Parts of Prokaryotic & Eukaryotic Cells

Cell Theory 1. All living things are made of ____________. 2. Cells are the basic unit of __________ & __________ in an organism. 3. All cells come from the reproduction of ____________ cells.

CELL MEMBRANE MODEL Phospholipids and proteins move laterally, or side to side, for short distances. Proteins make a pattern on the surface known as the fluid mosaic model.

NUCLEUS and NUCLEOLUS NUCLEUS is: Surrounded by nuclear MEMBRANE called the NUCLEAR envelope. Serves as the control CENTER OF CELL Nuclear pores allow molecules in and out

NUCLEUS and NUCLEOLUS CONTAINS CELL’S GENETIC MATERIAL ( DNA) Contains NUCLEOLUS (Dark spot) which makes ribosomes (RNA)

NUCLEUS and NUCLEOLUS Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics

Nuclear Envelope Double membrane surrounding nucleus Also called nuclear membrane Contains nuclear pores for materials to enter & leave nucleus Connected to the rough ER

CHROMATIN & CHROMOSOMES DNA is scrunched up as CHROMOSOMES in DIVIDING CELLS DNA is spread out as CHROMATIN in NON-DIVIDING CELLS

CYTOSKELETON Made of PROTEINS called actin and tubulin. FUNCTIONS: Helps cell maintain its shape Helps organelles move around

LYSOSOMES Sac containing digestive enzymes FUNCTION: Digests: food, bacteria, and worn out cell parts for cells Plays a role in APOPTOSIS: “programmed cell death” Cell suicide for the good of the ORGANISM

LYSOSOMES Cells take in food by phagocytosis Lysosomes digest the food & get rid of wastes

VACUOLE In plants, they store Cell Sap STORAGE SPACE FOR: In plants, they store Cell Sap Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes Huge in PLANT cells, small in ANIMAL cells, NOT in BACTERIAL cells.

VACUOLE

CENTRIOLES Bundle of microtubules made of PROTEINS called tubulin. (9+3 ring) Only seen in ANIMAL cells during cell division Function: largely unknown, but they do assist in cell division

CILIA & FLAGELLA Made of PROTEINS called microtubules– tubulin also. organized in a “9+2” arrangement that help with moving cells, in moving fluids, or in small particles across the cell surface

CILIA & FLAGELLA CILIA: shorter& more numerous; look like short “hairs” FLAGELLA: longer & fewer; look like “tails”; typically only 1-3 per cell. FUNCTION (BOTH): cell movement, if cell is non-motile, moves fluid over cell surface Ex.- Cilia lining your windpipe sweep mucus containing trapped debris out of your lungs.

CILIA & FLAGELLA

Cilia Moving Away Dust Particles from the Lungs

RIBOSOMES Can be FREE in the cytosol or ATTACHED to the surface of Rough ER MADE OF rRNA (ribosomal) & PROTEIN FUNCTION: MAKE PROTEINS

CELL MEMBRANE or PLASMA MEMBRANE Made mainly of PHOSPHOLIPIDS and PROTEINS HYDROPHOBIC “tails” of phospholipids make molecules line up as a LIPID BI-LAYER with POLAR heads facing OUT and NON-POLAR tails facing IN (to inside of bi-layer)

CELL MEMBRANE or PLASMA MEMBRANE Outside of cell Inside (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

CELL MEMBRANE or PLASMA MEMBRANE Proteins attached to surface (inside or outside)= PERIPHERAL PROTEINS Proteins stuck into membrane = INTEGRAL PROTEINS (can go part way in or all the way through)

CELL MEMBRANE or PLASMA MEMBRANE Membranes are selectively permeable/ semi-permeable when they allow certain molecules to pass through; but keep others out. Cytoplasm/ cytosol is the “gel-like material + organelles” between nucleus and cell membrane

CELL MEMBRANE or PLASMA MEMBRANE OTHER MOLECULES: GLYCOPROTEINS with attached CARBOHYDRATE tails to recognize self Contain the steroid CHOLESTEROL to make membranes more flexible

MITOCHONDRION (plural: MITOCHONDRIA) Surrounded by DOUBLE membrane. Contains its own DNA. Called the “powerhouse” of cell Burns food (sugars, fats, etc) to release energy.

MITOCHONDRION (plural: MITOCHONDRIA) Stores energy released as ATP. Smooth outer membrane Folded inner membrane = CRISTAE (increases surface area for more chemical reactions)  Cellular respiration happens in the inner membrane.

MITOCHONDRION (plural: MITOCHONDRIA) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria

ENDOPLASMIC RETICULUM(ER) Internal network of hollow membrane tubules. Connects to nuclear envelope & cell membrane

ENDOPLASMIC RETICULUM(ER) ROUGH ER Rough ER has ribosomes on its surface, while smooth does not. Rough ER: Attached ribosomes make PROTEINS which are modified & exported. FUNCTION ROUGH ER: Makes membrane proteins and proteins for export out of cell

ENDOPLASMIC RETICULUM(ER) Proteins are made by ribosomes on ER surface They are then threaded into the interior of the Rough ER to be modified and transported

ENDOPLASMIC RETICULUM(ER) Rough ER has RIBOSOMES on its surface, while SMOOTH does not. Is attached to the ends of rough ER

ENDOPLASMIC RETICULUM(ER) SMOOTH ER FUNCTION SMOOTH ER: Makes cell products that are USED In the cell Makes membrane lipids (steroids) Regulates calcium (muscle cells) Destroys toxic substances (Liver)

GOLGI APPARATUS (BODY) Looks like a stack of flattened sacs. FUNCTION: Modify, sort, and package substances from ER for transport out of cell OR for storage. Have a shipping side (cis face) & a receiving side (trans face) Receive proteins made by ER Transport vesicles with modified proteins pinch off the ends

GOLGI APPARATUS (BODY) CIS TRANS Transport vesicle

GOLGI APPARATUS (BODY)

VESICLES Sacs made of membrane Used to transport substances within the cell– protein from ER to Golgi to cell membrane, or to take in food (endocytosis) or get rid of wastes (exocytosis) Disposable; pinch off of and fuse with other membranes in the cell.

VESICLES

ENDOMEMBRANE SYSTEM Includes nuclear membrane connected to ER connected to cell membrane (transport)

ENDOMEMBRANE SYSTEM

CHLOROPLASTS Surrounded by double membrane Has its own DNA Outer membrane smooth Inner membrane sacs called THYLAKOIDS contain CHLOROPHYLL where photosynthesis happens.

CHLOROPLASTS Stacks of thylakoids called GRANA. Gel like material around thylakoids called STROMA. FOUND ONLY IN PLANT CELLS

CELL WALL Found OUTSIDE the cell membrane. Provides structure & support. Cellulose in the cell wall makes plant cells sturdy. Bacteria have cell walls made of peptidoglycan instead of cellulose. Made of chitin in Fungi

PROKARYOTES Bacteria are the most common prokaryotic cell. They do not have a nucleus, but do contain a single circular chromosome made of DNA, found in the NUCLEOID REGION. Like all cells, bacteria are surrounded by a cell membrane which contains the gel-like cytosol of the cell.

TONOPLAST Membrane that encloses the CENTRAL VACUOLE in a plant cell, separating it from the cytosol.

PEROXISOMES Organelle containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.

PLASMODESMATA An open channel in the cell wall of PLANTS through which strands of CYTOSOL connect from adjacent cells.

CENTROSOME Present in cytosol of all eukaryotic cells; important during cell division; the MICROTUBULE organizing center.