Lecture 1 Intro to Cells & Nucleic Acids
Tree of Life – share similar things (DNA, RNA, proteins)
-Composed of 3 major kingdoms:
oBacteria (Eubacteria) – true/normal bacteria
oArchaea (archaebacteria) – characteristics of eubacteria &
eucaryotes, grow in diverse places (thermal places, sewage pits, salt
marshes, high acid, low places)
oEucaryotes – multicellular (vertebrates, invertebrates,
plants, humans) or single-celled (protists)
2 main types of cells:
1) Procaryotic cells
-Single-celled (mostly exist as independent individuals, known to form colonies/communities)
-Bacteria & archaea
2) Eucaryotic cells
-Nuclei (nucleic acids are separated by nuclear membrane)
-Multicellular (not always)
-Plants, fungi, animals, humans
-Very simple cell, not many specialized compartments
-Plasma membrane – serves as filter to separate inside from
outside & mediate what diffuses in/out
-Nucleiod – nucleic acids that are not enclosed by any sort of
-Cell wall – protects bacteria from outside
-Ribosomes – sites of protein synthesis & free-floating in cytosol.
-Much more complex & divided into many different types
of specialized compartments.
-Larger (though not always)
-Much greater degree of complexity requires structural
elements called cytoskeleton which mediate division of cell
into specialized compartments, mediate shape cell can
have, movements of cell towards things.
-Microtubule – help move different organs & proteins
up/down these structures.
-DNA – contained w/in nuclear envelope.
-Ribosomes – tend to be organized into structure called
endoplasmic reticulum although some occur in cytosol.
-Energy-producing units are contained in mitochondria