Cell Biology

Robert Hooke, and his drawing of cells

Van Leeuwenhoek and his microscope

Schleiden and Schwann

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells(eubacteria and archaea)

- no nucleus - no organelles

- binary fission- small (0.2 – 2.0 um)

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells

- biofilms

Staphyloccocus aureus biofilm

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells2. Eukaryotic Cells(protists, plants, fungi, animals)

- nucleus - organelles - mitosis - larger (10-100 um)

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells2. Eukaryotic Cells

B. How Cells Live - take stuff in

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells2. Eukaryotic Cells

B. How Cells Live - take stuff in - break it down and harvest energy (enzymes needed)

ADP +P ATP

mitochondria

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells2. Eukaryotic Cells

B. How Cells Live - take stuff in - break it down and harvest energy (enzymes needed)

and - transform radiant energy to chemical energy

ADP +P ATP

mitochondria

ADP +P ATP

chloroplast

Cell BiologyI.Overview A. Types of Cells

1. Prokaryotic Cells2. Eukaryotic Cells

B. How Cells Live - take stuff in - break it down and harvest energy (enzymes needed) - use energy to make stuff (like enzymes and other

proteins,and lipids,

polysaccharides, and nucleic acids)

- DNA determines sequence of amino acids in enzymes and other proteins

ADP +P ATPribosome

ADP +P ATPribosome

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure

1. phospholipids

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure

2. proteins and carbohydrates

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier

Aqueous Solution (inside cell)

dissolved ions

dissolved polar molecules

suspended non-polar(lipid soluble)

Aqueous Solution (outside cell)

dissolved ions

dissolved polar molecules

suspended non-polar(lipid soluble)

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport

Net diffusion Net diffusion equilibrium

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport - diffusion

Net diffusion Net diffusion equilibriumNet diffusion Net diffusion Equilibrium

Net diffusion Net diffusion Equilibrium

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport - osmosis

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport – facilitated diffusion

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport – active transport

Cytoplasmic Na+ bonds tothe sodium-potassium pump

Na+ binding stimulatesphosphorylation by ATP.

Phosphorylation causesthe protein to change itsconformation, expelling Na+

to the outside.

Extracellular K+ bindsto the protein, triggeringrelease of the phosphategroup.

Loss of the phosphaterestores the protein’soriginal conformation.

K+ is released and Na+

sites are receptive again;the cycle repeats.

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport3. metabolism (enzymes nested in membrane)4. signal transduction

Cell BiologyI.OverviewII. Membranes – How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function

1. semi-permeable barrier2. transport3. metabolism (enzymes nested in membrane)4. signal transduction5. cell-cell binding6. cell recognition7. cytoskeleton attachment

Study Questions: 1. List three differences between prokaryotic and eukaryotic cells. 2. What is a biofilm? 3. Describe the function of mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, and liposomes. 4. Why is the lipid bilayer a barrier to water soluble molecules? 5. Describe diffusion, facilitated diffusion, and active transport. 6. How does solute concentration and pressure affect water potential and osmosis.