4.2 Parts of the Eukaryotic Cell *Membrane-bound organelles *Organelles = smaller parts inside the cell 3 main parts Cell membrane Nucleus Other organelles How is a prokaryotic cell different?

ENDOPLASMIC RETICULUM (ER) Nucleolus NUCLEUS Rough ER Smooth ER Fig. 6-9a Nuclear envelope ENDOPLASMIC RETICULUM (ER) Nucleolus NUCLEUS Rough ER Smooth ER Flagellum Chromatin Centrosome Plasma membrane CYTOSKELETON: Microfilaments Intermediate filaments Microtubules Ribosomes Microvilli Golgi apparatus Peroxisome Mitochondrion Lysosome

Rough endoplasmic reticulum Fig. 6-9b Nuclear envelope Rough endoplasmic reticulum NUCLEUS Nucleolus Chromatin Smooth endoplasmic reticulum Ribosomes Central vacuole Golgi apparatus Microfilaments Intermediate filaments CYTO- SKELETON Microtubules Mitochondrion Peroxisome Chloroplast Plasma membrane Cell wall Plasmodesmata Wall of adjacent cell

4.2 Parts of the Eukaryotic Cell *Cell membrane Contains the cell *Selectively permeable = must let some things in and out Lipid bilayer forms the membrane *Proteins in the membrane act as doors Peripheral = on surface only Integral = through membrane What other things are selectively permeable?

Carbohydrate side chain Fig. 6-7 (a) TEM of a plasma membrane Outside of cell Inside of cell 0.1 µm Carbohydrate side chain Hydrophilic region Hydrophobic region Hydrophilic region Phospholipid Proteins (b) Structure of the plasma membrane

4.2 Parts of the Eukaryotic Cell *Cytoplasm = cell goo Cytosol = fluid (water, salts, minerals, biochemicals…) All cellular interactions and most life interactions occur in watery fluid

4.2 Parts of the Eukaryotic Cell *Mitochondria Cigar shaped with a double membrane *Power plants of the cell Produce energy by separating a phosphorus group from ATP Cristae are folds of inner membrane Increase surface area More places for chemical reactions to occur

in the mitochondrial matrix Fig. 6-17 Intermembrane space Outer membrane Free ribosomes in the mitochondrial matrix Inner membrane Cristae Matrix 0.1 µm

4.2 Parts of the Eukaryotic Cell *Ribosomes Not bound by membrane Proteins bound to RNA Function in the assembly of proteins Workers that build proteins

Endoplasmic reticulum (ER) Fig. 6-11 Cytosol Endoplasmic reticulum (ER) Free ribosomes Bound ribosomes Large subunit Small subunit 0.5 µm TEM showing ER and ribosomes Diagram of a ribosome

4.2 Parts of the Eukaryotic Cell *Endoplasmic Reticulum “ in plasma net” Membranous tubes & sacs Stuff moves along ER *Place where proteins can be made Rough ER has ribosomes on the surfaces Smooth ER has no ribosomes

Smooth ER Nuclear envelope Rough ER ER lumen Cisternae Transitional ER Fig. 6-12 Smooth ER Nuclear envelope Rough ER ER lumen Cisternae Transitional ER Ribosomes Transport vesicle 200 nm Smooth ER Rough ER

4.2 Parts of the Eukaryotic Cell *Golgi apparatus Named after Golgi Membranous folds & sacs like ER *Packages proteins and other materials to be sent out of cell Parts of the membrane break off surrounding proteins

Nucleus Rough ER Smooth ER cis Golgi Plasma membrane trans Golgi Fig. 6-16-2 Nucleus Rough ER Smooth ER cis Golgi Plasma membrane trans Golgi

4.2 Parts of the Eukaryotic Cell *Lysosomes *Small round membranes that surround enzymes The enzymes digest other molecules These are the stomach or food delivery trucks

Nucleus 1 µm Lysosome Digestive enzymes Lysosome Plasma membrane Fig. 6-14a Nucleus 1 µm Lysosome Digestive enzymes Lysosome Plasma membrane Digestion Food vacuole (a) Phagocytosis

4.2 Parts of the Eukaryotic Cell *Cytoskeleton Framework of the cell Microfilaments are polymer fibers of the protein actin Help cells move Pull to make muscles move Microtubules are protein tubes that move the cell

Cross section of cilium Fig. 6-24 Outer microtubule doublet Plasma membrane 0.1 µm Dynein proteins Central microtubule Radial spoke Protein cross-linking outer doublets Microtubules (b) Cross section of cilium Plasma membrane Basal body 0.5 µm (a) Longitudinal section of cilium 0.1 µm Triplet (c) Cross section of basal body

4.2 Parts of the Eukaryotic Cell *Cilia & flagella Hairlike organelles that extend outside of cell surface Cilia are shorter and more numerous Flagella are longer but fewer *Both function to move the cell around the environment

Direction of organism’s movement Fig. 6-23 Direction of swimming (a) Motion of flagella 5 µm Direction of organism’s movement Power stroke Recovery stroke (b) Motion of cilia 15 µm

4.2 Parts of the Eukaryotic Cell *Nucleus *Large organelle that contains DNA and where RNA is copied from DNA Nucleolus = specialized region where ribosomes are made Contains full copy of all genetic information for the organism

Close-up of nuclear envelope Fig. 6-10 Nucleus 1 µm Nucleolus Chromatin Nuclear envelope: Inner membrane Outer membrane Nuclear pore Pore complex Rough ER Surface of nuclear envelope Ribosome 1 µm 0.25 µm Close-up of nuclear envelope Pore complexes (TEM) Nuclear lamina (TEM)

4.2 Parts of the Eukaryotic Cell *Plant cells have some special structures *Cell wall is a rigid barrier outside the cell membrane Made of carbohydrate polymers Give plants structural strength

Secondary cell wall Primary cell wall Middle lamella Central vacuole Fig. 6-28 Secondary cell wall Primary cell wall Middle lamella 1 µm Central vacuole Cytosol Plasma membrane Plant cell walls Plasmodesmata

4.2 Parts of the Eukaryotic Cell *Vacuoles are large fluid filled membranes *Store water and enzymes, and hold waste products

Cortex (outer cytoplasm): gel with actin network Fig. 6-27bc Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits Extending pseudopodium (b) Amoeboid movement Nonmoving cortical cytoplasm (gel) Chloroplast Streaming cytoplasm (sol) Vacuole Parallel actin filaments Cell wall (c) Cytoplasmic streaming in plant cells

4.2 Parts of the Eukaryotic Cell *Plastids are double membrane sacs that store biochemicals or pigments *Chloroplast is organelle that converts sun energy into chemical energy for plants * hold chlorophyll

Inner and outer membranes Fig. 6-18 Ribosomes Stroma Inner and outer membranes Granum 1 µm Thylakoid

4.2 Parts of the Eukaryotic Cell

4.2 Parts of the Eukaryotic Cell