CHAPTER 4: CELLS, part 1 The fundamental units of life

Exam 1: Monday, September 19 Exam will be in class

Fig Colorized TEM

2 fundamental kinds of cells 1. Prokaryotes Bacteria 2. Eukaryotes plant cells, animal cells, fungal cells, protozoa

Unnumbered Figure 14_UN293c Based on taxonomic characteristics

Figure 1.9

Figure 4.4

Fig Plasma membrane (encloses cytoplasm) Cell wall (provides Rigidity) Capsule (sticky coating) Prokaryotic flagellum (for propulsion) Ribosomes (synthesize proteins) Nucleoid (contains DNA) Pili (attachment structures) Colorized TEM

Figure 4.5 Prokaryotic cell

Figure 4.6a

Figure 4.6b

Figure 4.3

Dissecting Microscope (light) Low mag (up to 20x) View frog eggs, protozoans, etc. Compound Microscope (light) Higher mag (up to 400x) Tissue sections or wet mounts on glass slides Light goes through the slide Cells, tiny protozoans, etc.

Figure 4.2a

Transmission Electron Microscope (TEM) Max. Mag: 1.5 millionX Ultrathin plastic sections of tissue Electron beam goes through section View cell organelles, cell membrane, bacteria, viruses, etc.

Figure 4.2c

Scanning Electron Microscope Mag: 10x up to 1 millionX Electron beam scans across the surface of the specimen 3-dimensional view Tiny insects, spiders, protozoans, rocks, fossils, etc.

Figure 4.2b

Figure 4.2

Fig Light Micrograph (LM) (for viewing living cells) Light micrograph of a protist, Paramecium LM Colorized SEM Scanning Electron Micrograph (SEM) (for viewing surface features) Scanning electron micrograph of Paramecium TYPES OF MICROGRAPHS Transmission Electron Micrograph (TEM) (for viewing internal structures) Transmission electron micrograph of Paramecium Colorized TEM

Fig. 4-02

Cell components (Eukaryotic cell) Plasma membrane (cell membrane) Cytoplasm Nucleus Nucleolus Ribosome Endoplasmic reticulum Rough ER, Smooth ER Golgi Apparatus Mitochondria, Chloroplasts Vacuole, Vesicle Lysosome Cytoskeleton Cilia, flagella

Figure 4.6a

Cell components (Eukaryotic cell) Plasma membrane (cell membrane) : Phospholipid bilayer with embedded proteins and other substances (cholesterol, glycoproteins) Fluid Mosaic model: Molecules can move about freely and lots of different proteins floating in the “phospholipid sea”

Functions: 1. Controls movement of substances into and out of the cell Phospholipid bilayer, protein channels 2. Cell signaling: Glycoproteins, recognition proteins 3. Receptors for various substances Receptor proteins with binding sites

Cell components (Eukaryotic cell) Cytoplasm: a semifluid medium which contains water and various molecules suspended or dissolved in it

Figure 4.6a

Cell components (Eukaryotic cell) Nucleus: Control center of the cell Contains the chromatin and the nucleolus Chromatin: DNA plus proteins Chromatin forms the chromosomes when the cell divides Nucleolus: chromatin which forms rRNA

Figure 4.6a