cell structure and growth

class one

microbial physiology

structure-function relationships in microorganisms, especially how microbes respond to their environment

cytoplasmasm

gel-like network; crowded with proteins and other molecules

plasma membrane

encloses the cytoplasm; composed of phospholipids, membrane proteins, and other molecules

cell wall

covers the cell membrane; composed of peptidoglycan

outer membrane

gram negative: LPS, phospholipid, proteins

ribosomes

responsible for protein synthesis. rRNA + riboproteins

nucleoid

chromosomal DNA + DNA associated proteins

flagllum

external helical filament whos rotary motor propels the cell

all life on earth is based on

carbon

autotrophs

fix CO2 and assemble into organic molecules. make their own food from inorganic substances

heterotrophs

assimilate organic compounds as carbon sources. cannot make their own food, obtain energy by consuming other organisms

phototrophs

obtain energy from chemical reactions triggered by light (photosynthesis)

chemotrophs

obtain energy from oxidation-reduction reactions

lithotrophs

use inorganic molecules as electron sources

organotrophs

use organic molecules as electron sources

most organisms are

chemoorganoheterotrophs

chemoorganoheterotrophs

organisms that get energy from chemical reactions, use organic compunds as its electron source, get carbon from organic compounds

aka- get energy, electrons, and carbon from all organic matter

humans, animals, fungi, many bacteria

types of culture media

complex media and defined (synthetic) media

complex media

nutrient rich but contain poorly defined ingredients (e.g. yeast extract or beef extract)

defined (synthetic) media

precisley defined; used to characterize the phenotype of a mutant

population growth

often studied in batch culture: liquid culture in a closed system with a single batch of medium

four phases- lag phase, exponential (log) phase, stationary phase, death phase

what happens during binary fission

population doubles every generation

binary fission exponential growth equation

Nt = N0 × 2^n

Nt= final number of cells

N0= initial number of cells

n= number of generations

what is generation time and how is number of generations calculated

amount of time it takes a population to double in size

equation: n = log2(Nt/N0)

origin of life on earth order

1. bacteria

2. archaea

3. eukaryotes

4. plants

5. fungi

6. protosomes

7. echinoderms

8. fish

9. amphibians

10. reptiles

11. birds

12. mammals