Cells Module B Lesson 1

Organisms An individual form of life All organisms have basic needs Plant Animal Bacteria All organisms have basic needs Survive Grow reproduce

UNICELLULAR VS. MULTICELLULAR UNIcellular- organism of only 1 cell that does all the jobs of the cell Plankton Yeast Amoeba

UNICELLULAR VS. MULTICELLULAR MULTIcellular- organisms made of several cells that have their own job to do Plants Animals

UNICELLULAR VS. MULTICELLULAR Unicellular- divides to make new cells Multicellular- divides to grow and replace old and dead cells

What are cells? Smallest unit of life Building blocks of life

Characteristics of Cells They have different shapes They have different parts – called organelles Cells have different functions (jobs)

Pseudonomonal Aeruginosa Bacteria Cell Streptococcus pyogenes Bacteria Cell Human Blood Cell Escherichia Coli (E. Coli) Bacteria Cell

Cell examples Blood cells Skin cells (top right) Muscle cells (bottom right) Brain cells (below)

Introduction to the Cell Cell Theory

Discovery of Cells The invention of the lens Robert Hooke (1665): observed a thin slice of cork (dead plant cells) with a microscope. He described what he observed as “little boxes” (cells).

Discovery of Cells Anton van Leeuwenhoek (1675): was the first person to observe living cells. He saw single- cell organisms swimming in pond water He used a stronger microscope and was able to see unicellular organisms (bacteria and protozoa).

Observed the nucleus in plant cells

The Cell Theory Who developed the cell theory? Matthias Schleiden (1838): concluded that all plants are composed of cells Theodor Schwann (1839): concluded that all animals are composed of cells Rudolph Virchow (1855): determined that cells come only from other cells

The Cell Theory What is the cell theory? 1. All living things are composed of one or more cells. 2. Cells are organisms’ basic units of structure and function. 3. Cells come only from existing cells.

Microscopes Magnification: refers to the microscope’s power to increase an object’s apparent size Resolution: refers to the microscope’s power to show detail clearly

Light Microscope

Light Microscope Elodea - Aquatic Plant 40X 400X

Transmission Electron Microscope (TEM)

Transmission Electron Microscope (TEM) Plant Root Cell

Scanning Electron Microscope (SEM)

Scanning Electron Microscope (SEM)

Scanning Electron Microscope (SEM) Mosquito Head 200X 2000X

Scanning Electron Microscope (SEM) Fly Eye

Scanning Electron Microscope (SEM) Inside of Stomach Surface of Tongue Neuron

Scanning Electron Microscope (SEM) Pollen Yeast Red Blood Cell, Platelet, and White Blood Cell

TEM vs. SEM Viruses leaving a cell

Cell Diversity Size Shape Internal Organization

Cell Diversity- Size Smallest Cells: Biggest Cells: Longest Cells: 6 inches long, 5 inches wide, 3 pounds Ostrich Egg

Cell Diversity- Shape Cells differ widely in shape. Most cells are roughly cuboidal or spherical.

ORGANELLES: Parts the Cell

Organelles Structures in the cell’s cytoplast (fluid in the cell) that has its own shape and has a specific job in the cell

The Parts of the Cell Each living cell carries out the tasks of taking food, transforming food into energy, getting rid of wastes, and reproducing. Most eukaryotic cells have three main components: Cell Membrane Cytoskeleton Nucleus

Nucleus Structure: the nucleus is a sphere that contains another sphere called a nucleolus Function: -storage center of cell’s DNA -manages cell functions

Cell Wall Structure: rigid wall made up of cellulose, proteins, and carbohydrates Function: boundary around the plant cell outside of the cell membrane that provides structure and support

Mitochondria Structure: folded membrane within an outer membrane The folds of the inner membrane are called cristae Function: -converts energy stored in food into usable energy for work cellular respiration

Lysosomes Structure: spherical organelles that contain hydrolytic enzymes within single membranes Function: breaks down food particles, invading objects, or worn out cell parts

Chloroplasts Structure: stacked sacs (thylakoids) that contain chlorophyll surrounded by a double membrane Function: photosynthesis (conversion of light energy to chemical energy stored in the bonds of glucose)

Ribosomes Protein builders Makes proteins necessary to repair damaged cells

Hierarchy of Biological Order

Hierarchy of Biology

Hierarchy of Biology Cells Tissues- group of cells working together Organs- group of tissues working together Organ system- 2 or more organs working together

Examples Cells Tissues- group of cells working together Muscle tissue made of muscle cells Skin tissue made of skin cells Organs- group of tissues working together Lungs, heart, stomach Organ system- 2 or more organs working together Nervous system Muscular system

THE END!