Cell Theory

Characteristics of Life Organization The ability to grow and develop The ability to respond to the environment The ability to reproduce

Theory A theory is a widely accepted explanation of things observed in nature. Theories are important because they serve as foundations for further research and study, and can lead to research that is beneficial to society.

Cell Theory Every living thing is made of cells. The cell is the basic unit of structure and function of all living things. Cells come only from other living cells by cell division.

Cell Structures and Functions

2 Types of Cells: Prokaryotic Eukaryotic Has a nucleus No nucleus Organelles have no membranes Very small Eukaryotic Has a nucleus Organelles have membranes Much larger

Prokaryote Eukaryote

Two Types of Prokaryotic Cells Eubacteria: Common bacteria Smallest Cells No nucleus, but do have DNA Archebacteria: Similar to bacteria, but can live in places no other organisms can live (such as high salt or high heat environments

Two Types of Eukaryotic Cells Plant Cells: Make up plants Have a cell wall Have chloroplasts Makes its own food Vacuoles are large Animal Cells: Make up animals No cell wall No chloroplasts Cannot make own food Vacuoles are small

Animal Cell

Plant Cell

Cell Organelles Organelles are the tiny working parts of cells. All organelles are specialized. All cells have organelles which help to carry out the processes for life

Animal & Plant Cell Organelles: Cell membrane-the outer layer of the cell; separates the cell from the outside environment Cytoplasm-the jelly-like fluid that takes up most of the inside of the cell; all interior organelles are suspended in the cytoplasm; gives the cell shape and support

Animal & Plant Cell Organelles: Vacuole-small in animal cell; it stores water and other materials. Mitochondria-breaks down food molecules for energy to sustain the cell. Lysosome-digests food particles, wastes, and foreign particles.

Animal & Plant Cell Organelles: Ribosomes-where proteins are made in the cell Nucleus-largest organelle in the cell; contains DNA and is the control center for the cell Nuclear Membrane-Contains most of the animal cell organelles

Plant Cell Organelles Vacuole- Is MUCH larger in a plant cell Cell Wall- Is much more rigid than only having a cell membrane. Makes cell look square Chloroplast- Uses energy from the sun to make food; makes plants appear green