General Biology: Microscopy, Macromolecules, and Cellular Energetics

Comprehensive vocabulary flashcards covering microscopy principles, biological macromolecules, solution tonicity, membrane transport, and cellular energy pathways (glycolysis, fermentation, and cellular respiration).

Light Microscope

A type of microscope that utilizes visible light focused by glass lenses to form an image.

Compound Light Microscope

A microscope designed for small transparent or thinly sectioned specimens that produces two-dimensional flat images.

Dissecting Microscope

A microscope that allows surface viewing of larger unsectioned objects at lower magnifications and produces a three-dimensional image.

Transmission Electron Microscope (TEM)

An electron microscope that utilizes electron beams focused by electromagnets onto a photogenic plate to produce a flat image of extremely small, thinly sectioned stained specimens.

Scanning Electron Microscope (SEM)

An electron microscope that focuses electron beams onto small unsectioned specimens to produce a three-dimensional image of their surface.

Working Distance

The space between the objective lens and the slide on a microscope.

Total Magnification

The overall magnification calculated by multiplying the magnification of the ocular lens by the magnification of the objective lens.

Wet Mount

A temporary preparation of a specimen for microscopic examination.

Organic Compounds

Complex chemical substances characterizing living matter, which include carbohydrates, lipids, proteins, and nucleic acids.

Monosaccharides

The simplest carbohydrates, also known as simple sugars, composed of carbon, hydrogen, and oxygen (such as glucose).

Disaccharides

Carbohydrate molecules, also known as double sugars, formed within cells by joining two monosaccharides through dehydration synthesis.

Polysaccharides

Large carbohydrate molecules formed by the union of many simple or double sugar units via dehydration synthesis, such as plant starches.

Lipids

Fatty compounds containing carbon, hydrogen, and oxygen, where the oxygen content is much lower than in carbohydrates.

Triglycerides

Natural fats or oils synthesized by joining one glycerol molecule and three fatty acid molecules via dehydration synthesis.

Saturated Fatty Acid

A fatty acid molecule that possesses only single covalent bonds between its carbon atoms.

Unsaturated Fatty Acid

A fatty acid molecule that contains double or triple covalent bonds between its carbon atoms.

Proteins

Large molecules containing carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur, assembled from smaller subunits via dehydration synthesis.

Amino Acids

The individual subunits of a protein molecule, each composed of an amino group, an acid group, and a chemically unique R group.

Nucleic Acids

The largest of all organic molecules, such as DNA and RNA, composed of nucleotide subunits containing carbon, hydrogen, oxygen, nitrogen, and phosphorus.

Solvent

A liquid or gas in which smaller amounts of other substances can be dissolved or suspended.

Solute

The substance that is dissolved in a solution.

Solution

A homogeneous mixture of two or more components.

Concentration Gradient

A pathway along which substances move, usually from an area of greater to lesser concentration.

Isotonic Solution

A solution with a solute concentration that is equal to that of a cell placed into it.

Hypertonic Solution

A solution containing more solute or a lower water concentration than the cells placed inside it.

Hypotonic Solution

A solution containing less solute and more water than the cells placed inside it.

Diffusion

The movement of molecules in a gas or solution from an area of greater to lesser concentration toward a uniform distribution of particles.

Osmosis

The movement of water from an area of greater to lesser concentration across a semipermeable membrane.

Crenation

The shriveling of a cell that occurs when it is placed in a hypertonic solution.

Hemolysis

The rupture of a red blood cell when placed in a hypotonic solution.

Adenosine Triphosphate (ATP)

The charged, high-energy molecule acting as the immediate source of energy for cellular processes, composed of adenine, ribose, and three inorganic phosphate groups.

Adenosine Diphosphate (ADP)

The discharged form of adenosine that is recycled back into ATP by combining with an inorganic phosphate group.

Glycolysis

The enzymatic pathway occurring in the cytoplasm that breaks down glucose into two molecules of pyruvate, yielding a net gain of $2$ ATP without consuming oxygen.

Obligate Anaerobes

Bacterial cells that cannot tolerate the presence of free oxygen and rely solely on glycolysis to generate ATP.

NAD (Nicotinamide Dinucleotide)

A coenzyme that acts as an acceptor for hydrogen ions during glycolysis, becoming reduced to $\text{NADH} + \text{H}^+$.

Fermentation

Anaerobic biochemical pathways that convert excess pyruvate to restore supplies of NAD for continued glycolysis without producing additional ATP.

Cellular Respiration

The oxygen-requiring mitochondrial process that oxidizes pyruvate to carbon dioxide and water, generating up to $36$ ATP per glucose molecule.