Objectives List scientists who contributed to the cell theory List the components of the cell theory Compare prokaryote and eukaryote cells Label a plant and an animal cell Know the functions of cell organelles

Early Contributions Robert Hooke - First person to see cells, he was looking at cork and noted that he saw "a great many boxes. (1665) Anton van Leeuwenhoek - Observed living cells in pond water, which he called "animalcules" (1673)

Leeuwenhoek saw these things in pond water. What did he call them?

Theodore Schwann - zoologist who observed tissues of animals had cells (1839) Mattias Schleiden - botanist, observed tissues of plants contained cells ( 1845) Rudolf Virchow - also reported that every living thing is made of up vital units, known as cells. He predicted that cells come from other cells. (1850 )

The Cell Theory 1. Every living organism is made of one or more cells. 2. The cell is the basic unit of structure and function. 3. All cells arise from pre- existing cells. *Why is the Cell Theory called a Theory and not a Fact?

1. All living things are made of _____ Checkpoint What was their contribution? Hooke Leeuwenhoek Schwann Schleiden Virchow The Cell Theory 1. All living things are made of _____ 2. Cells are the basic unit of _______ and ______ 3. Cells come from _______________ cells.

Cell Features ALL cell have these parts Ribosomes – make protein for use by the organism Cytoplasm – fluid material within  cell DNA – genetic material Cytoskeleton – internal framework of cell Cell Membrane – outer boundary, some things can cross the cell membrane

Comprehension Checkpoint Answer true or false Robert Hooke was the first person to see cells. Bacteria cells have a cell membrane. The Cell Theory was developed by a single scientist. Plant cells have cytoplasm. Cells taken from fungi do not have DNA. Cells can only come from pre-existing cells. It only took five years to develop the Cell Theory.

Prokaryote Cells The first cells to inhabit the earth Simple cells Bacteria These cells do NOT have a nucleus, their DNA is circular and floats in the cytoplasm Some bacteria have a tail-like structure called a flagella, that helps it to move. A capsule surrounds some bacteria and helps them avoid the body’s immune system

Bacteria Images Bacteria that causes Anthrax

Bacteria belong to a group of cells that do not have a ____________ CHECKPOINT LABEL THE BACTERIA Bacteria belong to a group of cells that do not have a ____________

Eukaryotic Cells Cells found in plants, animals, protists, and fungi   The cell is composed of 4 main parts: Cell membrane Cytoplasm Nucleus – “control center” of cell, DNA Organelles – small structures that carry out specific functions (“little organs”)

Nucleus Usually found at center of cell Has a nuclear membrane & nuclear pores  Contains cell’s DNA in one of 2 forms chromatin - DNA and proteins, becomes... chromosomes - during cell division   Nucleolus - which makes the cell’s ribosomes

True of False 1. All cells have a nucleus. 2. All cells have a cell membrane. 3. Eukaryote cells are the only cells to have a flagellum. 4. The nucleus contains the cell’s DNA. 5. Chromatin will become chromosomes. 6. The nucleolus makes the cell’s DNA.

Ribosomes Proteins are assembled on ribosomes Small particles of RNA and protein found throughout the cytoplasm  Cells active in protein synthesis are packed with ribosomes

Protein Production The cell is like a factory. Its product is protein which goes to body to serve different functions. DNA has instructions to build protein Instructions are sent to ribosomes The ribosomes build protein and sends it through ER The proteins go to golgi where they are packaged for export

Cell Organelles Lysosome – Contains digestive enzymes, breaks things down, "suicide sac” Endoplasmic Reticulum – Transport, "intracellular highway".  Rough ER contains many ribosomes & is involved in protein synthesis  Smooth ER no ribosomes, is involved in assembling lipid components of the cell membrade

Cell Organelles Golgi Apparatus – modifies, sorts, and packages proteins for storage in the cell or secretion outside the cell. It is comparable to a factory or a post office. *A vesicle forms with Golgi to transport substances outside cell.  

Vacuole – storage area for water and other substaces, plant cells usually have a large central vacuole

Cell Organelles Mitochondria – cell’s energy center; turns food into a chemical energy called ATP The mitochondria is sometimes called the “powerhouse” of the cell

Cytoskeleton – Helps cell maintain support & shape; movement a. microtubules- hollow tubes b.  microfilaments-threadlike c.  centrioles- only in animal cells; used during cell division (paired) 

THE ANIMAL CELL

Cheek Cells Seen Through Microscope

NAME THE PARTS

Plant Cells CHLOROPLASTS – contain green pigment, photosynthesis CELL WALL – provides additional support CHLOROPLASTS – contain green pigment, photosynthesis CENTRAL VACUOLE – large water container

PLANT CELL Can you identify the parts?

Anacharis Cells Viewed With a Microscope

Animal Cell vs Plant Cell

Organelles With DNA Mitochondria and chloroplasts have their own DNA (separate from the nucleus) This supports the ENDOSYMBIOSIS THEORY which states that eukaryotic cells evolved when prokaryote cells engulfed or absorbed other cells.

CELL MEMBRANE Selectively permeable ; it regulates what comes into the cell and what leaves the cell It is composed of a double layer of phospholipids with proteins embedded throughout