Cells!!
Yay! We’re so excited!! I always wanted to learn about cells and
stuff…really Mr. Mason…I’m not bored….this is awesome…just like
cheese, which is also awesome…but not quite as awesome as cells.
Well, except for melted cheese…and that fancy cheese at
Costco…that stuff is pretty awesome. Wait…what was I saying???
Oh yeah…cells! Woohoo! 
Cell Theory
• Life consists of cells
• All cells are derived from pre-existing cells
Cell Theory
• Life consists of cells
• All cells are derived from pre-existing cells
– Cells are the smallest units of matter that exhibit
all five characteristics of life
Sizes of Cells
• Most bacteria:
1-10 μm
• Plant/animal cells: 10-100 μm
• Can see with unaided eye down to 0.2mm
(200 μm)
• Largest cell?
• Smallest cell?
Sizes of Cells
• Most bacteria:
1-10 μm
• Plant/animal cells: 10-100 μm
• Can see with unaided eye down to 0.2mm (200
μm)
• Largest cell?
• Smallest cell?
egg
Sperm
• http://learn.genetics.utah.edu/content/begin/cell
s/scale/
Eukaryotic Cells
• Defined by the
presence of membranebound organelles (little
organs).
• Prokaryotes (bacteria)
have an organelle
(ribosome), but they are
not membrane-bound
Cell Membrane = phospholipid bilayer
Functions of phospholipid bilayer
• Protection
• Transportation
• Chem. reactions
• Identification/commu
nication
Organelles that process info:
• Nucleus
and
Ribosomes
Nucleus
• Storehouse for genetic code (DNA)
• Synthesizes RNA and ribosomes
Ribosomes
• The site of protein synthesis
• Composed of proteins and rRNA (3 types of RNA in
cells – mRNA, tRNA, and rRNA…but we’ll get to that during 2nd
semester)
• Either free (proteins used in cytoplasm) or
attached to E.R. (proteins inserted into
membrane or used for export)
Organelles that process energy
• Mitochondria
and
plastids
Mitochondria
• Converts energy from
organic compounds
(such as glucose) into
ATP
• Have their own DNA
(only organelle that has
DNA other than the
nucleus)
Plastids
• Chloroplasts – convert
sunlight into glucose
• Chromoplasts – give fruits
and flowers their color
(why?)
• Leucoplasts – store starch
(energy source)
• Only found in plants
The endomembrane system
• Endoplasmic reticulum, golgi apparatus, and
lysosomes
Endoplasmic Reticulum
• Serves as an intracellular
highway
• Rough ER – covered in
ribosomes, produces
phospholipids and
proteins – especially for
export
• Smooth ER – produces
lipids (steroids, hormones,
etc.)
Golgi Apparatus
• Processing, packaging,
and secreting organelle
• Modifies proteins for
export
Lysosome
• The dumpster of the
cell
• Contains hydrolytic
enzymes that digest
organic molecules
Plant Cells – How are they unique?
• Plants have:
– Plastids
– Vacuoles: large storage organelle
– Cell wall covering phospholipid bilayer