Cells : The Basic Unit of Life

1. Cells: The Basic Unit of Life Essential Questions What are cells made of? Where do you find cells? Why do cells look different? How do cells work?

2. I. Cells – basic building block of life • Cytology: study of cells • Cyto- having to do with cells • -ology means the study of • Cytopathology: the study of cellular disease and the use of cellular changes for the diagnosis of disease. • Cell biology: the study of (normal) cellular anatomy, function and chemistry.

3. II. Cell History Robert Hooke (1665) English Scientist Looked at a thin slice of cork (oak tree) through a compound microscope Observed tiny, hollow, room like structures Called these structures “cells” because they reminded him of the rooms that monks lived in He only saw the cell walls because the cork cells weren’t alive

4. Anton Van Leeuwenhoek (roughly same time as Hooke, 1680?) • Dutch fabric merchant and amateur scientist • Looked at blood, rainwater, and scrapings from teeth through a simple microscope (1 lens) • Observed living cells; called some ‘animalcules’ • Some of those ‘animalcules’ are now called bacteria • Father of Microbiology

5. Co-Founders of Cell Theory Matthias Schleiden (1838) Theodor Schwann (1839) German Zoologist Viewed animal parts under a microscope Discovered that animal parts are made of cells • German Botanist • Viewed plant parts under a microscope • Discovered that plant parts are made of cells

6. Rudolf Virchow (1855) • German physician and politician, known for his advancement of public health • First to recognize leukemia cells • Stated that all living cells come from other living cells • Important contributor to cell theory

7. III. Cell Theory • The contributions of Hooke, Van Leeuwenhoek, Schleiden, Schwann and Virchow helped to form the modern cell theory • 1. All living things are made of cells • 2. All cells come from other cells • 3. The cell is the basic unit of organization in organisms

8. All Living Things… • Consist of organized parts (cells -> tissues -> organs -> organ systems -> organisms) • Obtain energy from their surroundings (food chain) • Perform chemical reactions (metabolize) • Change with time (evolve) • Respond to their environment (adapt) • Reproduce (heredity)

9. IV. Types of Cells Prokaryote Eukaryote More complex cell Has membrane bound organelles and nucleus Possess chromosomes Ex: are plant and animal cells • Simple cell • Lacks a nucleus and membrane bound organelles • Has circular DNA and ribosomes • Ex: Bacteria and Archaea are twodomains of prokaryotes

10. V. Parts of Eukaryotic Cells Organelle: small, membrane bound structure inside the cell that determines the function of the cell; tiny organs

11. V. Parts of Eukaryotic Cells, cont. • Plasma Membrane – phospholipidbilayer, controls what enters and exits the cell, Gateway

12. V. Parts of Eukaryotic Cells, cont. B. Cytoplasm- gel-like substance that surrounds and suspends the organelles, Jell-O of the Cell Consists of cytosol-The cytosol is a complex mixture of substances dissolved in water

13. V. Parts of Eukaryotic Cells, cont. C. Cytoskeleton – network of microfilaments and microtubules that form the inner structure of the cell, similar to your bones, Skeleton

14. V. Parts of Eukaryotic Cells, cont. D. Golgi bodies – set of smooth membranes that form flattened sacs that modify, sort and package proteins for transport to other organelles or exiting the cell FedEx -small round packages are called vesicles

15. V. Parts of Eukaryotic Cells, cont. E. Mitchondria – site where cellular respiration occurs, chemical energy is released from glucose • Inside folds increase chemical workspace and are called: mitochondrial matrix • Powerhouse

16. V. Parts of Eukaryotic Cells, cont. F. Lysosome – these membrane bound sacs contain enzymes that can digest cellular waste, damaged organelles, and bacteria brought into cell. Can also destroy entire cell -Suicide sac

17. V. Parts of Eukaryotic Cells, cont. G. Ribosomes – tiny, round organelles that are used to make (synthesize) proteins - workbench

18. V. Parts of Eukaryotic Cells, cont. H. Endoplasmic Reticulum • Smooth- works to detoxify cells and transport materials, MoDOT Highway • Rough – has ribosomes on it, makes the phospholipids and proteins, Liver or Highway

19. V. Parts of Eukaryotic Cells, cont. • Vacuole – membrane bound structures that usually hold water and provide structure for the cell Storage units

20. V. Parts of Eukaryotic Cells, cont. J. Nucleus – controls all cellular functions Brain 1. Nuclear Membrane – plasma membrane surrounding and containing the nucleus 2. Nuclear Pores- tiny holes in nuclear membrane that allow RNA to pass in and out of nucleus 3. Chromosomes/Chromatin – Chromatin is DNA free floating, when it prepares for division it coils into chromosomes 4. Nucleolus – site of concentrated DNA in the nucleus

21. V. Parts of Eukaryotic Cells, cont. • Outside the cell • Cilia – motile for movement or non-motile for sensory (below, pink) • Flagella – Single ‘tail’ for movement • Microvilli – are cellular membrane protrusions that increase the surface area (below, B&W)

22. V. Parts of Eukaryotic Cells, cont. Animals Only Plants Only Cell Wall – made from cellulose, outside membrane Chloroplasts – contain stacks of thylakoids called granum & space between stacks is called stroma Plastids – organelles capable of storing food for the plant Chlorophyll – pigment used to capture sun’s energy Chromoplasts- give flowers and fruits their coloring • Centrioles – two bundles of nine microtubules, found close to nucleus and lie at 90 degree angle

23. How are cells organized? • Specialized cells -> tissue • Groups of tissue -> organs • Organs -> organ systems • Muscle cells -> muscle tissue • Muscles -> heart • Heart -> circulatory system

24. What will it look like to me? Take a look at these images and see if you remember looking at these

25. Onion Cells – may look like bubbles

26. More plant cells…

27. More than likely- a bunch of bubbles but they really are plant cells!

28. Now just a few more… • Here are some various types of cells • Notice the different shapes and what type of cell they are. Do you think this has to do with their function? • Think about it and take the time to notice how perfectly they are all designed for their jobs.

29. Blood cells – RBC, WBC, and platelets

30. Human Bone Marrow – Stem Cells So much debate over these little things that could save countless lives

31. Cardiac Muscle This is what the tissue looks like from your heart

32. Nerve Cells This looks like a lightening storm- fitting because it is an electrical storm of synapses firing electrical signals back and forth for your cells to communicate

33. Yeast Microscopic organism one-celled organism

34. Cancer Cell - Cancer is an uncontrolled growth of cells, caused by mutation of genes in cells