Cells Chapter 2

What is Life? Characteristics of living things – _____________ – _______________ – ______________ – ________________________ – ________________ – ___________ Cells Contain Chemicals Use Energy Respond to their Surroundings Grow and develop Reproduce

Cells - Cellular Organization Unicellular - Multicellular- basic unit of structure and function in an organism – microscopic Single celled (bacteria) Many cells that are specialized to do certain tasks Example: muscle and nerve cells perform certain tasks in the body to help us move and feel.

Scientists and their Discoveries Cells were not discovered until the invention of the _____________. __________________-made a simple microscope to examine the thin layers of cork (1655). Hooke called the structures that he saw in the microscope _________. _________________stated that cells can only come from other living things (1855) Microscope Robert Hooke Rudolph Virchow “Cells”

Cell Theory _________________ has three parts. 1. All living things are made of one or more cells. 2. Cells are the basic units of living things 3. All cells come from existing cells – Cells perform certain ________________: 1. A cell must get, store, and release energy 2. Cells must make _________, release ________, and _____________ materials. Cell Theory proteins wastesrecycle life functions

Organelles _______________are structures that perform specific functions within a cell. Organelles in an animal cell: 1. ____________________ a. network of folded membranes. b. Transport system c. Makes proteins and other substances needed by the cell Organelles Endoplasmic Reticulum

Organelles in an animal cell continued 2. ________-control center of the cell a.Directs the cells activities b.Contains the cells operating instructions c.Stores information that will be passed along to new cells. 3._____________ a.Contains fluid b.Surrounded by a membrane c.Store water and nutrients d.Help the cell digest food Nucleus Vacuole

Organelles in an animal cell continued 4._______________ begins the process of making proteins 5.____________- “Powerhouse of the cell” 8convert the chemical energy from food into a form that the cell can use 6._____________-maintains the internal environment of the cell by allowing food to enter and wastes to exit. Ribosomes Mitochondria Cell Membrane

Organelles in an animal cell continued 7.______________fluid substance containing the organelles 8._____________contain powerful chemicals that breakdown harmful molecules - Different kinds of cells have different organelles. Example: Muscle cells have several ________________because muscle cells need a lot of energy for movement. Skin cells have very few mitochondria. Cytoplasm Lysosome Mitochondria

Organelles in Plant Cells 1.______________-rigid wall outside of the cell membrane that provides support (animal cells do not have a cell wall!) 2.______________-plant cells have one large vacuole. (animal cells have several smaller vacuoles!) 3.______________-contain chlorophyll which is used for photosynthesis (Animal cells do not have chlorophyll. Cell wall Vacuole Chloroplast