MICROBIAL GROWTH
Terms
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- IN MICROBES, GROWTH =
- AN INCREASE IN CELLULAR COMPONENTS, LEADING TO AN INCREASE IN CELL SIZE
- WHAT DOES MICROBIAL GROWTH LEAD TO
- MICROBIAL GROWTH LEADS TO AN INCREASE IN CELL #
- IN MICROBIAL GROWTH, CELL SIZE INCREASES BY WHAT AMOUNT ( USUALLY)
- 2X THE ORIGINAL SIZE
- IN PROCARYOTES, MICROBIAL GROWTH OCCURS BY
- BINARY FISSION
- DEFINE BINARY FISSION
- BINARY FISSION IS AN INCREASE IN CELL SIZE ( USUALLY 2X)
- LIST THE 4 STEPS INVOLVED IN BINARY FISSION
-
---DNA ATTATCHES TO THE PLASMA MEMBRANE OF THE CELL AND IS REPLICATED
---(2) COPIES MOVE AWAY FROM EACH OTHER TO OPPOSITE ENDS OF THE CELL
---PM AND THE CELL WALL GROW INWARD IN THE CENTER OF THE CELL
---PM AND THE CELL WALL MEET TO SEPARATE CELL INTO TWO DAUGHTER CELLS THAT ARE GENETICALLY IDENTICAL - THE TIME IT TAKES TO COMPLETE BINARY FISSION ( PROCARYOTES MICROBIAL GROWTH) IS CALLED
- GENERATION TIME
- DEFINE GENERATION TIME
- THE TIME IT TAKES PROCARYOTES TO COMPLETE BINARY FISSION AKA THE DOUBLING TIME
- GIVE AN EXAMPLE OF A SHORT GENERATION TIME FOR BINARY FISSION OF PROCARYOTE CELLS
- LESS THAN 20 MINUTES....E-COLI AND STAPH
- MOST MICROBES GENERATION TIME IS ( IN BINARY FISSION OF PROCARYOTES)
- 1-3 HOURS IS THE AVG GENERATION TIME OF PROCARYOTES.
- GIVE AN EXAMPLE OF A LONG GENERATION TIME OF BINARY FISSION IN PROCARYOTES
- DAYS TO WEEKS ( MYCOBACTERIUM AND LEPRA=10 DAYS)
- IN A LAB,,,BACTERIA ARE GROWN IN A
- BATCH CULTURE
- DEFINE A BATCH CULTURE AND GIVE AN EXAMPLE
- A CLOSED CULTURE VESSEL EX. A TEST TUBE WITH A CAP
- IN MICROBIAL GROWTH, A BATCH CULTURE ( CLOSED CULTURE VESSEL SUCH AS TEST TUBE W/A CAP) NEEDS TO HAVE A SET VOLUME EX. 3.5 MLS OF NUTRIENT BROTH
- NOTE
- IN MICROBIAL GROWTH LIST SOME OF THE ENVIRONMENTAL CONDITIONS THAT MUST BE CONSTANT FOR GROWTH TO OCCUR
- AN INCUBATOR IS USUALLY USED,,,CONSTANT TEMP (98.6 F),CONSTANT LIGHT, SHAKING ETC
- A BATCH CULTURE CREATES
- A PREDICTABLE PATTERN OF GROWTH
- WHEN TALKING ABOUT BATCH CULTURES WHAT DOES THE TERM "VIABLE" MEAN
- VIABLE MEANS THAT THEY HAVE METABOLIC ACTIVITY, AND THEY'RE ABLE TO REPRODUCE
- WHAT IS THE FIRST PHASE AFTER AN INNOCULATION OF A BATCH CULTURE
- THE LAG PHASE
- WHAT HAPPENS TO THE CELL # DURING THE LAG PHASE
- LITTLE OR NO SIGNIFICANCE IN CELL # DURING THE LAG PHASE
- GIVE TWO REASONS WHY THE LAG PHASE OCCURS
-
CELLS ARE ADJUSTING TO THERE NEW ENVIRONMENT
THE CELLS ARE SYNTHESIZING NEW CELL COMPONENTS - WHAT DOES SYNTHESIZING NEW CELL COMPONENTS MEAN
- PREPARING TO DIVIDE
- ANOTHER REASON THAT THE LAG PHASE OCCURS IS BECAUSE CELLS ARE REPAIRING DAMAGE FROM....
- THE TRANSFER
- LIST (4) REASONS WHY A "LONG" LAG PHASE MAY OCCUR
-
---POOR TRANSFER TECHNIQUE CAUSED EXCESSIVE DAMAGE
---DRAMATIC CHANGE IN TEMP ( TRANSFER FROM A WARM TUBE TO A COLD ONE)
---DRAMATIC CHANGE IN MEDIUM( NUTRIENT BROTH TO A SUCROSE MEDIUM)
---THE CELLS MAY BE OLD - IN MICROBIAL GROWTH,,,THE PERIOD AFTER THE LAG PHASE
- EXPONENTIAL PHASE
- DEFINE THE EXPONENTIAL PHASE
- PERIOD OF MAXIMUM INCREAE IN CELL #
- CELLS ARE MOST UNIFORM IN THIS PHASE, BEST FOR STUDY
- EXPONENTIAL PHASE
- THIS PHASE OCCURS AFTER THE EXPONENTIAL PHASE, AND THERE IS NO SIGNIFICANT CHANGE IN CELL #
- THE STATIONARY PHASE
- WHY IS THERE NO CHANGE IN CELL # DURING THE STATIONARY PHASE
-
---CELLS HAVE NO METABOLIC ACTIVITY BUT DON'T DIVIDE
---A BALANCE BTWN CELL DEATH AND CELL DIVISION
--- - WHY DOES THE STATIONARY PHASE OCCUR
-
NUTRIENTS BECOME LIMITED ( THE GREATEST COMPETITION FOR NUTRIENTS IN THIS PHASE)
---WASTE BEGINS TO ACCUMULATE MAKING THE ENVIRONMENT INHOSPITABLE - DEFINE THE DEATH PHASE
- THE FINAL PHASE OF BATCH CULTURE, EXPONENTIAL DECREASE IN CELL #,,,THE OPPOSITE OF THE EXPONENTIAL PHASE
- WHY DOES THE DEATH PHASE OCCUR
- COMPLETE LACK OF NUTRIENTS, WASTE ACCUMULATES TO TOXIC LEVELS, AND KILLS THE CELLS