Cell Theory and Cell Functions

Flashcards covering key concepts of cell theory, types of cells, organelles and their functions, and organizational levels in biology.

Cell Theory

Three major tenets: 1) All living things are made of cells. 2) The cell is the basic unit of life. 3) New cells arise from existing cells.

Eukaryotic Cells

Cells that have a true nucleus and membrane-bound organelles; examples include plants, animals, and fungi.

Prokaryotic Cells

Cells that lack a true nucleus and membrane-bound organelles; examples include bacteria.

Cell Membrane

Partially permeable layer surrounding the cell that controls what enters and exits.

Diffusion

Process where molecules move from an area of higher concentration to an area of lower concentration.

Osmosis

The movement of water from a region of higher water potential to a region of lower water potential through a partially permeable membrane.

Active Transport

Movement of molecules from an area of low concentration to an area of high concentration against the concentration gradient, requiring energy.

Vacuole

Storage organelle that holds various substances; large in plant cells for storing water and maintaining turgor pressure.

Chloroplast

Organelle found in plant cells that contains chlorophyll and is the site of photosynthesis.

Mitochondria

Powerhouse of the cell; site of aerobic respiration and ATP production.

Ribosomes

Organelles that synthesize proteins; can be found free in the cytoplasm or attached to the endoplasmic reticulum.

Cell Wall

Rigid outer layer of plant cells that provides shape and structural support; fully permeable.

Tissue

A group of similar cells working together to perform a specific function.

Organ

Different tissues working together to perform a particular function.

Organ System

A group of organs working together to perform closely related functions.