Cells: The Basic Units of Life

The Cell Theory 1.All organisms are composed of one or more cells. 2.The cell is the basic unit of life in all living things. 3.All cells come from existing cells.

Organelles Organelles are chemicals and structures that enable the cell to live, grow and reproduce.

Two Types of Cells Prokaryotic Cells: Have no membrane covered nucleus Have no membrane - covered organelles Have circular DNA Are bacteria

Two Types of Cells Eukaryotic Cells: Have a nucleus Have a membrane - covered organelles Have linear DNA Are all other cells

Hereditary Material and Cytoplasm Hereditary Material in the cell is DNA. DNA controls all the activities of the cell. Cytoplasm is the fluid contained in the cell.

Cell Membrane Keeps cytoplasm inside the cell Provides a barrier between the inside and the outside of the cell Allows nutrients into the cell and wastes outside of the cell Cell Membrane

Cell Wall Found only in plant cells Made of cellulose Provides strength and support for the cell When too much water enters the plant cell, the wall prevents it from exploding.

The Nucleus The largest most visible organelle in the cell The control center of the cell Contains the Cell’s DNA DNA Nuclear Membrane Nucleolus

Ribosomes Smallest most abundant organelles Found in all cells The site where amino acids are hooked together to make proteins Does not have a membrane

Endoplasmic Reticulum Membrane covered compartment Makes lipids and other materials for use inside and outside the cell Breaks down chemicals that can damage the cell It is the internal delivery system for the cell Ribosomes Endoplasmic Reticulum

Mitochondria Site where ATP is made It is surrounded by two membranes Can only work if Oxygen is present Outer Membrane Inner Membrane

Chloroplasts Found only in plant cells Has two membranes Contains chlorophyll, which makes chloroplasts green Sun’s energy is trapped in chlorophyll to make sugar This process is called photosynthesis Inner Membrane Outer Membrane

Golgi Complex Where proteins and other materials are processed and shipped Lipids and proteins are modified here for different functions Final products are enclosed in a piece of membrane that breaks off and transports to other parts of the cell or outside of the cell

Vacuole Found only in Plants Large membrane - covered chamber Stores water and other liquids Vacuole

Lysosomes Found in animal cells Digests food particles and cell parts Protects cell by digesting foreign invaders When they break they cause the destruction of the cell

Plant or Animal Cell? Found in Plant and Animal cells:Found only in Plant Cells: Nucleus Golgi Complex Mitochondrion Lyosomes Endoplasmic Reticulum Cell Membrane Ribosomes Chloroplasts Vacuoles Cell Wall