I. Introduction to the Cell “With the cell, biology discovered its atom.” –Jacob A. The cell is the smallest unit that can carry on all processes of life. 1. make energy 2. produce waste 3. reproduce 4. respond to stimulus 5. evolve B. Unicellular: one celled organisms…Protists and Bacteria C. Multicellular: more than one celled organisms D. Discovery of the cell was made possible by the development of glass lenses. 1. Leeuwenhoek (Dutch)- first person to observe living cells 2. Hooke (English)- observed cork from the bark of an oak tree. a. The cells looked like empty compartments similar to cells in a monastery so he named them “cells”

II. Formation of the Cell Theory A. What is the cell theory? 1. all living things are composed of one or more cells 2. cells are the basic unit of life 3. cells only come from other cells B. What they used to believe: Spontaneous Generation (living things come from nonliving things) 1. mud produces fish 2. puddles of water produce microorganisms 3. rotting meat produces flies 4. stale bread produces mold C. A series of experiments were conducted to prove Spontaneous Generation wrong. ificmethod.html

III. Cell Diversity A. Shape 1. different shapes because they have different functions a. nerve cells – long extensions to receive and give messages b. flat skin cells – to protect c. white blood cells change shape so they can move through narrow openings B. Internal organization 1. Eukaryotic Cells2. Prokaryotic Cells nucleus no nucleus membrane bound organelles no membrane bound organelles Ex: plants, animals, fungi, protists Ex: Bacteria

C. Size: there is a limit of size due to the speed at which materials need to get to the center of the cell

D. Difference between plant and animal cells: Plant cellAnimal cell Thick rigid cell wall No cell wall Rectangular shape No rigid shape (roundish) Has chloroplasts No chloroplasts Large central vacuole Some have small vacuoles

IV. Parts of the Cell A. Cell Membrane 1. Separates the cell from its external environment 2. Gives shape and flexibility to the cell 3. Made of 2 layers (“phospholipid bilayer”) 4. Made of fats (phospholipids) and proteins 5. Cholesterol is also a part of the membrane 6. “Fluid Mosaic Model” is how scientists refer to its structure 7. Drawing:

B. Cytoplasm: space within the cell excluding the nucleus 1. jelly like material that contains water, salt, sugars, fats and proteins = cytosol 2. It is always moving C. Organelles—“little organ”, each performs a specific activity 1. Refer to chart on next page. Nucleus is purple, cytoplasm is pinkish. This is a lymphocyte The black stuff

Contains DNA Makes ribosomes

Protects the nucleus Allows things to go in and out of the nucleus

Not membrane bound Makes proteins

Rough because it is covered in ribosomes Makes, packages, and transports protein

Packages and transports protein and fat

Where polysaccharides are made, packaged, and transported Attaches carbohydrate tags to cell membrane proteins

Contains digestive enzymes Breaks down foreign material, old cell parts, and food.

Where food (glucose, fatty acids) is used to make energy (ATP)

Tubulin…the protein that makes up a microtubule Hollow tube that makes up cytoskeleton. Gives cell its shape, helps in movement and helps in cell division

Solid protein thread that makes up cytoskeleton

Adipose Tissue (fat cells store fat in a large central vacuole) Organelle that stores food, waste, and/or water. Plants have 1 large one and animals have many small ones.

Tail-like structure Moves the cell

Tiny hairs on the cell surface Moves the cell OR Moves things around the cell