Cell Structure and Function Chapter 4 Outline Cell Theory Cell Size

Outline
Cell Structure and Function
•
Chapter 4
•
•
•
Mader: Biology 8th Ed.
Cell Theory
Cell Size
Prokaryotic Cells
Eukaryotic Cells
– Organelles
! Nucleus
! Endomembrane System
! Cytoskeleton
! Centrioles, Cilia, and Flagella
Mader: Biology 8th Ed.
1
2
Cell Theory
•
Cell Size
Cell theory states all organisms are
composed of cells and that cells come only
from preexisting cells.
– One of unifying concepts of biology.
•
•
Mader: Biology 8th Ed.
Most cells are much smaller than one
millimeter.
– Some as small as one micrometer.
Small cells are likely to have an adequate
surface area for exchanging wastes for
nutrients.
– Cells that specialize in absorption have
modifications that greatly increase the
surface area per volume of the cell.
Mader: Biology 8th Ed.
3
4
Organism Sizes
Prokaryotic Cells
•
•
•
Mader: Biology 8th Ed.
Lack a membrane-bounded nucleus.
Structurally simple.
Can be divided into two domains:
– Bacteria
! Three Shapes
" Bacillus (rod)
" Coccus (spherical)
" Spirilla (spiral)
– Archaea
! Live in extreme habitats.
Mader: Biology 8th Ed.
5
6
Prokaryotic Cells
•
Prokaryotic Cells
Cell Envelopes
– Includes plasma membrane, cell wall, and
glycocalyx (layer of polysaccharides
outside cell wall).
! Capsule – Well-organized layer.
– Form internal pouches (mesosomes).
•
•
Mader: Biology 8th Ed.
Cytoplasm
– Cytoplasm is a semifluid solution
encapsulated by plasma membrane.
! Inclusion Bodies - Stored granules of
various substances.
Appendages
– Flagella
– Fimbriae
– Sex Pili
Mader: Biology 8th Ed.
7
8
Prokaryotic Cells
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
9
10
Eukaryotic Cells
•
•
•
•
Organelles
Members of domain Eukarya.
Contain membrane-bounded nucleus.
Contain specialized organelles.
Contain plasma membrane.
•
•
Mader: Biology 8th Ed.
Organelles of endomembrane system
communicate with one another.
– Basically self-sufficient
Compartmentalization allows eukaryotic
cells to be larger than prokaryotic cells.
Mader: Biology 8th Ed.
11
12
Animal Cell Anatomy
Plant Cell Anatomy
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
13
Nucleus
•
•
14
Anatomy of Nucleus
Contains chromatin in semifluid
nucleoplasm.
– Condense to form chromosomes.
Separated from cytoplasm by doublemembrane nuclear envelope.
– Nuclear pores permit passage in and out
of the nucleus.
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
15
16
Ribosomes
•
•
Composed of large and small subunits that
serve in protein synthesis.
– Subunits made in nucleolus.
Occur singly and in groups, and may
become attached to endoplasmic reticulum.
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
17
Endomembrane System
•
•
18
Endoplasmic Reticulum
Consists of nuclear envelope, membranes
of endoplasmic reticulum, Golgi apparatus,
and several types of vesicles.
– Restrict enzymatic reactions to specific
compartments within cell.
Endoplasmic Reticulum
– Rough - Studded with ribosomes.
– Smooth - No ribosomes.
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
19
20
Endomembrane System
•
Endomembrane System
Golgi Apparatus
– Consists of flattened, curved saccules.
– Modifies proteins and lipids and packages
them in vesicles.
•
Mader: Biology 8th Ed.
Lysosomes
– Membrane-bounded vesicles produced by
the Golgi apparatus.
! Engage in digestion of molecules and
apoptosis (programmed cell death).
Mader: Biology 8th Ed.
21
22
24
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
23
24
Peroxisomes and Vacuoles
•
•
Peroxisomes are membrane-bounded
vesicles that enclose enzymes.
– Enzymes are cell-specific
Vacuoles are membranous sacs that are
larger than vesicles.
– Store substances
– Plants cells typically have a central
vacuole that functions in storage of
nutrients and waste products.
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
25
26
Energy-Related Organelles
•
•
Mader: Biology 8th Ed.
Chloroplasts use solar energy to synthesize
carbohydrates.
– Photosynthesis
! Cellular Respiration
– Adenosine triphosphate (ATP) is used for
all energy-requiring processes in cells.
Chloroplasts are green due to the green
pigment chlorophyll.
– Stroma
– Granum
Mader: Biology 8th Ed.
27
28
Chloroplast Structure
Energy-Related Organelles
•
•
Mader: Biology 8th Ed.
Mitochondria are involved in cellular
respiration.
Produce most of ATP utilized by the cell.
– Cristae - Inner membrane that encloses
matrix.
– Matrix - Enzymes that break down
nutrient molecules.
Mader: Biology 8th Ed.
29
30
Mitochondrion Structure
Cytoskeleton
•
Mader: Biology 8th Ed.
Cytoskeleton serves as internal skeleton
that maintains cell shape and assists in
movement of its parts.
– Actin Filaments
! Pseudopods
– Intermediate Filaments
– Microtubules
Mader: Biology 8th Ed.
31
32
Fig. 4.18
Centrioles, Cilia, and Flagella
•
•
Mader: Biology 8th Ed.
Centrioles are short cylinders with a 9 + 0
pattern of microtubule triplets that may give
rise to basal bodies of cilia and flagella.
Cilia and flagella are hairlike projections with
a 9 + 2 pattern of microtubules that aid in
cell movement.
– In eukaryotes, cilia are much shorter than
flagella.
Mader: Biology 8th Ed.
33
34
Review
•
•
•
•
Mader: Biology 8th Ed.
Cell Theory
Cell Size
Prokaryotic Cells
Eukaryotic Cells
– Organelles
! Nucleus
! Endomembrane System
! Cytoskeleton
! Centrioles, Cilia, and Flagella
Mader: Biology 8th Ed.
35
36
Mader: Biology 8th Ed.
37