How many elements are essential for life?
25 are essential, from bacteria to humans
What are Macro-nutrients? (needed in larger quanitites)
Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur, Phosphorus, Potassium, Magnesium, Calcium
(C,H,O,N,S,P,K,Mg,Ca)
What are micronutrients? (needed in lesser quantities)
- they are needed for enzymes
- DNA requires Mg and Zn (magnesium and zinc)
- others include Mn, Zn, Mo, Ni, Cu, Co, B, F, I, Fe, Se, Si, Sn, V
When someone is missing a certain quantity of an element, they have a
deficiency
Where do most microbes get their energy from?
From both organic and inorganic sources
In the 1960s, why were women dying?
They were dying because the tampons, at that time, absorbed too much iron which caused toxic shock syndrome.
When a person has the correct diet, they do not need
extra supplements, the body will excrete the extra nutrients/minerals because a person with the correct diet will have all the essential nutrients and vitamins.
The average cell has
70% water
What is aerobic respiration?
When water is reduced into oxygen
What is a major micro molecule?
water
What is a major macro molecule?
protein
Where is chemical composition the most similar?
bacteria, fungi, and protozoa
-depends on the species (but will always have something different)
What is metabolism?
the ability to break down molecules and get energy (which comes from sunlight)
What are the characteristics of photoautotrophs?
energy source: sunlight
carbon source: CO2
photosynthetic organisms: algae, plants, cyanobacteria
What are some characteristics of chemoautotrophs?
energy source: simple inorganic molecules
methanogens. deep sea vent bacteria
What are some characteristics of photoheterotrophs?
energy source: sunlight
purple and green
photosynthetic bacteria
do NOT use CO2
What are some characteristics of chemoheterotrophs
energy source: metabolic conversion of nutrients from other organisms
protozoa, fungi, many bacteria, and animals
What is a saccrobe?
an organism with the ability to metabolize the organic matter of dead organisms
fungi, bacteria, (decomposers)
What is a parasite?
an organism that utilizes the tissues and fluids of a host
various parasites and pathogens: bacteria, fungi, protozoa, animals
Who produced nitrate?
the Germans
Inside legumes, there are nodules that do
nitrogen fixation - which is the process of N2 is changed by nitrogenase into NH3, Rhizobium
Why is phosphorus important?
It is important for phosphate, PO4
Is important for metabolism, more phosphate = more energy
Where does phosphate come from?
soil
What is mycorrhiza?
can get phosphate deep, deep, deep, in soil
Mycelia
Plants share ____________ to get phosphate
fungi filaments
What is sulfur important for?
Cysteine, which is in the structure of proteins and found in disulfide bonds
Hemoglobin requires what?
Iron
The Black Death was caused by
Yersinia pestis
All cells have a
semi-permeable membrane
Bacteria have different mechanisms in which they
take in food, food is in the form of chemicals
Osmotic pressure is?
the movement of water through a membrane
Isotonic solution
where the amount of solutes are in equilibrium from inside and outside the cell
Hypotonic solution
higher concentration of solutes are present in the cell; water will go into the cell
low to high concentration of solutes
Hypertonic solution
water moves from inside the cell to the outside of the cell
(moves from low to high concentration)
Plasmolysis
barophiles are
bacteria that can withstand high pressure
Cells need
glucose; when it is broken down, it turns into ATP
Exoenzymes are
enzymes that are exported out of the cell to digest carbohydrates and proteins
The cell membrane is
hydrophobic
What do cells have that allow for proteins, carbs, and solutes to enter?
protein channels
What may occur when solutes pass through the protein channels?
they may become modified
- protein (enzymes) can chemically modify product/substrate into something else
active transport is
when solutes need to be pushed into the cell
ex. insulin pushes glucose into the cell
passive transport is
when solutes flow through the cell
- no use of energy
What can pass through the hydrophobic membrane?
testosterone
Ion channels are
channels that can allow potassium, magnesium, chloride, and calcium into the cell.
channels can open and close
Phagocytosis is
when a cell engulfs a particle to consume
eats solids, is a method of active transport
Macrophages are
white blood cells that engulf bacteria, viruses, pollen, etc.
Pinocytosis is
when a cell absorbs oil and liquid
drinks liquids, also a method of active transport
What does microbial ecology focus on
ways that microorganisms deal or adapt to various environmental factors
What are the main factors that affect survival and growth?
temperature, gases, pH, radiation, osmotic pressure, hydrostatic pressure, other microorganisms
What microorganism can tolerate the stomach's pH of 2-3
H.pylori
Bacteria that grow in -15 °C to 15 °C are
psychrophiles
Bacteria that grow in 10 °C to 50 °C are
mesophiles
most bacteria grow here
Bacteria that grow in 45 °C to 80 °C are
thermophiles
Bacteria that grow over 80 °C are
hypothermophiles
Facultative thermophiles are
bacteria that can tolerate higher and cooler temperatures
DNA polymerase
enzyme that replicates DNA
Thermos aquaticus (TAQ enzyme)
PCR technique
Halophiles are
bacteria that can survive high salt concentration
Listeria monocytogenes
is found in dairy products, killer of people in Mexico and RGV
comes from cheese that has not been pasteurized
Pasteurization
kills bacteria, the U.S. requires that all imported cheese must be pasteurized
Salmonella
can grow at low temperatures in the fridge
from chicken
S.aureus
grows at 4 °C - are opportunist
highly resistant to all antibiotics
likes to grow on 7% to 8% salt
can contaminate chorizo
Capnophiles are
bacteria that grow at 3-10% concentrations of CO2
- neisseria, brucella, and streptococcus pneumonia
Oxygen concentration of air is about
20%
CO2 concentration is about
0.003% (3,000 ppm)
The atmospheric gases that influence the growth of microorganisms the most are
oxygen and carbon dioxide
singlet oxygen (extremely reactive)
O2
superoxide ion
-O2
hydrogen peroxide molecule
H2O2
hydroxyl molecule
OH-
most bacteria, fungi, algae, and protozoa are considered
aerobes
bacteria that can tolerate minimal amounts of oxygen are
- Ex. E.coli
microaerophillic
aerobic bacteria will grow at the
top of the liquid in a test tube
microaerophillic bacteria will grow
right below the surface, remains near the top
anaerobic bacteria will grow
towards the bottom of the tube, with minimal oxygen
Facultative anaerobes will
grow all over
When bacteria split into two, keeping the same genetic material
binary fission
Typically, bacteria will multiply every
20-25 mins, under optimal conditions
which bacteria reproduces every 10–30 days?
mycobacteria leprae, tuberculosis
the phase where there are very few cells
lag phase
phase where cells are live and being to reproduce
Exponential or log phase
phase where there are many live cells, few dead cells
stationary phase
phase where cell death occurs
death phase
the time needed for a bacterial population to double in number
generation time
pertroff hausser counter was
a device that counted bacteria using squares under the microscope
Coulter counter was
an electronic counter that counted dead and live bacteria