Lecture 1 - Introduction to Cell Biology

Cells

• fundamental unit of life

• many types

• variety of sizes, shapes, and functions

three characteristics that define a cell:

• replicatable genetic information (DNA)

• limiting membrand (plasma membrane)

• metabolic machinery (catabolism and anabolism)

Prokaryotes (bacteria & archaea)

• single compartment enclosed by plasma membrane

• contain essentially no organelles - naked DNA in the cytoplasm

• most live as single celled organisms, some form clusters

• live in a variety of environments

• aerobic and anaerobic

• food source: any organic material, some bacteria can live on inorganic substances

Eukaryotic Cell: Membrane-bound organelles

• plasma membrane - cytosolic compartment

• nuclear envelope - nucleus - information store

• endoplasmic reticulum - synthetic machinery (rough ER and smooth ER)

• golgi apparatus - protein modification, storage, shipment

• mitochondrion - energy generation

• chloroplast - capture energy from sunlight

• lysosome - digestion

• peroxisome - oxidation

Eukaryotic Cell: Non-Membranous organelles

• ribosomes - protein synthesis

• cytoskeleton - polarity and cell movement

  • composed of actin filaments, microtubules, and intermediate filaments