Microbiological growth and control Flashcards
What are phototrophs?
organisms that use sunlight as energy
what is photosynthesis?
turning sunlight into glucose
What are 3 types of phototrophs?
plants, algae, and cyanobacteria
what do plants, algae, and cyanobacteria all have in common?
all have chlorophyll
what is chlorophyll?
capturing molecule
what is NADH?
coenzyme that contains energy, originally stored in glucose through aerobic respiration. this energy gets transfrred into ATP
What is chemosynthetics?
using chemical compounds for energy
what are two types of chemosynthetics?
chemoautotrophs and chemoheterotrophs
what are chemoautotrophs?
they use inorganic compounds for energy and Co2 for their carbon source. mostly aquatic organisms
can chemoautotrophs or chemoheterotrophs be pathogenic?
chemoautotrophs
what are chemoheterotrophs?
require organic compounds for both energy and carbon
what chemical components do chemoheterotrophs use for E?
Carbs, protiens, lipids, vitamins (fungi), and inorganics
What do chemoheterotrophs do with carbs?
they easily convert them into glucose for energy
what do Chemoheteotrophs do with protien?
it is broken down into amino acids first and then to make specific protiens
What do bacteria make their fat from?
sugar
do bacteria need vitamins?
no
what inorganics do chemoheterotrophs use?
S, FE, Mg, Ca, Na, K
why do bacteria need enzymes for digestion?
They use enzymes o break their food into smaller particles before they can ingest them
how do bacteria use their enzymes?
some secrete their enzymes into their surroundings while others put enzymes into their slime layer
what are two ways a eukaryote can ingest food?
diffusion and phagocytosis
what are two organisms that use phago cytosis?
amoebas and leukocytes
what are psychrophiles?
organisms that do best at temperatures below 20C
what types of bacteria can you find in psychrophiles?
refrigerator spoilage
how many pathogens can be found in psychrophiles?
few
what are mesophiles?
organisms that do best at room temp-body temp (25-37C)
what temperature category do most bacteria fall into?
mesophiles
what temperature catagory can most of the pathogenic organisms be found?
mesophiles
what are thermophiles?
organisms that do best at 40C or higher
what kind of bacteria can be found in thermophiles?
some food spoilage bacteria.
what temperature category can survive pasteurization?
thermophiles
what does heat do to bacteria?
it denatures their enzymes
what are 3 types of heat used to kill bacteria?
Dry heat, Moist heat, pasteurization
what does dry heat do?
it dessicates and kills but takes a long time and many endospores are resistant
what are two ways to use moist heat?
boiling and autoclave (steam)
what should the temperature be and for how long should an autoclave run for sterilization?
250F for 15-30 min
what is a con with boiling?
may take hours to kill spores
what are four types of pasteurization?
flash pasteurization, bulk or vat pasteurization, ultra pasteurization, and ultra high temp pasteurization
what is pasteurization?
the use of high heat for short periods of time
what is flash pasteurization?
used for milk and juice for 10-20 seconds at 70-80 degrees
what is bulk or vat pasteurization?
used for wine for 30 minutes at 60-70C
what is ultra pasteurization?
138C for 2 seconds
what is ultra high temp pasteurization?
138-150C for 1-2 seconds
what are obligate anerobes?
cannot live in oxygenated environments, some will produce endospores to survive
what are 3 types of obligate anerobes?
clostridium botulinium, clostridium pefringes, and clostridium tetani
what are obligate aerobes?
they require O2 to grow
what is an example of an obligate aerobe?
pseudomonas aeruginosa
what are facultative anaerobes?
can grow with or without o2
are their facultative aerobes?
no
what do facultative anaerobes prefer?
o2
where will you find the most pathogens? aerobes, anaerobes, or facultative anaerobes?
facultative anaerobes
what are two examples of facultative anaerobes?
E. Coli, Salmonella
what pH level do bacteria do best at?
neutral to slightly acidic (5-7.5)
what will organisms do to combat competitors?
produce acids to slow their growth
What will happen to cells if their environment is hypertonic?
they will crenate
what type of environment do bacteria enjoy? hyper, hypo, or isotonic?
isotonic
how much salt do bacteria enjoy?
about 0.85%
what concentration of salt is sea water?
3.5%
what does hypertonic mean?
less osmotic pressure outside the cell
what does hypotonic mean?
less osmotic pressure inside the cell
What are the 6 ways we can control bacterial growth?
Manipulating Energy, nutrition, temperature, oxygen, pH, osmotic pressure
What are the five phases of the bacterial growth curve?
Lag, log, stationary, death, and dormant
What is the lag phase?
Time from inoculation to growth, the introduction period
What is the log phase?
Bacteria growing and reproducing at a constant and rapid rate. Growth phase.
What is the stationary phase?
Numbers stay the same for the most part. Exaughstion of nutrients equal the amount of waste products
What is death phase?
Rapid death and decrease in number because the nutrients have been exaughsted
What is the dormant phase?
Few bacteria will survive either with a spore or lower their metabolic rates to bare minimum. Never hit 0
What bacterial growth stage are antibiotics most effective during?
Log phase
How long does your immune system take to build up?
7-10 days
What is catabolism?
Energy yeilding reactions
What is the basic energy yielding nutrient?
Glucose
What is the nutritional value of glucose?
4kcal/g
What are the two main routes of getting energy?
Fermentation and respiration
What is the chemical equation that takes place during fermentation?
Glucose + 2ATP = waste product (lactic acid, alcohol, etc) + 4ATP
What is the net amount of ATP generated from fermentation?
2 ATP/glucose
What uses fermentation?
Yeasts and some bacteria
What uses respiration to generate energy?
Bacteria
What is the chemical equation for respiration for ATP?
Glucose + 2ATP=Co2 + H2O + 40ATP
What is the net amount of ATP respiration can generate?
38
What can use S or No3 or other inorganic compounds to remove H from glucose?
Anaerobic bacteria
What is anabolism?
Energy requiring reactions, manufacture of materials required for cell function or structure
