Cell Biology Fundamentals

Comprehensive vocabulary flashcards covering the basics of cell structure, cell theory, microscopy, and specialized organelles based on the lecture notes.

Cell

The basic structural and functional unit of all living organisms; all organisms are made of cells.

Unicellular organisms

Organisms made of only one cell, such as Amoeba and Bacteria.

Multicellular organisms

Organisms made of many cells working together, such as Humans, Dogs, and Mango Trees.

Cell theory

A foundational principle of biology with three postulates: 1. All living organisms are composed of one or more cells. 2. The cell is the basic unit of structure and function. 3. All cells arise from pre-existing cells.

Cell membrane / plasma membrane

A selectively permeable layer that regulates the passage of substances in and out of the cell.

Cytoplasm

A gel-like substance that fills the cell and contains cell organelles; it is the site where cellular processes and metabolic/chemical reactions occur.

Nucleus

The control room of the cell that carries DNA to direct protein synthesis and stores DNA in the form of chromosomes.

Light microscope

An instrument used in laboratories that uses visible light and lenses to magnify specimens up to about $1500 \times$.

Photomicrograph

A photograph taken using a light microscope.

Electron microscope

An instrument that uses a beam of electrons instead of light to magnify objects up to $500,000 \times$, used to see smaller things inside a cell.

Electron micrograph

A picture taken with an electron microscope.

Methylene blue

A biological stain used to make the nucleus of human cheek cells visible under a microscope.

Magnification

A measure of how many times larger an image is compared to the real object, calculated using the formula: $\text{Magnification} = \frac{\text{size of image}}{\text{actual size of object}}$.

Micrometer ($\mu\text{m}$) conversion

A unit of length where 1\text{mm} = 1000\text{\mu m} and 1\text{m} = 10^6\text{\mu m}.

Organelles

Specialized structures in complex organisms that perform specific functions.

Cell wall

A strong protective covering made of cellulose found in plant cells that supports the cell and prevents it from bursting.

Centrosome

A part of an animal cell that helps during cell division; it contains two centrioles.

Centrioles

Small cylindrical structures that help pull chromosomes apart during cell division.

Mitochondria

The powerhouse of the cell responsible for energy production ($\text{ATP}$).

Rough ER ($\text{RER}$)

A form of endoplasmic reticulum with ribosomes attached that is involved in making proteins.

Smooth ER ($\text{SER}$)

A form of endoplasmic reticulum without ribosomes that is involved in making fats.

Golgi apparatus

An organelle involved in the processing and packaging of proteins.

Ribosomes

Structures involved in protein synthesis that are either freely floating in the cytoplasm or attached to the endoplasmic reticulum.

Lysosomes

Known as the suicide bag of the cell, they contain enzymes for cellular digestion; they are absent in red blood cells ($\text{RBCs}$).

Vacuole

A storage sac in plant cells containing cell sap and surrounded by a membrane called the tonoplast.

Tonoplast

The membrane that surrounds the vacuole in plant cells.

Granules

Tiny particles that store substances like food, pigments, or enzymes for the cell.

Nucleolus

A small structure located inside the nucleus that makes ribosomes for the cell.

Chloroplast

A green plant cell organelle containing chlorophyll that makes food through photosynthesis.

Microtubule and microfilament

Components that help the cell stay strong, keep its shape, and move.