BIOL 111 EXAM 2 STUDY NOTES
Chapter 5: Membrane Structure
● A membrane is a collage of different proteins embedded in the fluid matrix of the lipid
bilayer
○
● Cells: The Basis Units of Life
○
○
○
, ■ Humans are composed entirely of cells, or basic units of self-contained
biological function
■ Different kinds of cells work together to produce tissues, which in turn
combine forces to create organs, and these taken together comprise a
plant, animal, or fungus. Cells are incredibly small
○ Robert Hooke (1635-1703)
■ Published the first account of the microscopic world, in a book called
Micrographia in 1664
■ Coined the term “cells” because they looked like little rooms that monks
worked in (cellula)
○ Cell Theory
■ Over the next several hundred years, data from micrographic studies
poured in elucidating the functions of tissues within organisms, and the
role of pathogens in disease.
■ The result of this is what has been called “cell theory” which includes four
premises:
● All living organisms are made of one or more cells
● Chemical reactions are necessary for life to take place within cells
● All cells arise only from pre-existing cells
● Cells contain hereditary information in the form of DNA
○
● Differences Btwn Pro/Eu Karyotes:
○
■ Prokaryotic Cells
, ● Single-celled
● DNA concentrated in nucleoid
● Cellular function takes place in the cytoplasm (ribosomes also
found there)
● Plasma membrane and cell wall
● Capsule - jellylike outer coating for protection, adhere
● Pili - bridge like structure used to transfer info
● Flagella - tail-like appendage used for locomotion
○
■ Specific types of prokaryotes
● Cyanobacteria (blue-green bacteria)
○ Photosynthetic
○ Huge environmental role
■ O2 production
■ Progenitor of plant chloroplasts
○ Some live in the fur of sloths, providing a form of
camouflage
● Bacteria
○ 3 basic morphotypes: Coccus (circle), Bacillus (rod), and
spirillum (spiral)
○ Many are important in our everyday lives
■ 10x more bacterial cells
■ 500-1000 species
, ○ Relatively few bacteria are pathogenic… BUT
○
■ Specific types of Eukaryotes
● Protists
● Plants
● Fungi
● Animals
○ True nucleus and organelles
○ Can be unicellular
○ Sexual reproduction, BUT some are asexual
○ Linear chromosomes
○ Evolved from prokaryotic ancestor via endosymbiosis
■ Endosymbiotic origins of eukaryotes (endo:within, sym:same, bio:life,
osis:form)
● Very ancient bacteria are unable to live in environments with large
quantities of free oxygen, which is fine because free oxygen was
absent from the early atmosphere.
● However, some prokaryotes evolved photosynthesis which
absorbs carbon dioxide and releases free oxygen
● In response, some other prokaryotes evolved an efficient means
of dealing with the free oxygen by means of a process called
respiration
● Lynn Margulis hypothesis was that an early prokaryote that could
not deal the the free oxygen ingested one that could, and rather
than digesting it, it used it as a partner in feeling with increasing
levels of atmospheric oxygen.
● In return, the oxygen absorbing partner obtained a safe place from
other hungry prokaryotes, and eventuall became what we call the
mitochondria.
● In a second event at the base of the plant lineage, a second
endosymbiotic event occurred in which a prokaryote that could
perform photosynthesis was absorbed → this allowed the
three-prokaryote complex to live in diverse environments and
produce its own food… good for everyone involved.
Chapter 5: Membrane Structure
● A membrane is a collage of different proteins embedded in the fluid matrix of the lipid
bilayer
○
● Cells: The Basis Units of Life
○
○
○
, ■ Humans are composed entirely of cells, or basic units of self-contained
biological function
■ Different kinds of cells work together to produce tissues, which in turn
combine forces to create organs, and these taken together comprise a
plant, animal, or fungus. Cells are incredibly small
○ Robert Hooke (1635-1703)
■ Published the first account of the microscopic world, in a book called
Micrographia in 1664
■ Coined the term “cells” because they looked like little rooms that monks
worked in (cellula)
○ Cell Theory
■ Over the next several hundred years, data from micrographic studies
poured in elucidating the functions of tissues within organisms, and the
role of pathogens in disease.
■ The result of this is what has been called “cell theory” which includes four
premises:
● All living organisms are made of one or more cells
● Chemical reactions are necessary for life to take place within cells
● All cells arise only from pre-existing cells
● Cells contain hereditary information in the form of DNA
○
● Differences Btwn Pro/Eu Karyotes:
○
■ Prokaryotic Cells
, ● Single-celled
● DNA concentrated in nucleoid
● Cellular function takes place in the cytoplasm (ribosomes also
found there)
● Plasma membrane and cell wall
● Capsule - jellylike outer coating for protection, adhere
● Pili - bridge like structure used to transfer info
● Flagella - tail-like appendage used for locomotion
○
■ Specific types of prokaryotes
● Cyanobacteria (blue-green bacteria)
○ Photosynthetic
○ Huge environmental role
■ O2 production
■ Progenitor of plant chloroplasts
○ Some live in the fur of sloths, providing a form of
camouflage
● Bacteria
○ 3 basic morphotypes: Coccus (circle), Bacillus (rod), and
spirillum (spiral)
○ Many are important in our everyday lives
■ 10x more bacterial cells
■ 500-1000 species
, ○ Relatively few bacteria are pathogenic… BUT
○
■ Specific types of Eukaryotes
● Protists
● Plants
● Fungi
● Animals
○ True nucleus and organelles
○ Can be unicellular
○ Sexual reproduction, BUT some are asexual
○ Linear chromosomes
○ Evolved from prokaryotic ancestor via endosymbiosis
■ Endosymbiotic origins of eukaryotes (endo:within, sym:same, bio:life,
osis:form)
● Very ancient bacteria are unable to live in environments with large
quantities of free oxygen, which is fine because free oxygen was
absent from the early atmosphere.
● However, some prokaryotes evolved photosynthesis which
absorbs carbon dioxide and releases free oxygen
● In response, some other prokaryotes evolved an efficient means
of dealing with the free oxygen by means of a process called
respiration
● Lynn Margulis hypothesis was that an early prokaryote that could
not deal the the free oxygen ingested one that could, and rather
than digesting it, it used it as a partner in feeling with increasing
levels of atmospheric oxygen.
● In return, the oxygen absorbing partner obtained a safe place from
other hungry prokaryotes, and eventuall became what we call the
mitochondria.
● In a second event at the base of the plant lineage, a second
endosymbiotic event occurred in which a prokaryote that could
perform photosynthesis was absorbed → this allowed the
three-prokaryote complex to live in diverse environments and
produce its own food… good for everyone involved.
