CHAPTER 6.1 Flashcards
essential nutrient
any substance that must be provided to an organism
macronutrient
required in relatively large quantities and plays a principle role in cell structure and metabolism
EX: C, H, O
micronutrient
otherwise known as trace elements, are present in smaller amounts and are involved in enzyme function and maintenance of protein structure.
EX: Mn, Zn, Ni
heterotroph
organism that obtains carbon in organic form by consuming organic compounds
autotroph
organism that uses inorganic CO2 as its carbon source and is not dependent on other living things
phototroph
photosynthetic, where they capture light energy and transform it into chemical energy to produce organic molecules
chemoautotrophs
Two types
1. lithoautotroph- require neither sunlight or organic nutrients. only relies on inorganic minerals
2. chemoheterotroph- processes organic molecules for energy and inorganic compounds as a carbon source
phototroph and chemotrophs get their energy how
- phototroph- from light
- chemotroph- processes organic molecules by cellular respiration/fermentation
Saprobes/parasites
saprobes- free living mo that feed on organic detritus from dead organisms
parasites- ordinarily derive nutrients from cells or tissues of living host
essential nutrients
CHONPS
diffusion and the three types
movement from high to low conc.
1.simple- substances move on a gradient high to low
2. facilitated- molecules bind to a specific receptor and its carried out to the other side. can go in either direction
3. active- carrier mediated active transport; atoms or molecules are pumped into or out of the cell by specialized receptors
endocytosis
substances transported do not physically pass through but are carried into the cell by being enclosed/engulfed by the membrane.
phagocytosis
amoeba and certain white blood cells ingest cells or large solid matter by this process
pinocytosis
liquids, such as oils or molecules in solution enter the cell through this process
binary fission
when bacteria cell becomes into two. the parent cell enlarges, duplicates its chromosome and starts to pull the cell envelope together in the center using a band of proteins called microtubules (actin+tubulin)
septum formation
during binary fission, the creation of the dividing wall between the two cells
After binary fission, both daughter cells are_______
identical
lag phase in bacterial growth
relatively flat period on the graph when the population appears not to be growing or is growing at less than the exponential rate.
cause of lag phase in bacterial growth
the newly inoculated cells required a period of adjustment, enlargement and synthesis. the cells are not yet multiplying at their max rate. population of cells is so diluted that the sampling missed them
exponential, or log, phase in bacterial growth
the cells reach a max rate during cell division during this period where it increases geometrically
stationary phase in bacterial growth
when the population enters a period where cell birth/death rate are more or less equal
cause of stationary phase in bacterial growth
cause dby the depletion of nutrients and o2 plus excretion of organic acids and other biochemical pollutants
death phase in bacterial growth
self explanatory via name; as the limiting factors intensify, cells die at an exponential rate and unable to multiply. Speed depends on their resistance.
turbidity
indicator of cell growth in solution, identifiable as a cloudy appearance.
