Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Wassily Kandinsky ( ) Cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.1x Cell Theory: - all organisms are composed of cells - all cells come from other cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Scanning electron microscope (SEM) Figure 4.1B TEM
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cell size and shape relate to function Minimum Maximum Figure 4.2
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A small cell has a greater ratio of surface area to volume than a large cell of the same shape 30 µm10 µm Surface area of one large cube = 5,400 µm 2 Total surface area of 27 small cubes = 16,200 µm 2 Figure 4.3
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic cells - “ before nucleus” - small, relatively simple cells –Single-celled organisms –May not require oxygen –No organelles (with membranes) 2 kinds of cells: prokaryotic and eukaryotic
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A prokaryotic cell has: - plasma membrane - rigid cell wall –sticky capsule Ribosomes Figure 4.4 Capsule Cell wall Plasma membrane Prokaryotic flagella Nucleoid region (DNA) Pili –Nucleoid region with DNA –Some w/ flagella
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic cells, Bacillus polymyxa Figure 4.4x1 Cytoplasm
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings - true nucleus - larger: microns - often multicellular - organelles surrounded by membranes - usually need O2 Eukaryotic cells - functional compartments
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings a group of organelles that manufactures and distributes cell products nucleus endoplasmic reticulum (ER), ribosomes Golgi complex, vesicles Endomembrane System
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings largest organelle nuclear envelope contains DNA that directs cell’s activities DNA copy goes into every progeny cell nucleus is the control center ENDOMEMBRANE SYSTEM
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.6 Chromatin Nucleolus Pore NUCLEUS Two membranes of nuclear envelope ROUGH ENDOPLASMIC RETICULUM Ribosomes
nuclear pores nucleus Yeast cell
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Makes proteins, membranes Rough endoplasmic reticulum (RER) Transport vesicle buds off Ribosome Sugar chain Glycoprotein Secretory (glyco-) protein inside transport vesicle ROUGH ER Polypeptide Figure 4.8
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings SMOOTH ER ROUGH ER Nuclear envelope Ribosomes SMOOTH ERROUGH ER Figure 4.9
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The Golgi complex finishes, sorts, and ships cell products Golgi apparatus “Receiving” side of Golgi apparatus Transport vesicle from ER New vesicle forming Transport vesicle from the Golgi Golgi apparatus “Shipping” side of Golgi apparatus Figure 4.10
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings sacs of digestive enzymes budded off the Golgi Fuse with membrane around debris Lysosomes LYSOSOME Nucleus Figure 4.11A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Lysosomal enzymes –digest food –destroy bacteria –recycle damaged organelles –function in embryonic development in animals –Storage of undigestable waste - (cell aging?) Pombe’s disease - glycogen Tay-Sachs disease - lipids
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.11B Rough ER Transport vesicle (containing inactive hydrolytic enzymes) Golgi apparatus Plasma membrane LYSOSOMES “Food” Engulfment of particle Food vacuole Digestion Lysosome engulfing damaged organelle
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings synthesizes lipids regulates carbohydrate metabolism breaks down toxins and drugs in liver Stores Ca++ in muscle cells Smooth endoplasmic reticulum
0.5 micrometers smooth endoplasmic reticulum vesicles
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Nucleus, ribosomes, RER,SER, Golgi, vesicles Endomembrane system Transport vesicle from ER Rough ER Transport vesicle from Golgi Plasma membrane Vacuole Lysosome Golgi apparatus Nuclear envelope Smooth ER Nucleus Figure 4.14
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Vacuole in plants –Lysosomal – storage of pigments, poisons –Water relations Central vacuole Nucleus Figure 4.13A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings plant cells –large central vacuole – rigid cell wall –chloroplasts
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings in plants and some protists convert solar energy to chemical energy in sugars Chloroplasts Chloroplast Stroma Inner and outer membranes Granum Intermembrane space Figure 4.15
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.16 Outer membrane Mitochondrion Intermembrane space Inner membrane Cristae Matrix cellular respiration
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings network of protein fibers The CYTOSKELETON helps organize a cell’s structure and activities Figure 4.17A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings microfilament Intermediate filament microtubule Actin subunitFibrous subunits Tubulin subunit 7 nm 10 nm 25 nm Cell shape, movement reinforce cell, anchor organelles cell rigidity, anchor & tracks for organelles, mitosis
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Nuclei (yellow) and actin (red) Figure 4.6x
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A cilia or flagellum is composed of a core of microtubules wrapped in plasma membrane Eukaryotes have “9+2” structure How do cilia and flagella move?
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Eukaryotic cilia and flagella are locomotor appendages that protrude from certain cells A cilia or flagellum is composed of a core of microtubules wrapped in an extension of the plasma membrane Cilia and flagella
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.18A FLAGELLUM Outer microtubule doublet Plasma membrane Central microtubules Outer microtubule doublet Plasma membrane Electron micrograph of sections: Flagellum Basal body Basal body (structurally identical to centriole)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Surfaces allow exchange of signals and molecules. Plant cells connect by plasmodesmata Cell surfaces protect, support, and join cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.19A Vacuole Layers of one plant cell wall Walls of two adjacent plant cells PLASMODESMATA Cytoplasm Plasma membrane
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Animal cells - surrounded by an extracellular matrix –sticky layer of glycoproteins –binds cells together in tissues –can also protect and support cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Tight junctions can bind cells together into leakproof sheets Anchoring junctions link animal cells Communicating junctions allow substances to flow from cell to cell TIGHT JUNCTION ANCHORING JUNCTION COMMUNICATING JUNCTION Plasma membranes of adjacent cells Extracellular matrix Figure 4.19B
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Eukaryotic organelles fall into 4 functional groups 1. Manufacture and transport – dependent on network of membranes -Nucleus -Ribosomes -Rough, smooth ER -Golgi apparatus
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 2. Breakdown – all single-membrane sacs Lysosomes (in animals, some protists) Peroxisomes Vacuoles (plants)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 3. Energy Processing – involves extensive membranes embedded with enzymes Chloroplasts Mitochondria
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 4. Support, Movement, Communication Cytoskeleton – includes cilia, flagella, filaments, microtubules Cell walls Extracellular matrix Cell junctions