Get 2 days of premium access
Study Guides (370,000)
US (220,000)
UMD (10,000)
BSCI (1,000)
Buchner (10)
Study Guide

[BSCI 223] - Final Exam Guide - Everything you need to know! (109 pages long)


Department
Biological Sciences Program
Course Code
BSCI 223
Professor
Buchner
Study Guide
Final

This preview shows pages 1-3. to view the full 109 pages of the document.
UMD
BSCI 223
FINAL EXAM
STUDY GUIDE

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Lecture 10: Growth and Death
Chapters 6 and 9
Microbial Replication
Binary fission
o Primary mode of bacterial replication
o Most often used
o Produces two cells of approximately the same size
Budding
o Mode of yeast replication
o Single cell eukaryotic cells
o One cell that buds off of the mother cell
Filamentous growth
o Mode of fungal growth
o Growth in different directions
o Some can branch off
o Increase in overall size of organism
Binary Fission
In bacteria usually 1 circular chromosome
Polarity
Exponential growth: product of previous replication to determine number of
next group of cells
Generation time
The time required for a population to double in number (doubling time)
Generation time should be the same for each set of replication
Counting cultures
Count number of cells within the grid slide
Count cells how much bacterial contamination is in a product
Drawbacks: must have immobile bacteria, bacteria is really small (must stain
them)
Dilution series
A 1:10 dilution each dilution goes up by a dilution factor of 10
Unit: cells/mL
One colony = one cell 0.1 mL is approximately 65 cells
o 650 cells per mL
o 1000 = total number of cells/mL
Plating is a great way to see how many living cells
Spectrophotometer
Turbidity of absorbance of culture
Has a light source tube in middle, and a light sensitive detector
Bacteria will refract the light more refraction, the more cells
Doesn’t tell you the different in live/dead cells, doesn’t tell you the number,
but just an absorbance reading (this is not the same as how many living cells
are present)
Phases of growth for batch culture
Lag phase
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

o Synthesis of primary metabolites (necessary for growth)
o Adapted to environment (different between rich and minimal
environments)
o Length depends on type of bacteria
o No cell division
Exponential (log) phase
o Cells are actively dividing
o Rapid increase in cell numbers
Stationary phase
o Lack of available nutrients prohibits growth
Cells ran out of nutrients
o No net increase in numbers
o Cell division rate = cell death rate
Death phase
o Decrease in viable cell numbers
o Death > doubling
o Senescence
Decrease in metabolic activity
o Not in all cultures
o Amount of time to get to death phase will vary all depends on
culture (not all will reach death phase)
Log Scales
Useful when measuring rapid changes
Each trick is 10x different
o 102 = 100
o 103 = 1000
o 104 = 10000
Never gets to 0
Calculating doubling time
CFU = colony forming units
Doesn’t matter what set of numbers you take, as long as they are double the
time away
Growth Condition comparison
Steeper the slope, the faster the doubling time
o Represents a faster replication time
Double Y-axis charts
Two Y-axis will have different units
X-axis is always the same
Allows you to get CFU/mL reading and what the OD reading is
Between cell divisions: synthesis
DNA
Ribosomes
Cell wall
Cell membrane (cytoplasmic and outer)
Proteins (metabolism/transport)
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version