a. a. definition b. b. history 1. 1. microscopes cytology i. i. introduction

A. DefinitionB. History1.

Microscopes

Cytology

I. Introduction

a. In the 16th century, Galileo used simple pieces of glass to visualize and describe the eye of an insect.b. In the 17th century, Van Leeuwenhoek ground glass to visualize the structure of cells like bacteria and sperm.c. Robert Hooke used ground glass to visualize cork structure and coined the term “cellulae” or cell.

The advantage of a microscope magnification and resolution; Magnification to enlarge; Resolution to clearly distinguish two objects or clarity

2. Cell Theory

In the 19th century Schleiden and Schwann said a. Cells are the smallest functional units

of life andb. All living things are made up of cells.

Later in the 19th century Virchow and Pasteur added

c. Cells only arise from pre-existing cells.

A. Microscopes1. Light

II. Cytological Tools

a. Bright Field

b. Dark Field

c. Phase Contrast

d. Confocal

2. Electron

a. Transmission

b. Scanning

c. Environmental TEM/SEM

B. Stains

a. Vital Stains are mainly from various plant pigments.

for Contrast

b. Antibody stains are more specific and are made by exposing antigen to some host animal.

More Contrast

A. Strategies1.

Prokaryotes

III. Basic Cell Design

a. Cell Size Limits Surface to Volume Ratio

Figure 4.2

b. Characteristics

Figure 4.4

2. Eukaryotes

Representative Animal Cell

Figure 4.7

Representative Plant Cell

Figure 4.8

B. Parts1. Cell Membranea. Molecular

Structure

Figure 4.5

Which molecule would act as an impermeable barrier?Which molecule would act as an cellular label or antenna?Which molecule(s) would act as a transporter?

Which molecule(s) would act to stiffen the membrane?

b. Functions

Membrane Protein Functions

i. Passive Transport

Requirements = With a Concentration Gradient, Small Molecules, Requires No Energy Expenditure, and Relatively Non-polarMechanisms = Simple Diffusion, Facilitated Diffusion, and Osmosis

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Osmosis movement of a solvent (usually H2O) across a semi-permeable membrane

Figure 5.13

ii. Active Transport

Requirements = Uses Energy, Protein Channel, Large Molecules, and Goes against the Concentration GradientMechanisms = Molecular

Figure 5.14

Mechanisms = Bulk

Figure 5.15

If the arrowheads were reversed could you tell the difference?

Mechanisms = Cell-Mediated

Once inside the vesicle is the material really inside the cell?

Figure 5.16

2. Cytosol = Cell Sapa.

Consistencyb. Molecular Make-up

a. Cytosol consistency like thickening Jell-Ob. Molecular make-up 92% is water, 7% protein, and the rest is gases, salts, lipids, and the like dissolved in the water

3. Organelles = Cell Machinerya. Membrane Bound

Nucleus = the keeper of the plans

Figure 4.9

Chromatin, nucleolus envelope, and pores,

Endomembrane System = rER, sER, and Golgi

Figure 4.12

House cleaners -> Lysosome or Peroxisome

Energy Transformers = the Chloroplast and the Mitochondria

Figure 4.14

Figure 4.15

Vacuoles = Cell storage sites

Animal Types = Food (sugars, lipids, etc), or Contractile (water storage)Plant Types = Central (water storage), Amyloplasts (store starch), and Chromoplasts (store Pigments)

b. Non-Membrane Bound

Cytoskeleton

Figure 4.17

Ribosome and CentriolesFigure 4.19

C. Cellular Specializations1. Microvilli

Microvilli = short non-moving membrane extensions (orange area) to increase cell’s overall surface area

3. Flagella

2. Cilia

Flagella = longer cellular extensions to move the entire cell

Cilia = long, moving internal cellular extensions to move something across the cell surface.

Figure 4.20

4. Intercellular Junctions

i. Plants

ii. Animals

Figure 4.11

Figure 4.21

Figure 4.23

Always think function?

5. Extracellular Interactions

Always think function?

Focus on the goal.