CHAPTER 6.1

Question 1

essential nutrient

Answer 1

any substance that must be provided to an organism

Question 2

macronutrient

Answer 2

required in relatively large quantities and plays a principle role in cell structure and metabolism
EX: C, H, O

Question 3

micronutrient

Answer 3

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

Question 4

heterotroph

Answer 4

organism that obtains carbon in organic form by consuming organic compounds

Question 5

autotroph

Answer 5

organism that uses inorganic CO2 as its carbon source and is not dependent on other living things

Question 6

phototroph

Answer 6

photosynthetic, where they capture light energy and transform it into chemical energy to produce organic molecules

Question 7

chemoautotrophs

Answer 7

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

Question 8

phototroph and chemotrophs get their energy how

Answer 8

1. phototroph- from light
2. chemotroph- processes organic molecules by cellular respiration/fermentation

Question 9

Saprobes/parasites

Answer 9

saprobes- free living mo that feed on organic detritus from dead organisms
parasites- ordinarily derive nutrients from cells or tissues of living host

Question 10

essential nutrients

Answer 10

CHONPS

Question 11

diffusion and the three types

Answer 11

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

Question 12

endocytosis

Answer 12

substances transported do not physically pass through but are carried into the cell by being enclosed/engulfed by the membrane.

Question 13

phagocytosis

Answer 13

amoeba and certain white blood cells ingest cells or large solid matter by this process

Question 14

pinocytosis

Answer 14

liquids, such as oils or molecules in solution enter the cell through this process

Question 15

binary fission

Answer 15

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)

Question 16

septum formation

Answer 16

during binary fission, the creation of the dividing wall between the two cells

Question 17

After binary fission, both daughter cells are_______

Answer 17

identical

Question 18

lag phase in bacterial growth

Answer 18

relatively flat period on the graph when the population appears not to be growing or is growing at less than the exponential rate.

Question 19

cause of lag phase in bacterial growth

Answer 19

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

Question 20

exponential, or log, phase in bacterial growth

Answer 20

the cells reach a max rate during cell division during this period where it increases geometrically

Question 21

stationary phase in bacterial growth

Answer 21

when the population enters a period where cell birth/death rate are more or less equal

Question 22

cause of stationary phase in bacterial growth

Answer 22

cause dby the depletion of nutrients and o2 plus excretion of organic acids and other biochemical pollutants

Question 23

death phase in bacterial growth

Answer 23

self explanatory via name; as the limiting factors intensify, cells die at an exponential rate and unable to multiply. Speed depends on their resistance.

Question 24

turbidity

Answer 24

indicator of cell growth in solution, identifiable as a cloudy appearance.

Question 25

Greater the turbidity, the _____ population size

Answer 25

Larger