The Structural Basis of Life

Vocabulary flashcards covering the chemical composition of the human body, clinical laboratory values, cellular structures, and membrane transport mechanisms.

Carbon (C)

A major element ($18\%$ of body weight) that serves as the backbone of organic molecules.

Nitrogen (N)

A major element ($3.2\%$ of body weight) found in proteins, $DNA$, and $RNA$.

Calcium (Ca)

A minor element essential for bones, teeth, and muscle contraction with a normal blood serum level of $8.5 - 10.5\,mg/dL$.

Hypercalcemia

The medical term for increased levels of calcium in the blood serum.

Hypocalcemia

The medical term for decreased levels of calcium in the blood serum.

Phosphorus (P)

An element found in $ATP$, $DNA$, $RNA$, and bones that binds to calcium; normal level is $2.5 - 4.5\,mg/dL$.

Potassium (K)

An element required for nerve impulses and muscle contraction with a normal blood serum level of $3.5 - 5.0\,mEq/L$.

Hyperkalemia

The condition of having increased levels of potassium in the blood serum.

Sodium (Na+)

An element responsible for fluid balance and nerve transmission with a normal blood serum level of $135 - 145\,mEq/L$.

Hyponatremia

The medical condition resulting from decreased levels of sodium in the blood serum.

Chlorine (Cl)

An element involved in stomach acid ($HCl$) and fluid balance; normal level is $98 - 106\,mEq/L$.

Magnesium (Mg)

A minor element necessary for enzyme function and muscle/nerve activity; normal level is $1.5 - 2.5\,mg/dL$.

Iron (Fe)

An element found in hemoglobin responsible for oxygen transport; normal levels are $65 - 175$ for males and $50 - 150$ for females.

Trace Elements

Elements needed in very small amounts ($< 0.1\%$) such as Zinc ($Zn$), Copper ($Cu$), Iodine ($I$), and Fluorine ($F$).

Homeostasis

A characteristic of living matter referring to the maintenance of a stable internal environment.

Metabolism

A characteristic of living matter involving chemical processes that occur within a living organism to maintain life.

Prokaryotic cell

A simple, single-celled organism that lacks a nucleus and contains $DNA$ in a nucleoid region (e.g., Bacteria and Archaea).

Eukaryotic cell

A complex cell containing a nucleus and specialized organelles; examples include Animal, Plant, Fungi, and Protist cells.

Virus

A biological entity that is neither Prokaryotic nor Eukaryotic.

Robert Hooke (1665)

The scientist who observed tiny rooms in cork and named them "cells".

Rudolf Virchow (1858)

The scientist who proved that cells only come from other living cells.

Cell Membrane

The "security guard" or outer boundary of the cell that controls what enters and leaves.

Mitochondria

The "powerhouse of the cell" which produces energy ($ATP$) through cellular respiration.

Ribosomes

The site for protein synthesis, found floating in the cytoplasm or attached to the rough $ER$.

Smooth Endoplasmic Reticulum

A part of the $ER$ that lacks ribosomes, makes lipids, and helps detoxify harmful substances.

Golgi Apparatus

The organelle that packages finished molecules into vesicles for transport or secretion.

Lysosomes

Organelles containing hydrolytic enzymes used to break down waste and damaged organelles.

Chloroplast

The site of photosynthesis in plant cells containing the green pigment chlorophyll.

Peroxisomes

Organelles containing enzymes that break down toxic substances and fatty acids.

Fluid Mosaic Model

A model proposed by S.J. Singer and Garth L. Nicolson (1972) describing the cell membrane as a flexible liquid made of phospholipids, proteins, cholesterol, and carbohydrates.

Passive Transport

The movement of substances from a high concentration to a low concentration without using cell energy.

Osmosis

The movement of water across a semipermeable membrane to balance concentration levels.

Active Transport

The movement of substances from a low concentration to a high concentration using cell energy ($ATP$).

Endocytosis

A form of vesicular transport where the cell skin folds inward to swallow large items.

Exocytosis

A form of vesicular transport where a bubble inside the cell fuses with the outer skin to push waste or signals out.