Cell Biology and Organelles

Comprehensive vocabulary flashcards covering cell theory, prokaryotic and eukaryotic classifications, cellular organelles, and specialized structures from biology lectures.

What is a cell

The smallest unit capable of performing life functions (the basic unit of life), whose primary function is to make proteins.

Who is the scientist who first discovered cells

Robert Hooke in 1665.

The Cell Theory

A fundamental biological principle composed of three tenets: 1) all living things are made of cells, 2) cells are the smallest unit of life, and 3) all cells come from pre-existing cells.

Prokaryotic Cell

The most basic type of cell; it lacks a nucleus and membrane-bound organelles, leaving its DNA free-floating in the cytoplasm.

Eukaryotic Cell

A complex cell containing membrane-bound organelles and a nucleus that encloses its genetic material (DNA).

Bacteria

A kingdom under domain Prokaryote consisting of simple, single-celled organisms that divide by binary fission and are very small.

Archaea

A kingdom of simple unicellular prokaryotic organisms that live in extreme environments.

Protists (Protista)

A kingdom of unicellular and complex eukaryotes that are diverse (can be animal- or fungus-like) and undergo asexual reproduction (e.g., Slime mold, Amoeba, Euglena, Dinoflagellate, Paramecium, Diatom).

Fungi

A kingdom of eukaryotic organisms that can be unicellular or multicellular and absorb their own food.

Binary Fission

The process of prokaryotic cell division occurring in four stages: 1) the parent cell initiates replication, 2) a copy of the cell's DNA is created, 3) the cell elongates and a cross wall forms, and 4) the cross wall completes and daughter cells separate.

Cell Membrane

A barrier that surrounds the cell and controls what enters and exits the cell.

Cytoplasm

A gel-like watery plasma fluid taking up most of the cell that holds organelles in place and is composed of cytosol and organelles, where cell functions are carried out.

Cytosol

The fluid component of the cytoplasm.

Nucleus

The control center of a eukaryotic cell and location of DNA, which coordinates cellular activity and function, contains chromosomes at the site of ribosome synthesis, and is enclosed by the nuclear envelope.

Mitochondria

Oval-shaped eukaryotic organelles known as the powerhouse of the cell; the site of energy production that generates energy in the form of ATP and is best viewed under an electron microscope.

Cristae

The folded inner membrane found inside a mitochondrion.

Matrix

The inner fluid component of a mitochondrion.

Ribosome

A small structure composed of RNA and proteins found in both prokaryotes and eukaryotes that serves as the site of protein synthesis (translation).

Endoplasmic Reticulum (ER)

An interconnecting system of thin membranes dividing the cytoplasm into compartments and channels that serves as the cell transport system and folds proteins.

Rough Endoplasmic Reticulum

Endoplasmic reticulum studded with ribosomes, used for quicker modification and sending of proteins.

Smooth Endoplasmic Reticulum

Endoplasmic reticulum with no ribosomes attached that performs diverse functions and is frequently found in liver and gut cells.

Golgi Apparatus

An assembly of vesicles and folded membranes that modifies materials (such as adding carbohydrates), packages them in vesicles, and transports them around the cell.

Lysosome

An animal cell organelle consisting of membrane-enclosed digestive enzymes that recycles old, foreign, or excess cellular parts, participates in apoptosis, and is formed by the Golgi apparatus.

Apoptosis

Programmed cellular death, a process in which lysosomes play an active role.

Cytoskeleton

A flexible, 3-D structure that provides shape to the cell and can change shape, composed of microtubules and microfilaments.

Microtubules

Tubular structures that form part of the cell cytoskeleton.

Microfilaments

Solid bundles that make up part of the cell cytoskeleton.

Cell Wall

A water-permeable protective layer composed of cellulose found in plant cells that surrounds the cell membrane, provides structure, and serves as a barrier against infection.

Chloroplast

A plant cell organelle containing green pigments (chlorophyll) that serves as the site of photosynthesis and is composed of thylakoids and stroma.

Thylakoids

Membrane stacks located within a chloroplast.

Stroma

The fluid component situated inside a chloroplast.

Vacuole

A storage organelle holding water, sugars, and minerals that is large, permanent, and able to expand in plant cells, while being much smaller in animal cells.

Amyloplast

A specialized plant cell organelle that stores starch grains.