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BSC 160 Study Guide - Gums, Antibiotics, Clostridium


Department
Biological Sciences
Course Code
BSC 160
Professor
All

Page:
of 7
UNIT 3 STUDY GUIDE:
MICROBIAL NUTRITION, GROWTH & CULTURE
NUTRITION – 6 QUESTIONS
1. Two types of cell activity
Metabolism (all chemical reactions that maintain life)
Reproduction
2. Two types of metabolic reactions; precursors & by-products
Catabolic (break down larger molecules) provide building blocks and energy for
anabolic
Energy produced
-breaking down starch simple
Break down sugar in CO & H20
Anabolic building up larger molecules (biosynthesis)
Require energy uniting amino acids into proteins
6 Elements make up 99% of bacterium weight
Oxygen 74%
Carbon 12%
Hydrogen 10%
Nitrogen 3%
Phosphorus 0.6%
Sulfur 0.3%
OCHNPS
3. Definition of macronutrient-Elements needed in large amounts-structural components
(walls, membranes, chromosome) - enzymes
A. What are the macronutrients needed by bacteria (must be available in microbe’s
environment) –Oxygen and Hydrogen…..needed by most bacteria supply 1%-most require
structural components/enzymes(walls, membranes, chromosomes)
B. Sources of macronutrients
Carbon
-50% major element, non-photosynthetic bacteria require organic carbon
-photosynthetic organisms use CO2
-simple sugars – most easily utilized
Nitrogen- 2nd most abundant 12% (ammonia/nitrate) inorganic
Phosphorous: needed by cell for synthesis of nucleic acids/phospholipids
-important energy compound ATP (membranes, nucleic acids, energy)
Sulfur: 2 Roles: amino acids cysteine and methionine/present in vitamins
-inorganic sulfate
Potassium/Megnesium
Calcium/Sodium: not required by all.
-reflect habitat, ex—marine bacteria require sodium (salt water)
C. Why are they needed : for structural components and enzymes
4. What are micronutrients “trace elements”
Required in smaller amounts
-critical to cell function
-metals (magnesium/iron)
5. What are growth factors organic/required in very small amounts
-Vitamins, amino acids, purines, pyrimidines
-vitamins most commonly needed growth factors
-function as component of enzymes (cell wont thrive without)
6. What is cellular energy
A. How is it obtained (require energy—chemically w/ electron used to form new chemical
bonds
i. non-photosynthetic organisms: Nonphotosyntehtic – energy by breaking bonds in
chemical compounds during catabolism
ii. photosynthetic organisms
photosynthetic bactera obtain some energy from sunlight
B. How is it stored in cells captured and stored by little chemical “batteries”
Battery: molecule called Adenosine Triphosphate, ATP
-capture/donate electrons to cellular reactions
GROWTH – 6 QUESTIONS
1. Bacterial reproduction –binary fission into 2 identical daughter cells
A. Define generation time :length of time it takes cells to elongate and divide (doubling
time)
B. Growth curve: microbial populations develop under stab condition
i. Identify the 4 phases in a graphic display
Lag Phase
One hour - several days
Period of adjust to new conditions
oNo cell division
oPopulation does not increase
oBacteria adapting to new environment
Phase of intense metabolic activity
oEnergy spent on anabolic activities
o‘Tooling-up’
oMaking new enzymes needed to use nutrients in new environment
Individual organisms grow in size
Log phase
Cell division begins
Generation time becomes constant
Period of rapid growth with a big increase in population
Cells are very susceptible to adverse environmental factors
oRadiation
oAntibiotics
Stationary phase
Population stabilizes & growth rate slows down