Cell Structure and Function

1. Cell – Smallest unit that can carry out all of the activities necessary for life Aka: the basic units of life

Cell Theory 3 Parts of the Cell Theory All living things are composed of cells. Cells are the basic units of structure and function in all living things. New cells are produced from existing cells.

Human cell Bacteria cell

Prokaryotic cells are smaller and have a large surface-to-volume ratio means that nutrients can easily and rapidly reach any part of the cells interior. Eukaryotic cell- larger cells which means nutrients cannot rapidly diffuse to all interior parts of the cell. Why eukaryotic cells require a variety of specialized internal organelles to carry out metabolism, provide energy, and transport chemicals throughout the cell

2 Main Types of Cells

A. Prokaryotes -have NO nucleus and NO membrane bound organelles. 3. Types of Cells A. Prokaryotes -have NO nucleus and NO membrane bound organelles.

PROKARYOTE Pro = “before”, karyon = “nucleus” 4. Single Cell “PRO” means “NO” contain genetic information but NO NUCLEUS Ex: Only Bacteria They grow, reproduce, respond to the environment, and some can move by gliding along surfaces with the help of flagellum.

Figure 7.4 A prokaryotic cell

5. Eukaryotes -have a nucleus and membrane bound organelles Eu = “true”, karyon = “nucleus” Eukaryotic cells require a variety of specialized internal organelles to carry out metabolism, provide energy, and transport chemicals throughout the cell

Eukaryotic Cell

6. EUKARYOTE Summary Can be unicellular or multicellular Always HAS A NUCLEUS that seperates genetic information from the rest of the cell. Has membrane bound organelles. Examples: plants, animals, fungi and protists. Divided into 2 major parts: nucleus and cytoplasm

Organelle = tiny specialized organs 7. Organelles Organ = A group of tissues with one or a few functions : heart, lung, stomach, liver, pancreas, skin, kidney, etc.) -elle = small or tiny Organelle = tiny specialized organs

8. CELL MEMBRANE – “strainer or screen” (thin flexible barrier around the cell) Semi-permeable – regulates what enters and leaves the cell. Protects cell & holds cell together

c. Made of phospholipids d. Also called the Plasma Membrane

CYTOPLASM- portion of the cell outside the nucleus (jelly-like material) 2 purposes of cytoplasm: Supports cell parts Allows cell parts to move

10. NUCLEUS – “brain” contains all the cell’s DNA and with it coded instructions for making proteins. Control center of the cell

3a. CHROMOSOMES Contains the DNA/genes that direct the making of proteins to make an organisms traits i. Chromatin is long thin invisible DNA ii. Chromosomes are short fat condensed visible DNA

11. NUCLEOLUS Controls cell reproduction and makes ribosomes which make proteins

12. NUCLEAR MEMBRANE Controls what enters and leaves the nucleus

13. VACUOLES – “storage boxes” a. Storage of food and water, wastes and enzymes b. Animal cells have many small ones while plant cells have one large one Plant Vacuole

14. ENDOPLASMIC RETICULUM “bus” (highway) Transport system in the cell The site where lipids of the cell membrane are assembled, along with proteins and other materials that are exported from the cell. c. Rough ER with ribosomes and smooth without ribosomes.

15. RIBOSOMES -Produce proteins for the cell “protein factories”

16. MITOCHONDRIA (powerhouse) a. Converts stored food into energy ATP for the cell to use.

17. GOLGI BODY – “packaging plant” (post office) a. Package & exports protein from the cell Hair, finger nails are good examples of these proteins

ORGANELLES FOUND IN ONLY ANIMAL CELLS

ANIMAL CELLS ONLY 18. CENTRIOLE Small part of animal cell that helps in cell division

ANIMAL CELLS ONLY 19. LYSOSOME (garbage collector) a. Contain enzymes that digest or gets rid of worn out cell parts, bacteria or viruses b. Found in carnivorous plants

ORGANELLES FOUND IN ONLY PLANT CELLS

20. CELL WALL lie outside the cell membrane PLANT CELLS ONLY 20. CELL WALL lie outside the cell membrane a. Provide support and protection for the cell. b. Made of Cellulose which makes plant stiff

21. CHLOROPLAST (green) a. Filled with the green pigment chlorophyll b. Makes chemical energy in the form of sugar from sunlight in the process called photosynthesis.

13. CENTRAL VACUOLE membrane bound organelle which is present in all plant and fungal cells and some protest Huge vacuole in plant cells used for: storage Isolating materials that might be harmful or a threat to the cell Maintaining internal hydrostatic pressure or turgor within the cell Exporting unwanted substances from the cell Allows plants to support structures such as leaves and flowers due to the pressure of the central vacuole

Plant Cell Smooth endoplasmic Vacuole reticulum (free) Chloroplast Nuclear envelope Ribosome (attached) (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole Plant Cell

Animal Cell (attached) Ribosome Nucleolus (free) Nucleus Cell Membrane Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth Mitochondrion Cell Membrane Ribosome (free) (attached) Animal Cell

Answers to VENN Diagram Prokaryotes VS Eukaryotes Cell membrane Contain DNA membrane bound. have ribosomes .similar basic metabolism Nucleus membrane-bound organelles DNA is within nucleus undergo mitosis 10 times larger Smaller Flagella No nucleus Contains DNA floating freely cell wall composed of peptidoglycan divide by binary fission

Differences DIFERENCES: 1. eukaryotes have a nucleus, while prokaryotes do not 2. eukaryotes have membrane-bound organelles, while prokaryotes do not. The organelles of eukaryotes allow them to exhibit much higher levels of intracellular division of labor than is possible in prokaryotic cells. 3. Eukaryotic cells are, on average, ten times the size of prokaryotic cells. 4. The DNA of eukaryotes is much more complex and therefore much more extnsive than the DNA of prokaryotes. 5. Prokaryotes have a cell wall composed of peptidoglycan, a single large polymer of amino acids and sugar . Many types of eukaryotic cells also have cell walls, but none made of peptidoglycan. 6. The DNA of prokaryotes floats freely around the cell; the DNA of eukaryotes is held within its nucleus and associated with histones (proteins) 7. Eukaryotes undergo mitosis; prokaryotes divide by binary fission (simple cell division)

Prokaryotes Eukaryotes Animal Cells Plant Cells Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell membrane Contain DNA Animal Cells Plant Cells Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Centrioles