Research!
• Look up each antibiotic from our lab and
describe what it does to bacteria.
• As a group, draw a picture that you
think best represents how each
antibiotic works.
Cells!
– The cell is the lowest level of structure that
can perform all activities required for life.
• Cell Theory:
– All living organisms are composed of cells.
– All cells come from other cells.
We can distinguish two major types of cells:
Prokaryotic
Eukaryotic
Photo source: Wikipedia
The
prokaryotic
cell is simple,
small, and
contains no
organelles.
The
eukaryotic
cell is larger
and more
complex
and
contains
organelles.
Prokaryotic and Eukaryotic Cells:
(DNA)
(DNA)
Cytosol
Cytosol
A prokaryotic cell
Two typical kinds
of eukaryotic cells:
- Animal cells
- Plant cells
Prokaryotic and Eukaryotic Cells:
What do all cells have in common?
(DNA)
(DNA)
Cytosol
Plasma membrane
Cytosol
Ribosomes
Chromosomes
made of DNA
Cytosol
A prokaryotic cell
Prokaryotic and Eukaryotic Cells:
What is their most significant difference?
Eukaryotic cells have
membrane-bound organelles
that perform
specialized functions
Prokaryotic cells
do not
Look more closely at
cellular structures and their functions
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
Plasma Membrane
– The plasma membrane separates the living
cell from its nonliving surroundings.
- Regulates traffic
into and out of
the cell
- Allows cell
to interact
with environment
Membrane Function
– A closer look at our membranes
Hydrophobic region
Hydrophilic
region
Cell Surfaces
– Most cells secrete materials for coats of one
kind or another that are external to (outside of)
the plasma membrane.
Cell Surfaces
– Animal cells have an extracellular matrix and cell
junctions,
• Which helps hold cells together in tissues and protects and
supports them (not shown).
Try giving your skin a good pull. If your skin is made out of cells,
how do they all stick together? Extracellular matrix and
junctions!
Cell Surfaces
– Plant cells and bacterial cells have cell walls,
• Which help protect the cells, maintain their shape, and keep
the cells from absorbing too much water.
Plant Cell Walls: Cellulose
Bacterial Cell Walls:
Peptidoglycan
Osmosis and the Cell Wall
Solute in = solute out
Water travels equally
Solute in > solute out
Water travels in
Solute in < solute out
Water travels out
Structure Meets Function
in a Cell
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
The Nucleus:
Genetic Control of the Cell
– The nucleus is the manager of the cell.
• Genes on the DNA in the nucleus store information
necessary to produce proteins.
Prokaryotes do not have nuclei.
Their genes (on DNA) are in the nucleoid region
Structure and Function of the Nucleus
– The nucleus is bordered by a double membrane
called the nuclear envelope.
• It contains chromatin and a nucleolus.
Chromatin:
long strands
of DNA and
associated
proteins.
The DNA
stores the
genetic
information
(genes).
Nucleolus:
assembles
ribosomes
Ribosomes: Protein Synthesis
– Ribosomes are responsible for protein synthesis.
How DNA Controls the Cell
– DNA controls the cell by transferring its coded
information into RNA.
• The information in the RNA is used to make proteins.
Eukaryotic cell
Prokaryotic cell
Structure Meets Function
in a Cell
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
The Endomembrane System: Manufacturing,
Distributing, and Storing Cellular Products
Not found in bacterial cells!
Structure Meets Function
in a Cell
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
Energy Conversion:
Chloroplasts & Mitochondria
– Cells require a constant energy supply to do all
the work of life.
Not found in bacterial cells!
Chloroplasts
– Chloroplasts are the sites of
photosynthesis, the conversion of light
energy to chemical energy.
All little green
circles are
chloroplasts
Cell walls
Mitochondria
– Mitochondria are the sites of cellular
respiration, which involves the production
of ATP from food molecules.
Structure Meets Function
in a Cell
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
The Cytoskeleton:
Cell Shape and Movement
– The cytoskeleton consists of a network of fibers.
Also, recently found in bacterial cells!
Cytoskeleton
– Mechanical support to
maintain cell shape
– Can change cell
shape to allow
movement
Structure Meets Function
in a Cell
• Plasma Membrane and Cell Surface
• Nucleus and Ribosomes
• Endomembrane System
–
–
–
–
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
• Energy Conversion: Chloroplasts and Mitochondria
• Cytoskeleton
• Cilia and Flagella
Cilia and Flagella
– Cilia and flagella are motile appendages.
Not found on most plant cells!
– Flagella propel the cell in a whiplike
motion.
– Cilia move in a coordinated back-and-forth
motion.