Characteristics of Living Things All organisms are made

Characteristics of Living Things All organisms: • are made of 1 or more cells. • need a source of energy for life processes. • must respond to their environment to survive. • must have the ability to reproduce.

Cell Theory

Major Principles 1. All organisms are made of cells. 2. All existing cells are produced by other living cells. 3. The cell is the most basic unit of life.

Cell Types • Prokaryotes § No membrane-bound nucleus or organelles • Eukaryotes § Made up of one or more cells § Nucleus & membrane-bound organelles

Prokaryote

Eukaryote

Parts of the Cell • All cell types have: § Plasma Membrane - cells outer boundary § Cytoplasm - fluid inside the cell § Control center - nucleus in eukaryotic cells, DNA in cytoplasm in prokaryotic cells • Only eukaryotic cells have organelles

Plasma Membrane Controls what goes in and out of the cell

Cytoplasm • Cell’s liquid interior • Contains the cytoskeleton • Contains organelles

Nucleus In Eukaryotic Cells Controls all cell’s activities Contains DNA

Nuclear Envelope Separates DNA from cytoplasm in the nucleus

Nucleolus • In the nucleus • Made of proteins & nucleic acids • Ribosome synthesis

Ribosome • Contains RNA • Helps build proteins • Made in the nucleolus

Mitochondrion • Generates ATP (energy) • Controls cell cycle & cell growth • Inherited from your mother

Endoplasmic Reticulum (ER) Production & movement of proteins throughout the cell

Golgi Apparatus Processes & packages lipids & proteins

Lysosome Digests food & worn-out cell parts for the cell

Cilia & Flagella Cilia • Single-celled organisms • Helps move the cell around • Cilia – many & short Flagella • Flagella – few & long

Cell Wall • Outside of the cell membrane • Provides support & protection • Plant cells

Central Vacuole • Storage unit for cells • Contains wastes, food, or water

Chloroplast Conducts photosynthesis