ch. 4 cell structure and function intro.-4.2 what are the 7 characteristics of life? intro.-4.2 what...
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Ch. 4 Cell Structure and Function
Ch. 4 Cell Structure and Function
Intro.-4.2
What are the 7 Characteristics of Life?
Intro.-4.2
What are the 7 Characteristics of Life?
Cells, organization, reproduction, energy use, response to stimuli, adaptation, growth
Cells, organization, reproduction, energy use, response to stimuli, adaptation, growth
I. Cell Discovery Timeline:
Early 17th centuryEarly 17th century
Galileo Galilei-among the first
to record a biological observation made with a “microscope”
Galileo Galilei-among the first
to record a biological observation made with a “microscope”
mid 17th centurymid 17th century
Robert Hooke-coined the term
“cell” after observing dead cork cells
Robert Hooke-coined the term
“cell” after observing dead cork cells
Late 1600sLate 1600s
Antony van Leeuwenhoek
-observed “animalcules”
=small moving creatures
Antony van Leeuwenhoek
-observed “animalcules”
=small moving creatures
1820s1820s
Robert Brown-with
improvements in lenses, viewed a nucleus
Robert Brown-with
improvements in lenses, viewed a nucleus
18381838
Matthias Schleiden
-hypothesized: each cell must develop independently
Matthias Schleiden
-hypothesized: each cell must develop independently
18391839
Theodor Schwann-animals and
plants are made of cells which have an individual life of their own
Theodor Schwann-animals and
plants are made of cells which have an individual life of their own
mid-19th centurymid-19th century
Rudolf Virchow-every cell comes
from an existing cell
Rudolf Virchow-every cell comes
from an existing cell
II. The Cell TheoryII. The Cell Theory
1. Every organism is composed of one or more cells.
2. The cell is the smallest unit having the properties of life.
3. The continuity of life arises directly from the growth and division of single cells.
1. Every organism is composed of one or more cells.
2. The cell is the smallest unit having the properties of life.
3. The continuity of life arises directly from the growth and division of single cells.
4.1 Basic Aspects of Cell Structure
4.1 Basic Aspects of Cell Structure
Cell- the smallest unit having the properties of life
Cell- the smallest unit having the properties of life
I. Structural Organization of Cells
I. Structural Organization of Cells
Plasma membrane (aka cell membrane)Plasma membrane
(aka cell membrane)-separates the cell
from its environment, allowing substances and signals to move across in controlled ways.
*Found in all cells
-separates the cell from its environment, allowing substances and signals to move across in controlled ways.
*Found in all cells
Nucleus or nucleoid-location of DNA
Nucleus or nucleoid-location of DNA
*eukaryotic cell*eukaryotic cell *prokaryotic cell
CytoplasmCytoplasm
-semi-fluid substance in the cell
-semi-fluid substance in the cell
Prokaryotic cellsProkaryotic cells
-lack a membrane-bound nucleus and organelles
-Kingdoms: ArchaebacteriaEubacteria
-lack a membrane-bound nucleus and organelles
-Kingdoms: ArchaebacteriaEubacteria
Eukaryotic cellsEukaryotic cells
-have a membrane-bound nucleus and organelles
Kingdoms:Protista, Fungi, Plantae, Animalia
-have a membrane-bound nucleus and organelles
Kingdoms:Protista, Fungi, Plantae, Animalia
What 3 parts do all cells have?
What 3 parts do all cells have?
II. Lipid Bi-layer of Cell Membrane
II. Lipid Bi-layer of Cell Membrane
Includes proteins embedded in the membrane which:
1. Act as passive channels for water-soluble substances
2. Pump substances across the bi-layer3. Act as receptors for hormones and
other signaling molecules
Includes proteins embedded in the membrane which:
1. Act as passive channels for water-soluble substances
2. Pump substances across the bi-layer3. Act as receptors for hormones and
other signaling molecules
Read pp. 46-49 in Holt Biology book (lion on
cover)
Read pp. 46-49 in Holt Biology book (lion on
cover)
III. Cell size and shapeIII. Cell size and shape
Cell size is limited by the surface to volume ratio. If a cell expands in diameter during growth, its volume will increase more rapidly than its surface area. Each unit of the cell’s plasma membrane will have to serve much more cytoplasm making cell transport inefficient. Also, a small cell has more efficient transport within the cell from organelle to organelle.
Cell size is limited by the surface to volume ratio. If a cell expands in diameter during growth, its volume will increase more rapidly than its surface area. Each unit of the cell’s plasma membrane will have to serve much more cytoplasm making cell transport inefficient. Also, a small cell has more efficient transport within the cell from organelle to organelle.
On the next slide you will see: Largest human cell by volume Smallest human cell Longest human cell
On the next slide you will see: Largest human cell by volume Smallest human cell Longest human cell
4.2 Microscopes4.2 Microscopes
Micrograph- a photographic image taken through a microscope
Micrograph- a photographic image taken through a microscope
I. Light microscopeI. Light microscope
A. Compound light -light must pass through the specimen-ours magnify 1,000X max.
A. Compound light -light must pass through the specimen-ours magnify 1,000X max.
B. Stereoscope (aka dissecting microscope)
- object is lit from the top and bottom, so can be opaque, 50X
B. Stereoscope (aka dissecting microscope)
- object is lit from the top and bottom, so can be opaque, 50X
II. Electron MicroscopesII. Electron Microscopes
A. Transmission electron microscope- cannot view living organisms, specimens must be sliced and stained
-50- 1,000,000X
A. Transmission electron microscope- cannot view living organisms, specimens must be sliced and stained
-50- 1,000,000X
B. Scanning electron microscope- specimens coated with a thin layer of metal, cannot view living, 3-D
-5-500,000X
B. Scanning electron microscope- specimens coated with a thin layer of metal, cannot view living, 3-D
-5-500,000X
C. Scanning tunneling microscope- scans the surface of the object, can view living
-up to 100,000,000X
C. Scanning tunneling microscope- scans the surface of the object, can view living
-up to 100,000,000X
Why are microscopes a critical discovery?
Why are microscopes a critical discovery?