Transcript 7-Cells and the Microscope

Chapter 7 – The Cell
I.
A View of the Cell
A.
Contributing Scientists who came up with
ideas about the cell:
1.
Hooke (1665) – first saw cork cells &
named the tiny boxes “cells” after
monk’s rooms in a monastery
2.
Leeuwenhoek (1683) – saw
cells using a microscope which
he invented
3.
Schleiden (1838) – said cells
compose every part of a plant
4.
Schwann (1839) – said cells compose
every part of an animal
5.
B.
Virchow (1855) – said cells only
come from other cells
The Cell Theory – 3 parts:
1.
All organisms are made of 1+ cells
2.
Cells are the basic unit of structure &
organization of all living organisms
(a cell is the simplest living part)
3.
All cells come from pre-existing cells,
& pass copies of genetic information
on to daughter cells
C.
2 Cells Types:
1.
Prokaryote – No true nucleus nor
organelles; DNA not separated by a
membrane (only Bacteria)
The Scale of Life
2.
Eukaryote – has a true nucleus and
organelles (all cells, besides Bacteria)
II.
The Cell is like a Factory
A.
Cell/Plasma Membrane (Doors):
maintains homeostasis by regulating what
goes in & out of the cell (selectively
permeable)
B.
Nucleus (Boss): contains directions for the
cell’s operations
C.
Nucleolus (Boss’ Assistant): inside nucleus,
it makes ribosomes
D.
Chromatin (Blueprints): inside nucleus;
are strands of DNA with directions for cell
E.
Cytoplasm (Air): jellylike fluid that fills
the cell
F.
Mitochondria (Generator): makes energy
(ATP) for the cell/our body
G.
Golgi Body (Assembly Line): packages
cell products
1.
Vesicles
(trucks):
distribute
cell products
H.
Centriole (Boss’ wife):
helps in cell reproduction
I.
Cytoskeleton (steel frames in brick walls):
stick-like microtubules & microfilaments
support the cell like a skeleton
J.
Lysosome (cleanup crew w/ garbage cans):
digest wastes
K.
Ribosomes (Cooks): make protein
L.
Endoplasmic Reticulum (Vending
Machines):
1.
Smooth ER (almonds): no ribosomes,
makes fats
2.
Rough ER (cheese): has ribosomes,
makes proteins
M.
Movement Organelles
1.
Cilia (conveyor belt):
parts that sway
2.
hair-like
Flagella (forklift):
whip-like tail
III.
Parts found only in Plant Cells:
A.
Cell Wall (Bricks): – rigid for support
B.
Vacuole (Warehouse): – filled w/ fluid &
stores water and waste
C.
Chloroplast (Solar Panels): makes glucose
through photosynthesis; green due to
chlorophyll
Let’s check out these for Review:
 The Cell Song
https://www.youtube.com/watch?v=rABKB5aS2Zg
 Cells Cells – Parts of the Cell
https://www.youtube.com/watch?v=-zafJKbMPA8
 Cells from Other Cells
https://www.youtube.com/watch?v=BTicXXxzQA4
Chapter 7 – The Microscope
 Before microscopes were invented, people believed
that diseases were caused by curses and spirits
I.
Types of Microscopes (2)
A.
Light Microscope – has a series of lenses
to magnify objects in steps
1. light passes thru object being observed
2. object can be living or dead
3. magnifies up to 1500x (ours 400x)
4. Total Magnification = Eyepiece x Lens
B.
Electron Microscope (EM) – a beam of
electrons is focused by magnets to
enlarge an image
 magnifies objects up to 500,000x
 object is placed in a vacuum, so it is
often dead when viewed
 costs about $25,000
1.
Transmission EM (TEM) – electrons
pass thru object; 2D views
2.
Scanning EM (SEM) – electrons
bounce off surface of object;
3D views
3.
Scanning Tunneling EM (STM) – electrons
“tunnel” through living specimens; sees atoms
4.
Atomic Force Microscope (AFM) – measures
force b/t probe and specimen
II.
Parts of the Microscope:
Magnifies image
Changes the
objectives
Used to carry
the microscope
Magnify the image
Supports the slide
Holds slide in place
Rough focus for low
& medium
Controls amount of light
Detailed focus
Illuminates the specimen
Supports the
microscope
III.
Using the Microscope
1.
Turn the light switch on and put the slide
onto the stage
2.
Start with the lens in low power
3.
Focus the specimen using coarse, then
fine adjustment
4.
Rotate the nosepiece to medium power
5.
Focus the specimen using coarse, then
fine adjustment
6.
Rotate the nosepiece to high power
7.
Focus the specimen using FINE
adjustment ONLY