What is a cell Cell Basic unit of

What is a cell? Cell – Basic unit of structure and function in all living things

Cell Study and Discovery • . • Matthias Schleiden (1888) – All plants are made up of cells • Theodore Schwann (1889) – All animals are made up of cells • Rudolph Virchow (1889) – Cells come from preexisting cells.

The Cell Theory • • • All living things are made up of cells Cells are the basic unit of structure and function in all living things Cells come from pre-existing cells

Shape – Shape Form reflects function Red Blood Cells are like tubes at Sesame Place so they flow easier Nerve cells are like electrical wires Cheek cells (Epithelial cells) are flat to act like a shield White Blood cells are amoeboid shaped to move and squeeze into all areas

Types of cells 1. Prokaryotic cells – Primitive cells – “before the nucleus” – No membrane bound organelles – No nucleus – Found in Eubacteria and Archaeabacteria – Cell wall, cell membrane, cytoplasm, DNA & ribosomes

2. Eukaryotic “True nucleus” – Have membrane – bound organelles – All other kingdoms but Archaeabacteria & Eubacteria – Organelles such as: Mitochondria, endoplasmic reticulum, vacuoles, lysosomes, and chloroplasts.

Comparing the Two Cytoplasm DNA Cell Membrane

Structures common to both Prokaryotic and Eukaryotic cells • • • Cell Membrane Ribosomes DNA Cytoplasm Cell Walls (not in Animal or some Protist cells though!) Organelle – small structures in cells that have a specific function

Cell Organelles and Their Functions 1. Cell Membrane – Outermost boundary in all Animal Cells. - Separates the cell’s internal environment from the external environment. - Allows for the passage of some substances based on size and concentration - Selectively Permeable due to pores being present

Made up of a bilipid layer (lipid bilayer) – 2 layers of lipids with proteins floating through it.

• In the "fluid mosaic model" of membrane structure, the membrane is a fluid bilipid layer in which protein molecules are either partially or wholly embedded. These layers easily move around Lipids Rap Protein

2. Nucleus – Only in Eukaryotic cells. – *Stores hereditary information. Nuclear Membrane – Surrounded by a double nuclear membrane Chromatin or envelope w/ pores – Chromatin (strands of a combination of DNA and protein within nucleus. These will later become Chromosomes. – Nucleolus (1 or >) produces ribosomes Nucleolus

3. Cytoplasm – “cell’s liquid” - Made of a gelatinous fluid (Cytosol) between the nucleus and cell membrane www. youtube. com/watch? v=PFtzs_c Udd. I – streaming movement of the cytoplasm. *Suspends organelles in place and carries material in solution around cell

4. Cytoskeleton - Network of protein strands that provide support and mobility of organelles in cytoplasm. - 2 components of cytoskeleton - Microfilaments and Microtubules (both made of protein)

5. Mitochondria - *Powerhouse of the cells. - Changes chemical bond energy of glucose into a usable form - *Site of Cellular respiration - Contains Cristae or folds to increase surface area - Has its own DNA and ribosomes and can replicate! - Found in greater numbers in cells such as muscle cells & liver cells (2500/cell) Cristae Double Membrane

6. Ribosomes – Most numerous organelle. *Site of protein synthesis. Made up of RNA and protein. May be free floating in cytoplasm or attached on Endoplasmic Reticulum

7. Endoplasmic Reticulum – Channels or passageways in the cell. • There are two types of ER: 1 – Rough w/ ribosomes attached for production & distribution of proteins. 2 – Smooth – Synthesis of lipids & detoxification of toxins

8. Golgi Apparatus (Bodies) – Stack of smooth flat sacs - Modifies, collects, packages & distributes molecules to all parts of a cell

9. Lysosomes - *Produces digestive enzymes – Are the cells' garbage disposal system. They breakdown worn out organelles – Clean up dead cells – Responsible for the un-webbing of hands of fetus while developing in utero – These are rare in plant cells

10. Vacuoles - *Stores food, water and wastes - Plant cells have a very large central water vacuole for support (turgor) - Animal cells have many small vacuoles

11. Centrioles – Found in animal cells 2 perpendicular bundles of microtubules - Function during cell division

Plant Cells’ Unique structures Plastids –Store starch or fats and many contain pigments to absorb light. - Chloroplasts - Double membraned. Contain Chlorophyll and DNA Convert solar energy into chemical bond energy of glucose (Photosynthesis)

Amyloplasts (Leucoplasts) Store starch

Cell Wall – Gives cell rigidity, support and protection. - Made up of cellulose with pectin (glue) between adjacent cells.

1. Nucleus 2. Ribosomes 3. Mitochondria 4. Chloroplasts 5. Cell Membrane 6. Cytoplasm 7. Cell Wall 8. Central Vacuole 9. Golgi Apparatus 10. Endoplasmic Reticulum Typical Plant Cell

Cheek Cells Nucleus Cytoplasm Cell Membrane

Cyclosis Elodea

Onion Cells

Amyloplast Cell Wall Potato Cells

Typical Animal Cell 1. Nucleolus 2. Nucleus 3. Ribosome 4. Vacuole 5. Rough ER 6. Golgi Apparatus 7. Microtubule 8. Smooth ER 9. Mitochondria 10. Vacuole 11. Cytoplasm Typical Animal Cell 12. Lysosome 13. Centriole

Organelle Function Plant Cells Animal Cells Mitochondria Site of cellular respiration - transfer of energy - Folds called Cristae Yes Ribosomes Site of Protein synthesis Yes Endoplasmic Reticulum Rough - Protein packaging & transport site Yes Smooth - Sythesis of lipids Yes Golgi Apparatus Processing & packaging center for cell secretions Few Many Lysosomes Produce hydrolytic enzymes Few Many Cytoskeleton Network of protein filaments - keep cell's shape and for movement Yes Microfilaments & microtubules Support, movement and cell division Yes Cilia & Flagella Cell movement & circulation Cilia - many & short, Flagella - 1 or 2 & long Yes Nucleolus Production of ribosomes Yes Nucleus Contains DNA, synthesizes RNA & Ribosomes Yes Chromatin DNA & protein - genetic information Yes Cell Wall Outmost layer of plant cell - support & protection Made of cellulose & pectin glue between walls Yes No Vacuole Stores enzymes, wastes, water & food Large water in plants - support Yes, large water vacuole Many Yes No No Yes Yes Plastid Centrioles Cell Membrane Stores food and pigments - Chloroplasts (photosynthesis) & leucoplasts (stores starch) Microtubules that function during cell division Selectively permeable - made of a bilipid layer &