Cell Theory and Cell Composition

These flashcards cover key vocabulary terms related to cell theory, cell structure, membrane transport, and cellular functions.

Cell Theory

The fundamental concept stating that all living organisms are composed of cells, which are the basic units of life.

Cytology

The study of cell structure and function.

Cell Membrane (Plasma Membrane)

The boundary of a cell that regulates the exchange of substances with its environment.

Hydrophilic

Substances that are attracted to water and can interact with it.

Hydrophobic

Substances that repel water and do not interact with it.

Passive Transport

The movement of molecules across a cell membrane without the use of energy.

Diffusion

The process by which particles move from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water through a selectively permeable membrane.

Isotonic Solution

A solution with the same solute concentration as inside the cell, resulting in no net movement of water.

Hypertonic Solution

A solution with a higher solute concentration outside the cell, causing the cell to lose water and shrink.

Hypotonic Solution

A solution with a lower solute concentration outside the cell, causing the cell to gain water and possibly burst.

Carrier-Mediated Transport

Transport of substances across a membrane via protein carriers that may involve energy.

Facilitated Diffusion

A form of passive transport that uses carrier proteins to move molecules across the membrane.

Active Transport

The movement of substances against their concentration gradient requiring energy.

Endocytosis

The process of taking substances into a cell by engulfing them in a vesicle.

Exocytosis

The process of expelling substances from a cell by vesicles fusing with the plasma membrane.

Cytoplasm

The material within a cell, excluding the nucleus, that contains cytosol and organelles.

Organelles

Specialized structures within a cell that perform various functions necessary for cell life.

Lysosomes

Membranous organelles containing enzymes for digestion of cellular waste and pathogens.

Ribosomes

Cellular structures responsible for protein synthesis.

Nucleus

The control center of a cell that contains DNA and regulates cellular activities.

Gene

A sequence of DNA that codes for a specific protein and determines hereditary traits.

Mitosis

The process of nuclear division resulting in two identical daughter cells.

Apoptosis

Programmed cell death that occurs in multicellular organisms.

Telomeres

Protective caps on the ends of chromosomes that shorten with each cell division.