The study of cells
All living things are composed of cells
Cells are basic units of life
New cells come from pre-existing cells
BUT….
How did the very first cell get here????
Viruses lack typical cell structure, use host
cells to reproduce
Mitochondria and chloroplasts have their own
genetic material/can reproduce independent
of cell
Small
Simple
No Nucleus
No membrane bound organelles
Then what do they have?
Cell membrane
Cytoplasm
DNA: Circular, not in nucleus
Ribosomes
Bacteria
Prokaryotic Structure
cytoplasm
with ribosomes
DNA
cell
membrane
More complex
Larger
Plant cells
DNA in nucleus in long strands
Contain membrane bound organelles
Specialized compartment with a
specific function
Animal cells
Fungi (Yeast)
Oh where, oh where do we find cell organelles?
Cytoplasm (protoplasm):
The fluid inside a cell, but outside the nucleus
“Holds” organelles in place
Site of cellular chemical reactions
Cyclosis:
Streaming movement of cytoplasm
Cytoplasm
Cytoplasm
Nucleus:
Controls cell processes
Contains hereditary information (DNA)
Nucleolus: Ribosome formation
Nucleus
Nucleolus
Nucleolus
Nucleus
Mitochondria
Release energy from food to make useable energy (ATP)
Outer and inner membranes
Inner membrane folded
(Increased surface area)
Found in:
Animal cells
Plant cells
Contain their own DNA!
Mitochondria
Mitochondria
Chloroplasts
Site of photosynthesis
Convert light energy to chemical bond energy
Only in plant cells
Contain their own DNA!
Chloroplasts
Animal cells don’t
have
chloroplasts!!!
Ribosomes
Site of protein synthesis
Can be free in cytoplasm or attached to
endoplasmic reticulum
Ribosomes
Ribosomes
Endoplasmic reticulum
“ER”
A system of membranous sacs
Assembles components of cell membrane
Protein modification
Rough endoplasmic reticulum
Protein synthesis
Rough: Ribosomes
RER
Smooth endoplasmic reticulum
Contains enzymes needed for cell
Ex. enzymes for lipid synthesis
Smooth: No ribosomes
SER
Rough ER
Smooth ER
Smooth ER
Rough
ER
Golgi Who?
apparatus, complex, bodies
Marks proteins for use in cell or
export (adds address w/proteins)
Produces digestive enzymes
Golgi
body
Golgi body
assorted
vesicles
Golgi
body
smooth ER
rough ER
Chains are
assembled on
ribosomes in
cytoplasm.
DNA instructions for
building protein
chains leave the nucleus
and enter the cytoplasm.
Lysosome
Packaged by Golgi body
Membranous sac filled with digestive enzymes
“Suicide Sacs”
Lysosomes
Lysosome
Lysosome
Vacuole
Cell storage:
Water
Food
Wastes
Plants:
One large central vacuole
Animals: Few small vacuoles
Vacuoles are crucial in single-celled organisms to
maintain homeostasis
Vacuole
Cell Wall
Provides support
Provides shape
Made up mostly of cellulose
Animal cells don’t have!
Cell wall
Animal cells
don’t have
cell walls!!!
Centriole
Used in cell division
Animal cells only
Plant cells
don’t have
centrioles!!!
Centriole
Cilia: Locomotion
Moving substances across surface of cell
Flagella: Locomotion
Cilia
Plasma membrane/cell membrane
Plant AND animal cells
Controls what goes in and out of cell
Protection
Support
Cell
membrane
Cell
membrane
Lipid Bilayer
• Main component of
cell membranes
lipid
bilayer
fluid
fluid
Cell (Plasma) Membrane Structure
☼ 2 layers of phospholipids
(lipids with phosphate groups attached)
☼ Proteins - embedded in lipid layers- for
transport or receptors
☼ Carbohydrates - attached to surface proteins
or lipids – markers
☼ Lipids & Proteins can move along membrane
= “Fluid”
FLUID MOSAIC MODEL of Cell Membrane
Receptors recognize substances (hormones etc.)
and allow them to enter cell
Animal Cells Plant Cells
Cell Walls
NO
YES
Chloroplasts
NO
YES
Centrioles
YES
NO
1 or 2
100 +
Golgi Bodies
Vacuoles
Many Small
Few Large
Cell wall
Chloroplasts
Cell
membrane
Vacuole
Mitochondria
Ribosomes
Lysosome
Golgi
body
Nucleus
Nucleolus
Smooth
endoplasmic
reticulum
Rough endoplasmic
reticulum
Cytoplasm
Golgi body
Cilia
Cell membrane
Centrioles
Smooth endoplasmic
reticulum
Lysosomes
Free ribosomes
Mitochondria
Nucleolus
Rough endoplasmic
reticulum
Nucleus
Cytoplasm
Staining Techniques
Applying stain makes cell structures more visible
Can be useful in identifying organisms
Example:
Methylene blue
Organelle
Cell
Tissue
Organ
Organ System
Organism