chapter 6.2

Question 1

forms of oxygen that are highly reactive and behave like oxidizing agents, stealing electrons from chemicals

Answer 1

toxic forms of oxygen

Question 2

when a molecule loses electrons during a chemical reaction

Answer 2

oxidization

Question 3

when a molecule gains electrons during a chemical reaction

Answer 3

reduction

Question 4

a molecule that strips electrons from other molecules

Answer 4

oxidizing agent

Question 5

four toxic forms of oxygen

Answer 5

• singlet oxygen
• superoxide radical
• peroxide anion
• hydroxyl radical

Question 6

an enzyme that some aerobes have that converts Hydrogen Peroxide into water and oxygen

Answer 6

catalase

Question 7

hydrogen peroxide naturally converts to what unless there is catalase present

Answer 7

peroxide anions or hyrdroxyl radicals

Question 8

protect against oxidizing agents from stealing electrons through donating electrons to oxidizing agents which quenches their thirst for electrons

Answer 8

antioxidants

Question 9

nitrogen is needed to synthesize

Answer 9

proteins and nucleic acids

Question 10

where is nitrogen found

Answer 10

• amino group of amino acids
• nucleotides that make up DNA/RNA

Question 11

low levels of lack of nitrogen do what

Answer 11

limit growth of microbe since DNA and proteins are required to grow in size or reproduce through cell division

Question 12

needed for synthesis of nucleic acids and ATP

Answer 12

phosphorous

Question 13

energy currency in cells

Answer 13

ATP

Question 14

phosphate backbone of DNA

Answer 14

nucleic acids

Question 15

element found in some amino acids

Answer 15

sulfur

Question 16

sulfur allows for

Answer 16

3D structures and protein folding

Question 17

elements that are required in very small amounts, but still essential

Answer 17

trace elements

Question 18

organic chemicals that cannot be synthesized by certain microorganisms that boost growth

Answer 18

growth factors

Question 19

important physical factor in microbial growth because it affects protein structure and plasma membrane structure

Answer 19

temperature

Question 20

protein that unfolds and works uncorrectly

Answer 20

denaturing

Question 21

if the temp is too low the plasma membrane becomes

Answer 21

too rigid/fragile, close together and will shatter

Question 22

if temp is too high the plasma membrane

Answer 22

becomes too fluid like, moves away from eachother

Question 23

generally grow best below 15 degrees and are found in cold water ice and snowfields, cannot infect humans

Answer 23

psychrophiles

Question 24

generally grow best between 20-40 degrees celsius and are found in most environments, pathogenic to humans

Answer 24

mesophiles

Question 25

this bacteria grows in extreme heat which include boiling water of hot springs

Answer 25

thermophiles/hyperthermophiles

Question 26

how can thermophiles/hyperthermophiles survive in their envrionment

Answer 26

avoid denaturing and damage as they often have extra hydrogen and covalent bonds that maintain structure

Question 27

the lowest temp the bacteria will grow at, growth is slow

Answer 27

minimum temp

Question 28

highest temp the bacteria will grow at, growth is slow

Answer 28

maximum temp

Question 29

growth of bacteria is the fastest at this temp

Answer 29

optimal temp

Question 30

what happens to the bacteria cell when it is at a temp higher than its maximum temp

Answer 30

• plasma membrane melts causing vital chemicals to leak out
• proteins denature or unfold, proteins not native in shape will not work

Question 31

what happens to a bacteria cell when it is at a temp lower than it minimum temp

Answer 31

• plasma membrane becomes rigid and shatters
• metabolism slows down, reproduces slows

Question 32

microorganisms that grow in a narrow pH range that is close to neutral

Answer 32

neutrophiles

Question 33

thrive in environments with a pH less than 5

Answer 33

acidophiles

Question 34

live in alkaline soils and water up to pH 11.5

Answer 34

alkalinophiles

Question 35

pH below 7

Answer 35

acid

Question 36

pH above 7

Answer 36

basic

Question 37

movement of water across a semipermeable from high concentration to low concentration

Answer 37

osmosis

Question 38

solutions have low solute concentration or high water concentration compared to the inside of the bacteria cell, bacteria will burst

Answer 38

hypotonic

Question 39

solutions have high solute concentration or low water concentration compared to the inside of a bacteria cell, will shrink

Answer 39

hypertonic

Question 40

Biofilm functions:

Answer 40

1. allow bacteria to adhere to the environment or other bacteria better
2. sequesters or takes in additional water and nutrients
3. serves as a physical form of protection from other microorganisms or harmful toxins

(make microorganisms more harmful or pathogenic)

Question 41

how biofilm is produced

Answer 41

1. bacteria cells secrete quorum sensing molecules
2. quorum sensing molecules detect the presence of other individuals
3. quorum sensing molecules then activate genes involved in the production of biofilms
4. channels develop in biofilm that allow for the transport of water