Cell Parts and Cell Diversity Essential Standard Bio..1.1 Understand the relationship between the structures and functions of cells and their organelles.

Cell Parts Organelle – cell part that performs vital functions for the cell Some are membrane-bound All Cells have Cytoplasm/Cytosol Cell membrane Ribosomes DNA

Cell Membrane Semipermeable membrane that only certain molecules or ions pass through (so it is selective) Found around all cells Made of phospholipids

Cell Membrane Composed of phospholipid bilayer Fluid Mosaic Model Polar phosphate head (hydrophilic) 2 nonpolar, fatty acid tails (hydrophobic) Fluid Mosaic Model Membrane Proteins Peripheral Proteins Integral Proteins Carbohydrates Steroids

Cytoplasm/Cytosol Cytoplasm/ – watery substance within the cell that keeps organelles in place

Mitochondria Powerhouse of the cell; produces ATP (energy) Has double membrane More cristae (inner membrane folds) = more ATP production Has DNA Found in all eukaryotes

Ribosomes Site of protein production Has no membranes Found in all cells Made of ribosomal RNA

Endoplasmic Reticulum (ER) The ER is found in eukaryotes Rough ER – studded with ribosomes; prepares proteins for export Smooth ER – makes vesicles, synthesizes steroids, regulates calcium levels, and breaks down toxins

Golgi Apparatus Processes and packages substances produced by cell Proteins arrive and leave in vesicles Has a membrane Found in eukaryotes

Lysosome Digests molecules, old organelles, and foreign substances Contains digestive enzymes Has membrane Found in animals

Cytoskeleton Network of long protein strands in cytosol; support movement and division Made up of microfilaments and microtubules (proteins) Has no membrane Found in all cells

Nucleus Stores DNA, manufactures ribosomes and RNA Nucleolus – where RNA is synthesized Has nuclear envelope = double membrane Found in eukaryotes

Cell Wall Supports the structure of and protects the cell Made of carbohydrates Found in plants, bacteria, some protists, and fungi Plants – cellulose Bacteria – peptidoglycan funcgi - chitin

Vacuoles Central Vacuole – in plant cells; stores water Food Vacuole – in animal cells; stores food and waste Contractile Vacuole – in animal cells; maintains water balance

Chloroplasts Stores food or pigments to utilize for photosynthesis Thylakoids – membranes within chloroplasts – site where chlorophyll sits Double membrane Found in plants and some protists

Cilia, Flagella, and Pseudopods Cilia – hair-like extensions that aids in movement and feeding Flagella – long, whip-like tail that propels cell through environment Pseudopods – cytoplasmic extensions that aid in movement and capturing food

Cell Diversity Human body contains over 200 different types of cells Most of them have the same DNA even though they look and act very different

Cell Diversity Shape – cells shape reflects diversity of different functions Examples Skin cells – flat and layered – for protection Nerve cells – extensions – for communication Blood cells – round – for transport

Cell Diversity Size – cells are limited in size by ratio between surface area and volume Cells grow larger, more nutrient demand

Cell Types Prokaryotic Cells – “before nucleus” Ex. Bacteria Unicellular Contains cell membrane, ribosomes, circular DNA (plasmids). No nucleus or membrane bound organelles Ex. Bacteria

Cell Types Eukaryotic Cells – “good nucleus” Unicellular or Multicellular Contains cell membrane and membrane bound organelles Has nucleus – contains DNA Ex. Plants, Animals, Protists, Fungi