Download The Microscope & The Cell

The Microscope & The Cell
Discovery of the Cell
A.
Anton VanLeeuwenhoek: a Dutch scientist
 He developed the first microscope
 Used a lens grinder to create the lenses
 Looked at pond water
B.
Robert Hooke: an English scientist who named the cell
 Looked at corks
 “Cells” were consistently rectangular
Discovery of the Cell, cont…
C.
Robert Brown: A Scottish scientist
 He discovered nucleus shapes
D.
Mathias Schleiden: a German botanist
 Discovered that plant tissues are made of cells
E.
Theodore Schwann: a German zoologist

Discovered that animal tissues are made of cells

Discovered “Schwann cells”
Discovery of the Cell, cont…
F.
Rudolph Virchow: German scientist
 Plant and animal cells are produced only by the division
of cells that already exist
G. The Cell Theory:
A. All living things are made of cells
B. Cells are the smallest working units of
living things.
C. All cells come from pre-existing cells
Prokaryotic Cells vs. Eukaryotic Cells
Prokaryotic Cells
Eukaryotic Cells
Primitive
Complex
Prokaryotic Cells vs. Eukaryotic Cells
Prokaryotic Cells
Eukaryotic Cells
Primitive
Complex
No nucleus
Has a nucleus and
organelles
Prokaryotic Cells vs. Eukaryotic Cells
Prokaryotic Cells
Eukaryotic Cells
Primitive
Complex
No nucleus
Has a nucleus and
organelles
Bacteria,
Blue-green algae
Plants and Animals
Cellular Organelle Functions
A. Cell Membrane
 Has 3 Basic Functions:
1. Controls what gets in/out (Selectively permeable)
2. Protection + support
3. Homeostasis = balanced state
Cell Membrane Function
 Materials can move across the cell membrane in
5 different ways
 Video on Movement across membrane(2:08)
a.
PASSIVE TRANSPORT
substances move across the cell membrane without the cell using
any energy
Cell Membrane Function, cont…
a.
PASSIVE TRANSPORT(0:45)
1. DIFFUSION
 High to low concentration
 No energy required by the cell
2. FACILITATED DIFFUSION
 High to low concentration
 No energy required by cell
 Requires help of a carrier protein
3. OSMOSIS
 Diffusion of water
Cell Membrane Function, cont…
b. ACTIVE TRANSPORT
 Movement of substances against a concentration
gradient therefore requires energy from the cell
(1) Sodium-Potassium Pump(1:20)
Cell Membrane Function, cont…
ENDOCYTOSIS
vs.
EXOCYTOSIS
Phagocytosis
&
Pinocytosis
used for solids
used for liquids
(1:20)
More About Cell Membrane
A. Known as the phospholipid bilyar
a. Phospholipid: Made up of…
1. Phosphate head: polar (charged)
i. Hydrophilic (water loving)
2. Lipid tails: nonpolar (non-charged)
i. Hydrophobic (water fearing)
b. Bilayer: Two layers
Phospholipid Bilayer
Cellular Organelle Functions, cont..
B. Nucleus
1. Function: contains nearly all of the cell’s DNA
 Contains coded instructions for making proteins and
other important molecules
2. Surrounded by two layered membrane called the nuclear
envelope
3. Contains chromatin which is made up of DNA molecules
and protein.
 When a cell is getting ready to divide, this material
changes in form to become chromosomes
Nucleus, continued…
4. DNA stands for Deoxyribonucleic Acid
a. DNA makes RNA (directs protein synthesis)
b. Discovered by James Watson & Francis Crick
c. DNA is shaped like a Double Helix
a. spiral staircase
b. twisted ladder
Cellular Organelle Functions, cont…
5. DNA Structure:
a. Sugar = deoxyribose
Nucleotide includes
b. Phosphate
c. Base: 2 Types
d. Hydrogen bond
Types of Bases
a. Purines:
 Adenine
 Guanine
b. Pyrimidines:
 Cytosine
 Thymine
Cellular Organelle Functions, cont…
C. Nucleolus
1. Location: inside the nucleus (p. 181)
2. Function: Stores RNA
Used to decode the information contained in DNA
3. RNA stands for Ribonucleic Acid
a) RNA makes, assembles, and produces ribosomes
b) RNA directs protein synthesis
Comparing DNA and RNA
DNA
RNA
Sugar is Deoxyribose
Sugar is ribose
Comparing DNA and RNA
DNA
RNA
Sugar is Deoxyribose
Sugar is ribose
Double Stranded
Single Stranded
Comparing DNA and RNA
DNA
RNA
Sugar is Deoxyribose
Sugar is ribose
Double Stranded
Single Stranded
THYMINE, Adenine,
Cytosine, Guanine
URACIL, Adenine
Cytosine, Guanine
Cellular Organelle Functions, cont…
D. Ribosome
1. Tiny particles made of protein + DNA
2. Function: protein synthesis
 Site where proteins are assembled (with directions from
DNA)
3. Amino acids are the building blocks of protein
4. Found Attached to Endoplasmic Reticulum ( know
then as the Rough E.R.)
5. Also Found free floating throughout the cytoplasm
of the cell. Known as Free Ribosomes
Cellular Organelle Functions, cont…
E.
Endoplasmic Reticulum
a. an internal membrane system
b. A system of membranes inside the cell that:
1. Modify proteins made in the Rough E.R.
2. Manufacture Lipid components of the cell membrane
c. There are 2 forms of ER:
a.
Smooth
b.
Rough (with ribosomes)
Cellular Organelle Functions, cont…
F. Golgi Apparatus (body, complex)
1. These 2 organelles modify + add components to
proteins and then ship them to their final destination
2. A membranous, stacked plate-like structure which
functions in:
a. Packaging protein
b. Storing protein
c. Exporting protein
d. Making lysosomes
Cellular Organelle Functions, cont…
G. Lysosomes
1. Sac-like membranes filled with enzymes
and peroxide that digest things in the cell
*Responsible for eating away tissue to
sculpt ears, fingers, toes
2. Sometimes referred to as ‘suicide sacs’
because they digest the cell itself
Cellular Organelle Functions, cont…
H. Mitchondria
1. Often referred to as the Powerhouse of the cell
because they supply energy
2. Site of Cellular Respiration
a. O2 + C6H12O6  CO2 + H2O + energy
b. Oxygen + Glucose yields Carbon dioxide + water and energy
c. Energy is in the form of ATP (adenosine tri phosphate)
d. Each glucose molecule form 36 ATP molecules
e. Fatty acids and lipid produce much more
E. ATP is broken to release energy and reformed to store energy over and
over again resulting in daily expenditure ranging the trillions of ATP
molecules
Cellular Organelle Functions, cont…
I. Microtubules (cytoskeleton) & Microfilaments
 Structure + Support
 Make up cilia + flagella
J. Cell Wall (not found in animal cells)
 Made of cellulose (indigestible for us)
 Function: protection, support
Cellular Organelle Functions, cont…
I.
Vacuoles
 A sac-like structure which functions in storage
 2 types:
1. Food Vacuole ; stores food
2. Contractive Vacuole: pumps out excess H2O
Like a sump pump
Helps with homeostasis
Cellular Organelle Functions, cont…
L.
Plastids – pigment holders (only found in plant and some protists)
1.
Chloroplast = green pigment (most important for photosynthesis
Accessory pigments are needed to capture light energy throughout the entire
visible spectrum
Photosynthesis: H2O + CO2 => C6H12O6 + O2
 Water + Carbon dioxide yields glucose + oxygen
 Plants have mitochondria also used to convert glucose into
ATP
1.
Leucoplasts = starch grains (glucose is converted and stored as
starch)
Where did the Cell Come From?
A. Oparin: Russian scientist who
proposed the idea that cells arose from
a chemical mixture known as
“primordial soup”