Chapters 6, 5, 8 Flashcards
What does Growth mean when talking about bacteria cells?
increase in number
not size
What 3 things are the Cardinal Temperatures of Bacterium?
- Minimum Temperature
- Optimum Temperature
- Maximum Temperature
(temps they can reproduce at)
Do freezing temps denature bacteria, if so what does it denature, if not, what do cold temps do to bacteria
freezing bacteria does Not denature bacteria.
Freezing inhibits growth but once they are no longer frozen they begin reproducing again
What do you call bacteria that loves the cold temps?
Psychrophiles
What is the most common type of bacteria, the type we’d probably get sick from?
Mesophiles
Name the bacteria that love hot temps (not extreme hot hot temps)
Thermophiles
Name the bacteria that love EXTREMELY HOT HOT temps
Hyperthermophiles
What 3 things could very high temperatures denature in bacteria?
- enzymes
- ribosomes
- membranes
Around what temperature in F would be considered the “Danger Zone” where rapid growth of bacteria and sometimes production of toxins takes place within food?
between ~60 degrees F and ~120 degrees F
Who has more genes, humans or rice?
rice (almost double our gene count)
In general, are Hypotonic environments harmful to bacteria?
Osmotic Pressure
No
What happens to bacteria in a hypertonic solution?
plasmolysis
(shriveling, pulling away from cell wall caused by loss of water through Osmosis)
inhibits bacterial growth
Some bacteria can survive high osmotic pressure by increasing the solute concentration of their _________
cytoplasm
What is the name of the type of bacteria that can WITHSTAND high osmotic pressure exerted by salt?
(hypertonic)
Halotolerant
Name 3 ways we use hypertonic environments to preserve food
- Drying (ex: dried fruit)
- Salting
- Sugaring
What do Halophilic bacteria REQUIRE to survive?
high concentrations of salt
Bacteria that live at High or Low pH have mechanisms to keep the pH of their cytoplasm around _______
neutral
Different bacteria types have different Oxygen requirements.
True or False?
true
Where is the highest concentration of oxygen found in a lab tube, at the top or at the bottom?
highest O2 concentration at the top
What is the most temperature sensitive part of a bacterial cell? (which will denature first?membrane, enzymes, or ribosomes?)
- enzymes are most temperature sensitive
- then the membrane will melt
- 3rd the ribosomes will denature
When you slow the growth of bacteria by lowering temps to freezing but don’t kill it, this is called ______ __________
growth inhibition
All human pathogens are which type of bacteria (pertaining to reproduction in temperatures)?
Mesophiles
What type of bacteria spoil our food?
remember when you refreeze previously thawed food
Psychrotrophs
How come we can still get sick from food that has gone bad if we cook it at high temps, shouldn’t that kill the microbes?
toxins produced by the bacteria are not heat sensitive so they are still in meat after it’s cooked
Halotolerant orgnisms have pumps that help control the amount of salt and water in their cells.
true or false?
true
What is the difference between obligate aerobes and obligate anaerobes?
obligate aerobes: require O2, gather at the top of tube (cannot do anaerobic or fermentation)
obligate anaerobes: are poisoned by O2, so they gather at bottom of tube (can only grow in complete absence of O2 molecules)
What are the characteristics of a facultative anaerobe?
can live in the absence or presence of Oxygen
Which type of “anaerobes” can do anaerobic, aerobic, and fermentation process depending on the O2 availability and the materials available for fermentation? (they can use O2 if it’s present but can also use the other pathways when it’s not)
Facultative Anaerobes
more found toward top of tube but also dispersed throughout
Name the “anaerobe” that can live (but grows poorly) in O2, but is much happier in anaerobic conditions. This “anaerobe” does not use Oxygen for growth, but tolerates it’s presence.
Aerotolerant anaerobe
evenly dispersed throughout tube
What is a Microaerophile?
needs Oxygen for growth (aerobic pathway) but are poisoned by high concentrations of Oxygen
Does Oxygen have the ability to be toxic sometimes?
yes
Oxygen reacts with other molecules in the cell to produce _____ forms of oxygen. (ex: Hydrogen peroxide, superoxide radical, etc.)
toxic
Enzymes are used to ________ active oxygen compounds.
ex: Vitamin C, Vitamin E, Catalase, etc.
detoxify
What’s the main “ingredient” in a bacterial cell?
don’t overthink it
water
What are the 4 “Building blocks of Life”?
- Carbohydrates
- Fats/Lipids
- Proteins
- Nucleic Acids
List the main elements used in living cells
(CHONPS, CHNOPS)
(make up 96% of Dry weight of cells)
- Carbon
- Hydrogen
- Oxygen
- Nitrogen *
- Phosphorus *
- Sulfur
(limiting nutrients * )
Name 3 limiting Nutrients discussed in class
- Nitrogen *
- Phosphorus *
- Potassium *
What is the name given to the elements/minerals found in tap water in pretty large amounts?
Trace elements
What do you call something that makes it’s own glucose?
What do you call something that takes in glucose from it’s environment?
Autotroph= makes it's own glucose Heterotroph= takes in glucose from environment
Give the name of the process of a Chemosynthetic organism that obtains energy from the oxidation of inorganic compounds (rocks)
(it is an autotroph)
Chemolithoautotrophic processes
Glucose is involved in the synthesis of Nucleotides/Nucleic Acids and also the synthesis of the major protein building blocks, _____ _____
amino acids
You need Glucose to do Glycolysis which is an anaerobic process.
true or false
true
- Chromosome divides
- septum grows between cells
- the cells separate
what is being described above?
Binary Fission
How many Chromosomes does a bacterial cell begin with?
1 chromosome
What is the formula for finding the number of bacteria in a population after a given amount of time has elapsed?
(# you start with) x (2^n) = total number of cells in the population after elapsed time
n= number of generations
Name and discuss the stages of a simple bacterial growth curve
(4 phases)
- Lag phase: barely any growth
- Exponential growth phase (rapid growth, overnight)
- Stationary Phase (plateau)
- Death Phase
What is a limiting Nutrient?
a nutrient that is in short supply that will be exhausted first which then limits the growth
What does a molecule HAVE to have to be considered organic?
Carbon backbone
and they almost always have C-H bonds
What are almost all inorganic molecules lacking that organic molecules have?
Carbon
an acid solution has an excess of which type of ions?
H+ (Hydrogen Ions)
A Base (or an alkaline) solution has an excess of which type of ions?
OH- (Hydroxide)
If acids are H+ donors, then bases are H+ _________
acceptors