Cells: the Basic Units of Life Chapter 3 Cells: the Basic Units of Life

Section 1 – Organization of Life Vocabulary Words Tissue – Group of cells that work together to perform a specific job in the body Organ – When two or more tissues work together this group of tissues is called an organ Organ System – Organs working together to perform a specific job Organism – Anything that can live on its own Unicellular – A single cell living on its own Multicellular – Can only exist as a group of cells Population – Group of organisms that are the same kind living in the same environment Community – Two or more different populations living in the same environment Ecosystem – The community and all the nonliving things that affect it Section 1 – Organization of Life Vocabulary Words

Cells to Tissues to Organs to Organ Systems to Organisms Populations vs. Communities vs. Ecosystems Organization of life

Section 2 – The Discovery of Cells Vocabulary Words Cell Membrane – Surround a cell and acts as a barrier Organelles - Structures that enable the cell to live, grow, and reproduce Cytoplasm – The fluid and almost everything in it Nucleus – Membrane covered organelle that holds the cells’ DNA Prokaryotic – Cells that do not have a nucleus Eukaryotic – Cells that have a nucleus Bacteria – extremely small,single celled organisms without a nucleus; prokaryotic cell Section 2 – The Discovery of Cells Vocabulary Words

The First Cells were discovered by Robert Hooke in 1665 and were cork cells The Cell Theory was written by Theodor Schwann and it states: 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 4. All cells have a: cell membrane, Hereditary material (DNA), Cytoplasm and Organelles, small size Cell Theory

There are two types of cells: PROKARYOTIC: No nucleus No membrane – covered organelles Circular DNA All prokaryotes are bacteria EUKARYOTIC: Nucleus Membrane-covered organelles Linear DNA All other cells

Section 3 – Eukaryotic Cells: The Inside Story Cell Wall – Provides strength and support to the cell membrane: found only in plants Ribosome –Smallest but most abundant organelles where proteins are made from amino acids Endoplasmic Reticulum – Membrane covered organelle that makes lipids and other materials for use inside and outside the cell Mitochondria – Cell Organelles surrounded by two membranes that break down food molecules to make ATP Chloroplast –Energy converting organelle found in plants and algae: found only in plants Golgi Complex – Ships proteins and other materials out of the cell Vesicle – A membrane covered compartment in a eukaryotic cell that forms when part of the cell membrane surrounds an object and pinches off Vacuole – A large membrane covered structure found in plants cells that serves as a storage container for water and other liquids Lysosome - A special vesicle in a cell that digests food particles, wastes, and foreign invaders Section 3 – Eukaryotic Cells: The Inside Story

Organelles and their Functions Nucleus – Contains the cell’s DNA and is the control center of the cell Ribosomes – The site where amino acids are hooked together to make proteins Endoplasmic Reticulum – Makes lipids, breaks down drugs and other substances, packages up proteins for release from the cell. Mitochondria – Break down food molecules to make ATP Chloroplasts – Make food using the energy of sunlight: found only in plants Golgi Complex – Processes and transports materials out of the cell Vacuole – Stores water and other materials Lysosomes – Digest food particles, wastes, cell parts, and foreign invaders