Class Notes (837,698)
Canada (510,399)
BISC 110 (14)
Lecture 4

Lecture 4 notes.doc

4 Pages
Unlock Document

Biological Sciences
BISC 110
Robin Barrow

Lecture 4- Prokaryotes and the evolution of metabolism Chapter 25, pp. 514-516 Chapter 27, pp. 566-567, p. 570 (sections on Archaea and Bacteria only) Chapter 27, Concept 27.3: pp. 564-565 Geological Record •divided into 3 eons •Archaean •Proterozoic •Phanerozoic •Paleozoic •Mesozoic (age of reptiles) •Cenozoic •each boundary between eras represent extinctions and formations Prokaryotes (pro: before, karyos: nucleus) •most ancient unicellular organisms (earth's sole inhabitants) •lived alone on Earth for nearly 2 bya; they created the life on Earth •greatest diversity of lifestyles and habitats •have a high range of metabolic adaptions, more than eukaryotes •their domain: •Bacteria •includes most known prokaryotes •huge diverse metabolism & structure •includes: •photosynthetic cyanobacteria •organisms important in decomposition and nutrient cycles •some disease organisms •peptidoglycan in cell wall •famous bacteria: •borrelia: lyme disease caused by spiral shaped bacteria (ticks) •salmonella: in your food (contamination of raw meats) •Archaea •how they're different from bacteria: •cell wall composition •details of protein synthesis •live in harsh environments; prokaryotes (Extremophiles: 'extreme-lovers') •famous archaea: •methanogens: methane-makers, in guts of animals (use CO2 to oxidize H2, producing energy and methane waste; methanogens are poisoned by O2) •halophiles: salt-lovers •thermophiles: heat-lovers, in smoking vents living 121° (Eukarya: NOT prokaryotes...protists, fungi, plants, animals) Prokaryotes VS Eukaryotes •Prokaryotic cells •smaller with single membrane •nucleoid with no membrane •no nucleus •no walled organelles •no cytoskeleton Modern prokaryotes as clues to evolution of metabolism •some prokaryotes today lived in environments similar to those in early earth •metabolism of modern prokaryotes similar to metabolism of ancient prokaryotes •phototrophs: obtain energy from light •chemotrophs: obtain energy from chemicals •autotrophs: obtain energy from carbon source •heterotrophs: obtains energy from organic nutrient to make other organic compounds •Nutritional mode; NRG + carbon sources used as energy •Photo-autotroph; Light + CO2 •Chemo-autotroph; Inorganic chemicals + CO2 •Photo-heterotroph; Light + Organic compounds •Chemo-heterotroph; Organic compounds •Respiratory mode: •Obligate anaeroby: Fermentation/anaerobic respiration; never uses O2 •Facultative anaeroby: O2 if pres
More Less

Related notes for BISC 110

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.