Cells Unit 3: Chapter 4

Lesson Objectives: 10/12 List the scientists who contributed to our knowledge of the cell List the 3 components of the cell theory

Cells A cell is the smallest unit that can carry on all of the processes of life It is the smallest unit in all living things

Units? Biological Organization: Atom Molecule Cell Tissue Organ Organ system Organism

The History of the Cell Theory We had to first see the cells Anton van Leeuwenhoek Dutch Biologist Invented the first microscope 1600

History cont’d Robert Hooke (1665) Robert Brown (1833) English Botanist Observed the first cells in cork Coined the term “little boxes” Robert Brown (1833) Scottish Botanist Located a “dark” structure new the center of cells The nucleus

History Cont’d Matthias Schleiden (1838) Theodor Schwann (1839) German Botanist Stated the all plants were composed of cells Theodor Schwann (1839) Discovered that animals are made of cells Rudolf Virchow (1855) Physicist Stated that all cells come from other cells Cell division

Our life line! Timeline Robert Brown Anton van Leeuwenhoek 1600 1665 Theodor Schwann 1833 1839 1855 Rudolf Virchow 1838 Matthias Schleiden Robert Hooke Our life line!

The Cell Theory All living things are composed of cells. Cells are the basic units of structure and function. All cell come from reproduction of preexisting cells.

So in review...... Can you....... Name the scientist involved in the history of the cell theory? Name the 3 components of the cell theory?

Cell Diversity

Lesson Objectives Be able to name the two main types of cells. State which type of cell is larger. Identify which type of cell does not have a membrane bound nucleus. Name the three main parts of the cell (that all cells have).

Cell Diversity Not all cells are alike! You have at least 200 different cell types. Different sizes, shapes and internal organizations Helps it perform its function

Size Some are large enough to be seen by the unaided eye: Chicken egg (yolk) Frog eggs Giraffe’s nerve cell runs down its leg Size is limited by the ratio between their outer surface area and their volume If surface area is too small, can’t get enough nutrients and oxygen

Shape

Internal Organization Cell membrane surrounds the cell: Thin membrane that helps protect the cell Prokaryotes vs. Eukaryotes

Prokaryote vs. Eukaryote Cells Endosymbiosis theory:  All organelles seem to share many properties with bacteria. Lynn Margulis proposed endosymbiont hypothesis: that organelles derived from ancient colonization of large bacteria (became the eukaryotic cell) by smaller bacteria (became the mitochondria, chloroplast, etc.) Symbiosis = "living together".   *Mitochondria & Chloroplasts have their own DNA

Prokaryotes No membrane bound nucleus No membrane bound organelles chromosomes grouped together in an area called the "nucleoid" No membrane bound organelles Smaller than eukaryotes Contain DNA, cytoplasm and ribosomes

Prokaryotes Have cell wall and cell membrane, some have a capsule on the outside Ribosomes make protein Consist of bacteria and archaebacteria Appendage: flagella Reproduce via binary fission

E. coli

Eukaryotes Has membrane bound nucleus Has membrane bound organelles in cytoplasm Much larger than prokaryotes Reproduce via mitosis Organisms within the animal, plant and fungi kingdoms are all eukaryotes

We will be spending a lot of time on these organelles and their functions

So In Review.... Can You...... Name the two main types of cells? State which one is larger?   Identify which one does not have a membrane bound nucleus? Name the three main parts of the cell (that all cells have)? State the 3 components of the cell theory?

Eukaryotic Organelles

Lesson Objectives 10/17 Be able to identify the cell membrane, cell wall and the nucleus. Describe the structure, composition and function of the cell membrane. Describe the structure and function of the nucleus.

Eukaryotic Cells All have (main components) A cell membrane A Nucleus Cytoplasm Other organelles

Cell Membrane Outer boundary of the cell Function: to regulate what comes into the cell and what goes out Selectively permeable

Fluid Mosaic Model http://www.youtube.com/watch?v=ULR79TiUj80 What are the structures that the video detailed are the ones that make up the plasma (cell) membrane? Proteins Allow molecules to pass through the membrane Carbohydrates Lipids (phospholipid bilayer)

Cell Wall Provides additional support and protects the cell (plant and bacteria cells) Not in animal cells Lies outside of the cell membrane Box and glove demonstration Made up of cellulose, polysaccharides and proteins

Nucleus "control center" of the cell Stores and transmits genetic information, DNA Provides the instructions for protein synthesis, RNA Found only in eukaryotes Responsible for communicating with other organelles through nuclear envelope Double membrane that surrounds nucleus Contains chromatin Genetic information (DNA)

Nucleolus The nucleus contains the nucleolus Small structure in the nucleus Make ribosomes Ribosomes aid in production of proteins within cell.

Cytoplasm Jell-o like substance: Cytosol The area between the cell membrane and the nucleus Contains structures in the cell Organelles Cytoskeleton The framework of the cell Contains microtubules and microfilaments Aid in movement and support the cell

So in review Can you...... Identify the cell membrane, cell wall and the nucleus. Describe the structure, composition and function of the cell membrane. Describe the structure and function of the nucleus.

Lesson Objectives 10/18 Be able to identify mitochondria, chloroplasts and the Golgi apparatus, and be able to describe their functions. Identify the three structures that are characteristic of plant cells.

Entrance Assessment With the materials located in front of you.... Create a diagram of the cell membrane Be able to label/point to the 3 main components of the cell membrane Label the hydrophilic and hydrophobic sides of the membrane Answer the question on your paper: What is the function of the cell membrane?

Mitochondria Powerhouse of the cell, providing most of its ATP supply ATP: molecule that most cells use as energy Contain their own RNA and DNA and are able to reproduce themselves Endosymbiosis theory Two membranes: Inner Contains long folds known as cristae Outer

Plastids Much like mitochondria: Chloroplasts are an examples Contain DNA Surrounded by 2 membranes Chloroplasts are an examples Convert energy from the sunlight into chemical energy Photosynthesis Contain large amounts of green pigment

Golgi Apparatus “Delivery System” flattened stacks of membranes functions in collection, packaging and distribution of molecules made in the cell and used elsewhere