Cellular Architecture
Or the typical/nontypical cell
Figur
I.
Limits to cell size
A. Surface to volume ratio
1. function of membrane
2. relationship of surface area to volume
3. consequences of growing too large
1 mm
2 mm
2 mm
1 mm
Figur
I.
Limits to cell size
B. Control issues
1.
2.
3.
4.
5.
Informational flow
Transcription
Diffusion
Translation
Cell gets too large, lag time
in the control of activities
6. Analogy
II. Few Generalizations
• A. Procaryotic vs.
eukaryotic
• B. Typical cell
– 1. animal
– 2. plant
– 3. discuss the
similarities first
III. Organelles of synthesis
• A. Introduction
– 1.
– 2.
– 3.
– 4.
– 5.
Going to act as an assembly line
Nucleus
Endoplasmic reticulm
ribosome
Golgi apparatus
III. Organelles of synthesis
B.
Nucleus-headquarters
1. chromatin
2. chromosomes
3. nucleolus
4. double membrane
with pores
Nuclear Pores From Surface of Nuclear Membrane
Artist conception of nuclear pores
III. Organelles of synthesis
•
•
•
•
C.
1.
2.
3.
Endoplasmic Reticulum
definition
nickname
types of
– Rough
– Smooth
Rough and smooth endoplasmic reticulum
Endoplasmic reticulum continuous with pores
III. Organelles of synthesis
•
•
•
•
D.
1.
2.
3.
Ribosomes-protein synthesis
found free in cytoplasm-endogenous use
attached to E.R.-proteins for export
responsible for translation of mRNA into protein
Ribosomes translate mRNA
III.
Organelles of synthesis
• D. Golgi Body or Golgi
Apparatus
• 1. nick name of bottling center
• 2. modifies product
• 3. concentrates product
• 4. packages product into
vesicles
• 5. exports via exocytosis
III. Organelles of synthesis
• E. Cell membrane with
exocytosis
IV. Organelles of homeostasis
•
•
•
•
•
•
A. Mitochondria
Nickname
Structure
Endosymbiosis
More active tissue
Both animal and plant
B. Chloroplasts
• Nickname
• Structure
• Endosymbiosis
Mitochondria and chloroplasts are tied tightly
together
Cell wall
Vacuole
Granum
Plasma membrane
Stroma
Nuclear
envelope
Nucleolus
Smooth ER
Rough ER
Nuclear
pores
Chromatin
Nucleus
Ribosomes
Chloroplast
Rough and smooth endoplasmic reticulum (ER)
Figur
C. Lysosome
• Nickname
• Structure
• Functions
D. Peroxisomes
•
•
•
•
Similar in appearance to lysosomes
Contain enzymes important in lipid breakdown
Detoxification centers
Possess enzyme catalase important in the
breakdown of hydrogen peroxide
E. Cytoskeleton
Composed of microtubules and microfilaments
1. Microtubules
• “Skeleton” of the cell
• Produce the structural
framework for cilia and
flagella
2. microtubules
• Act as a railway along
which organelles travel
• Microtubules may walk
past one another
• Motor molecules may
transport organelles from
one area of the cytoplasm
to another
3. microfilaments
a.
b.
“muscles” of the cell
Same proteins that are found in our muscles
c.
d.
Cytokinesis
pseudopods
Microfilaments (cont)
e.
produce swaying of
microvilli
f.
Movements of
cytoplasmic streaming
Relationship of the cytoskeleton to the cell
membrane and extracellular fibers
F. Cell wall of plant cells
•
•
•
•
Primary cell wall
Secondary cell wall
Middle lamellae pectin
Importance of plasmodesmata
Plant
cell walls
Plasmodesmata
Plasmodesmata
G. Centrioles
H. Central vacuole
I. Cilia and flagella
• Microtubules
• 9 +2
• Triplets in basal
body
• Form from
centrioles?