What is Life?

A “little” history… theory

7 MUST HAVE Characteristics of Living Things: 1. It obtains and uses energy 2. It grows and develops 3. It reproduces 4. It responds to the environment including movement 5. It breathes/respires (exchange of gasses) 6. It produces waste 7. It is made up of cells

Is it made up of cells? Cells Eukaryotes (has a nucleus) Unicellular Ex. Protists Multicellular Ex. Plants and Animals Prokaryotes (No Nucleus) Ex. bacteria

A View of the Cell Cell Features

Discovering the Cell Robert Hooke – used a microscope to study cork; coined the term “cell” b/c they looked like cells in a monastery where monks lived! Anton van Leeuwenhoek – first person to record looking at water under a microscope

Matthias Schleiden – Observed that plants are composed of cells Theodor Schwann – Observed that animals are composed of cells Rudolph Virchow – Determined that cells come from other cells; cells are not spontaneously generated.

I. Introduction to the Cell Cell Theory – All living organisms are made up of one or more cells. – Cells are the basic unit of structure & function in organisms. – All cells come from preexisting cells.

Cells are the building blocks of you. Cells form tissue Tissue forms organs Organs form systems Systems form organisms

Reflection: Why is this important? It helps us to understand how we are made and how we are similar.

Success is: Listening and taking good notes Coloring the cells correctly

Cell Shape—they can all be different! The shape of a cell depends on its function.

– Most cells contain a variety of membrane- bound ORGANELLES - cell parts that PERFORM SPECIFIC FUNCTIONS FOR THE CELL Internal Organization

– A Large Organelle near the Center of the Cell is the NUCLEUS. IT CONTAINS THE CELL'S GENETIC INFORMATION (DNA) AND CONTROLS THE ACTIVITIES OF THE CELL. – DNA – Genetic information located in chromosomes “BRAIN” of the cell

Other Organelles MITOCHONDRIA – this bean-shaped structure is the cell’s energy center. It turns sugars into chemical energy. “Powerhouse” of the cell

Other Organelles CYTOPLASM – jelly-like substance that support/protects the organelles VACUOLE – storage area for water and other substances, plant cells usually have one large central vacuole (animal cells have 2-3 small vacuoles)

CELL MEMBRANE Selectively permeable (semi-permeable) ; it regulates what comes into the cell and what leaves the cell Provides support and protection Similar to our skin

Have additional structures CELL WALL – surrounds the membrane and provides additional support CHLOROPLASTS – contain green pigment called Chlorophyll, used in photosynthesis CENTRAL VACUOLE – large water container in the center of the cell Plant Cells