Day 23 Agenda ACT Practice Microscopes Notes Prokaryotes vs. Eukaryotes HW: study for Quiz on Thursday over microscope types and parts

Bell Ringer Day 23 ACT Practice Set

Microscopes

History of the Microscope 1655 – Robert Hooke used a compound microscope to observe pores in cork He called them “cells”

History of the Microscope Antoine van Leeuwenhoek 1st to see living organisms

Microscope Vocabulary Magnification: increase of an object’s apparent size Resolution: power to show details clearly

Staining Objects can be stained so that parts can be seen better.

Total Magnification Multiply the eyepiece magnification (10X) by the objective magnification (4X, 10X, 40X) Example: 4 x 10 = 40X total

1. Compound Light Microscope 1st type of microscope, most widely used Types of Microscopes 1. Compound Light Microscope 1st type of microscope, most widely used light passes through 2 lenses Can magnify up to 2000x Can view living specimens

Eyepiece Objective lenses

Types of Microscopes 2. Electron Microscope Used to observe VERY small objects: viruses, DNA, parts of cells Uses beams of electrons rather than light Much more powerful

Transmission Electron Microscope (TEM) Can magnify up to 250,000x Types of Microscopes Transmission Electron Microscope (TEM) Can magnify up to 250,000x View details within structures

Scanning Electron Microscope (SEM) Can magnify up to 100,000x Types of Microscopes Scanning Electron Microscope (SEM) Can magnify up to 100,000x View the 3D structure/texture

The Discovery of Cells Prokaryotic before nucleus Eukaryotic true

Prokaryotes NO nucleus NO membrane bound organelles (just ribosomes) ALL are unicellular Smaller than eukaryotic cells Forerunner to eukaryotic cells (smaller and more simple) DNA –circular Ex: ALL Bacteria 21

Eukaryotes Has a nucleus with a nuclear envelope Bigger and more complex than prokaryotes Have membrane bound Organelles (golgi, ER, lysosomes…etc) DNA – double-stranded and forms chromosomes (highly organized) Can be uni- OR multicellular organisms Ex: animals, plants, fungi

Similarities Contain all four macromolecules Have ribosomes Have DNA (lipids, carbs, proteins, and nucleic acids) Have ribosomes Have DNA Similar Metabolism Can be unicellular Have cell/plasma membranes May have cell wall

Eukaryote VS. Prokaryote Picture