Cellular Structure
Biology
Mr. Foster
Write what is
underlined
Components of Cells
1. Nucleus-
2. Outer Boundary-
3. Cytoplasm / Organelles- cellular contents and
specialized structures that carry out functions
of the cell
Nucleus
• Prokaryote- cell w/o
nucleus
– (DNA in neucleoid)
• Eukaryote- cell with
nucleus
• Functions
– Contains genetic inform.
– Control Center- directs all
cellular activity
Nucleus (cont.)
• Structure / Components– Nuclear envelope- regulate
what enters and leaves nucleus
(Nuclear pores)
– Nucleolus- makes ribosomes
– Genetic Material- DNA
• Chromatin – DNA uncoiled,
threadlike, Not Divisional
• Chromosomes –DNA is
condensed, Divisional
Clicker ?’s 1-4
Outer Boundary
• Cell membrane- selective boundary
• All cells have a cell membrane
• Cell wall –
– give plant and bacteria cells
structure
Cell Membrane (cont.)
•
Structure- Fluid Mosaic Model
1. Phospholipids
Phosphate- likes H2O
(hydrophilic)
Lipid- does not like
H2O (hydrophobic)
•
Phospholipid bilayer
forms membrane
Clicker ?’s 5 & 6
Cell Membrane (cont.)
• Structure provided to membrane by…
4. Cytoskeleton – supports the membrane
a. microfilaments - strength, anchor cells
b. microtubules – movement
Cytoskeleton
Clicker ?’s 7-9
Cytoplasm
• Cytoplasm – space between nucleus and cell
membrane
– Cytosol – semitransparent; jellylike substance that
surrounds organelles
Organelles- “little organ”
• Endoplasmic Reticulum– Transports materials through inside
of cell
– Modifies proteins and quality control
center
• Types of ER
– Rough ER
• Has ribosome attached
• Proteins to be sent outside cell
– Smooth ER
• No ribosomes
• Make lipids, detox cell
Smooth or
Rough?
Organelles (cont.)
• Ribosome– Synthesize proteins
– Free vs. attached
Organelles (cont.)
• Mitochondria
– Provides energy for the cell ATP
• Cellular respiration
– Own DNA
– Endosymbiont Theory
• Free living organism that
entered a relationship w/
Nucleated cells
– Inherited from mother only
– Folds increase surface
area
Organelles (cont.)
• Lysosomes
– Membrane bounded sacs that contain enzymes
– Clean up cell
– Lysosomal Storage disease
(Tay Sachs)- missing the
enzyme that breaks down the
lipid that surrounds the nerve
cell
Buries the nervous system
Organelles (cont.)
• Centrioles
– Function in cell division
• Organize spindle fibers
Clicker ?
10-16
Organelles (cont.)
• Golgi Apparatus (Golgi bodies) modifies,
sorts, and ships proteins
in packages called
vesicles.
What is this?
Plant Cells Contain Some Structures That
Animal Cells Lack
• Plant cells have three
additional structures
that are not found in
animal cells.
– A cell wall
– Several chloroplasts
– Central vacuole
• These three structures
are shown in the plant
cell to the right.
Cell Transport
• Passive – energy not required to move
material across membrane
– Diffusion – molecules move from high to low
concentration to reach equilibrium
Cell Transport
• Passive Transport (cont)• Osmosis – type of diffusion involving H2O molecules
only
Cell Transport (cont.)
• Active – Energy required to move materials
across membrane
Low to High concentration
– Ion pumps/Channels- Cl-, Na+, K+, Ca+
– Endocytosis / Exocytosis – membrane forms
pockets to move material
Clicker ?’s 17-20
Endocytosis / Exocytosis