Cells and Microscopes Vocabulary

Flashcards covering vocabulary, concepts, organelle functions, and chemical processes from the Cells and Microscopes lecture notes.

Cell

The basic structural unit and simplest form of life that makes up all living organisms.

Micron (Micrometre)

A unit of length equal to $10^{-6}\,m$ or $0.001\,mm$, represented by the symbol $\mu m$.

Cell Theory

A biological principle stating that all living things are composed of one or more cells, cells are the basic units of life, and all cells arise from pre-existing cells.

LUCA

An acronym for Last Universal Common Ancestor, referring to the common ancestral organism from which all cellular life on Earth descended.

Field of View (FOV)

The diameter of the circular area that is visible when looking through a microscope lens.

Magnification

The ratio of image size under a lens compared to the size of the object viewed with the naked human eye.

Stereoscope

A microscope that utilizes two eyepieces and two objective lenses to provide a three-dimensional view of a sample at a typical total magnification of $20\times$.

Biotic

Refers to living or once-living components of an ecosystem that are composed of cells, such as leaves and flowers.

Abiotic

Refers to non-living matter that is not composed of cells, such as water, rocks, wind, and soil.

Prokaryote

A small, simple unicellular organism that lacks a nucleus and membrane-bound organelles, storing its genetic material directly in the cytoplasm.

Eukaryote

A larger, complex unicellular or multicellular organism containing a distinct, membrane-bound nucleus and specialized cellular organelles.

Unicellular Organism

An organism composed of only a single cell, such as bacteria, archaebacteria, or yeasts.

Multicellular Organism

An organism composed of multiple cells that can form complex structures such as tissues, organs, and systems.

Phospholipid

A lipid molecule consisting of a hydrophilic (water-attracting) phosphate head and a hydrophobic (water-repelling) lipid tail that forms the double layer of cell membranes.

Agar

A jelly-like substance derived from algae that provides a moist surface for culturing and growing colonies of microorganisms.

Colony

A visible group of microorganisms growing on a solid medium that originated from the multiplication of a single cell.

Nucleus

A sphere-shaped organelle surrounded by a nuclear envelope that holds and protects the cell's genetic code (DNA).

Cytoplasm

A gel-like interior environment rich in water that houses cellular components and includes a structural cytoskeleton.

Cell Membrane

A flexible phospholipid double layer enclosing the cell that provides protection and selectively filters the entry of nutrients and exit of waste products.

Mitochondria

Organelles known as the powerhouses of the cell that generate chemical energy in the form of $\text{ATP}$ through cellular respiration.

Rough Endoplasmic Reticulum (RER)

A membrane network covered with ribosomes that manufactures proteins and transports them in vesicles.

Smooth Endoplasmic Reticulum (SER)

A membrane network lacking ribosomes that functions primarily in producing new cell membrane lipids.

Ribosomes

Small cellular structures that translate genetic instructions from DNA to construct proteins.

Golgi Apparatus

An organelle functioning as the cell's post office, responsible for modifying, packaging, and shipping molecules received from the endoplasmic reticulum.

Vesicle

A small, membrane-enclosed sac used by the cell to transport materials internally or to the cell exterior.

Lysosome

A specialized organelle containing digestive enzymes that breaks down cellular food, waste products, and foreign invaders.

Cell Wall

A rigid structural layer surrounding the cell membrane in plant cells and prokaryotes, providing shape and protection.

Large Vacuole

A prominent membrane-bound organelle in plant cells utilized for storing water, nutrients, and pigments.

Chloroplast

An organelle containing green chlorophyll pigment found in plant cells that converts solar energy into chemical energy through photosynthesis.

Photosynthesis

The biological process by which chloroplasts convert light energy, carbon dioxide, and water into glucose and oxygen: $CO_2 + H_2O \rightarrow C_6H_{12}O_6 + O_2$.

Cellular Respiration

The metabolic reaction in mitochondria that breaks down glucose and oxygen to yield usable energy ($\text{ATP}$), carbon dioxide, and water: $C_6H_{12}O_6 + O_2 \rightarrow CO_2 + H_2O + \text{ATP}$.

Reactants

The starting chemical substances that undergo change during a chemical reaction.

Products

The output chemical substances formed as a result of a chemical reaction.

Lipids

Essential organic fat molecules required for cell membrane structure and long-term storage.

Carbohydrates

Organic molecules, including simple and complex sugars, that serve as the main source of energy for cellular functions.

Proteins

Complex organic molecules composed of amino acid chains that serve as cellular structural elements, enzymes, transporters, and hormones.