Cells and Organelles

Famous Men Leeuwenhoek: first to see living microorganisms Used a simple microscope Robert Hooke: named the cell Used a compound microscope to look at cork Reminded him of rooms in a monastery Called them cells

Cell Structure and Function Cells vary in size. Longest cell- nerve cells (up to 2 meters long) Smallest cell- bacteria largest cell- egg Cells vary in shape. Shape relates to function Blood cells are smooth, round, and flow easily through the blood vessels

Cell Theory T. Schwann: all animals are made of cells M. Schleiden: All plants are made of cells Virchow: All cells come from pre-existing cells Cell Theory All living things are made of cells Unicellular- 1 cell multicellular- 2+ cells Cell is the basic unit of life The beginning unit is always a cell All cells come from other cells

Cell Types cell organelles-organs in a cell 2 Cell Types: most important organelle= nucleus (controls all cell functions) Nucleus:Cell :: Brain: Body (a nucleus is to the cell what the brain is to the body) 2 Cell Types: Prokaryote Eukaryote no nucleus nucleus no membrane bound membrane bound organelles organelles simple complex contains: cell wall, cell membrane Contains: nucleus and and ribosomes organelles Bacteria ONLY Plants/Animals/Fungus

Nucleus Nucleus- control center (contains chromatin) Chromatin- Tangles of DNA Nucleolus- located in the center of the nucleus, produces Ribosomes **only eukaryotes have a nucleus

Cell Wall Rigid Structure- does not move like the cell membrane Surrounds Cell membrane Provides Support Ex: Plants, fungi, some protists and bacteria

Ribosomes and Cytoplasm Ribosomes: Found on the Endoplasmic Reticulum or in the cytoplasm Site of Protein Synthesis All cells Cytoplasm: jelly-like substance between the nucleus and cell membrane Surrounds the organelles inside the cell A place for Chemical Reactions and Transport

Endoplasmic Reticulum (ER) Folded Membrane (increased surface area) Assembly and transport of proteins and lipids Rough ER has attached ribosomes Eukaryotes only (plant and animals)

Mitochondrion Produces Energy (ATP) for the cell Inner folded membrane increases surface area, the greater the surface area the more area for production of ATP Eukaryotes only (plant and animal cells)

Golgi Body and Vacuole Golgi Body: Packaging and Shipping of Proteins and Lipids Packaged into Vesicles eukaryotes Vacuole Storage of Food, water, and waste Larger in plant cells- usually contains water

Chloroplast Photosynthesis happens here Contains chlorophylls that absorbs sunlight (green pigment) Plant cells only Light energy +CO2+ H2Oglucose+O2

Microtubules, Microfilaments, and Lysosomes Microtubules and Microfilaments Protein fibers involved in cell movement and shape of the cell Moves organelles throughout the cell Lysosomes Used to digest food Used to break down the cell when it dies Animal cells only

Plasma Membrane Plasma membrane (Cell Membrane) Surrounds cell Maintains homeostasis Homeostasis-constant internal environment selectively permeable Controls what enters and leaves the cell ALL CELLS

Plasma Membrane Plasma Membrane- flexible outer boundary of a cell (like skin) Job- to maintain homeostasis (internal balance) Plasma Membrane is Selectively Permeable- chooses what passes through Selectively- choosy about what comes in and what goes out Permeable- allows to pass Fluid Mosaic Model- moves like a fluid with embedded proteins

Plasma (Cell) Membrane is to cell as skin is to body Three molecules in the membrane: Phospholipid is the main molecule, a lipid that has a: Phosphate Group + Glycerol Backbone (Hydrophilic Head) 2 fatty acid chains- Tail (Hydrophobic) Saturated fatty acids make the membrane more rigid Unsaturated fatty acids makes the membrane more fluid-like

2. Membrane Protein 3. Cholesterol Transport Proteins- help larger molecules get across the cell membrane Enzymes- help speed up the reaction Chemical Markers- help cells to identify each other Cell Signaling- messages from outside of the cell are communicated to the inside 3. Cholesterol Found in animal cells Lipid gives stability to the membrane

3 Differences between Plant and Animal Cells Plant cells have cell walls Plant cells have chloroplasts Plant cells have larger vacuoles