.

Anatomical Position

A standard reference posture where the body stands erect facing the observer, feet flat on the floor, arms at the sides, with palms turned forward.

Parietal Layer

The outer layer of a serous membrane that lines the internal walls of body cavities.

Visceral Layer

The inner layer of a serous membrane that directly covers and adheres to organs contained within body cavities.

Major Body Mass Elements

The four chemical elements—oxygen, carbon, hydrogen, and nitrogen—that account for $96\%$ of the human body's mass.

Isotope

An atom of an element that possesses the same number of protons but a different number of neutrons compared to other atoms of that element.

Valence Shell

The outermost electron shell of an atom, which determines whether the atom is chemically stable or reactive.

Octet Rule

The chemical principle stating that an atom is most stable when its valence shell contains eight electrons.

Ionic Bond

A chemical bond resulting from the complete transfer of valence electrons between atoms, creating oppositely charged ions.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Covalent Bond

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

Polar Covalent Bond

A covalent bond where electrons are shared unequally between atoms, generating partial positive and negative charges on opposite ends of the molecule.

Nonpolar Covalent Bond

A covalent bond where electrons are shared equally between atoms, resulting in no electrical charges across the molecule.

Amphipathic

A chemical property describing a molecule that possesses both polar (hydrophilic) and nonpolar (hydrophobic) regions.

Hydrogen Bond

A weak attraction between a partial positive charge on a hydrogen atom and a partial negative charge on another polar molecule, represented by a dotted line.

pH Scale

A logarithmic scale ranging from $0$ to $14$ that measures the hydrogen ion ($H^+$) concentration in a solution.

Blood pH Range

The strict physiological homeostatic range of human blood pH, maintained between $7.35$ and $7.45$.

Buffer

A substance or chemical system that prevents drastic changes in pH by binding or releasing hydrogen ions.

Electrolytes

Ions formed when salts dissociate in water that conduct electrical signals in nerve cells and muscle cells (primarily sodium and potassium).

Polymer

A large molecule composed of repeating structural units called monomers bound together.

Monomer

A small, simple subunit that serves as the building block for constructing polymers.

Adenosine Triphosphate (ATP)

The energy currency of the cell, composed of a nucleotide base, ribose sugar, and three phosphate groups, which releases usable energy when high-energy phosphate bonds are broken.

Peptide Bond

The specialized covalent bond formed between two amino acids during protein synthesis.

Protein Denaturation

A structural change where a protein loses its three-dimensional shape and biological function due to altered environmental factors like extreme heat or pH.

Catabolic Reaction

A decomposition reaction that breaks complex molecules into smaller components and releases energy.

Anabolic Reaction

A synthesis reaction that combines simpler components into complex molecules and requires energy input.

Activation Energy

The minimum energy input required to start a chemical reaction.

Enzyme

A protein catalyst that speeds up chemical reactions by lowering the activation energy required.

Active Site

The region on an enzyme where substrate molecules specifically bind to undergo a catalyzed chemical reaction.

Cell

The most basic living functional unit in the human body.

Cytoplasm

The cellular material between the plasma membrane and the nucleus, consisting of fluid cytosol and organelles.

Glycocalyx

A carbohydrate-rich coating on the outer surface of the plasma membrane made of glycolipids and glycoproteins, functioning in cell recognition.

Integral Protein

A membrane protein that extends into or completely across the lipid bilayer of the plasma membrane.

Peripheral Protein

A membrane protein that is loosely bound to the inner or outer surface of the plasma membrane rather than embedded in the lipid bilayer.

Receptor

A membrane protein that selectively binds to specific external chemical messengers (ligands) to initiate a cell response.

Ligand

A specific chemical molecule that binds selectively to a matching receptor on a cell.

Selective Permeability

The property of an intact biological plasma membrane that allows specific substances to pass while blocking others.

Passive Transport

The movement of substances down their concentration gradient across a membrane without requiring cellular energy.

Active Transport

The movement of substances against their concentration gradient across a membrane requiring energy input and membrane protein pumps.

Osmosis

The passive movement of water across a selectively permeable membrane toward a region with higher solute concentration.

Hypertonic Solution

A solution with a higher concentration of non-permeating solutes than the cell cytoplasm, causing water to leave the cell and red blood cells to shrink.

Hypotonic Solution

A solution with a lower concentration of non-permeating solutes than the cell cytoplasm, causing water to enter the cell and red blood cells to swell or burst.

Resting Membrane Potential

The electrical charge voltage difference across the plasma membrane of an unstimulated cell, typically having a default value of $-70\,mV$.

Transcription

The first step of protein synthesis in which a segment of DNA is copied into a complementary messenger RNA strand within the nucleus.

Translation

The second step of protein synthesis occurring at the ribosome, where messenger RNA sequences are decoded to construct amino acid chains.

Somatic Cell

Any biological cell in the body other than a reproductive cell, containing a diploid chromosome count of $46$.