Chapter 9 Nutrition and Growth

Question 1

What is nutrition in microbiology?

Answer 1

The process of acquiring and using nutrients for microbial growth.

Question 2

What are nutrients?

Answer 2

Substances organisms need for energy and growth.

Question 3

What is an essential nutrient?

Answer 3

A nutrient an organism must obtain from the environment.

Question 4

What are macronutrients?

Answer 4

Nutrients needed in large amounts (C, H, O, N, P, S).

Question 5

What are micronutrients?

Answer 5

Nutrients needed in small amounts (e.g., zinc, iron).

Question 6

What are trace elements?

Answer 6

Micronutrients needed in extremely small amounts.

Question 7

What is an inorganic nutrient?

Answer 7

A nutrient without carbon-hydrogen bonds (e.g., CO₂, H₂O).

Question 8

What is an organic nutrient?

Answer 8

A nutrient containing carbon and hydrogen (e.g., glucose).

Question 9

What is a heterotroph?

Answer 9

An organism that gets carbon from organic sources.

Question 10

What is an autotroph?

Answer 10

An organism that uses CO₂ as a carbon source.

Question 11

What is a phototroph?

Answer 11

An organism that uses light as an energy source.

Question 12

What is a chemotroph?

Answer 12

An organism that uses chemicals for energy.

Question 13

What is a photoautotroph?

Answer 13

Uses light for energy and CO₂ for carbon.

Question 14

What is a chemoorganic autotroph?

Answer 14

Uses organic molecules for energy and CO₂ for carbon.

Question 15

What is a chemolithoautotroph?

Answer 15

Uses inorganic compounds (e.g., iron, sulfur) for energy and CO₂ for carbon.

Question 16

What is a methanogen?

Answer 16

An archaea that produces methane from H₂ and CO₂.

Question 17

What is a chemoheterotroph?

Answer 17

Gets energy and carbon from organic molecules.

Question 18

What is aerobic respiration?

Answer 18

Energy production using oxygen.

Question 19

What are saprobes?

Answer 19

Organisms that feed on dead organic matter.

Question 20

What are parasites?

Answer 20

Organisms that live in/on a host and cause harm.

Question 21

What does obligate mean in microbiology?

Answer 21

Requires a specific condition to survive.

Question 22

What does facultative mean?

Answer 22

Can adapt to different conditions.

Question 23

What does opportunistic mean?

Answer 23

Normally harmless but can cause disease if given the chance.

Question 24

What are pathogens?

Answer 24

Disease-causing microbes.

Question 25

What is diffusion?

Answer 25

Movement of molecules from high to low concentration.

Question 26

What is osmosis?

Answer 26

Diffusion of water across a membrane.

Question 27

What does permeable mean?

Answer 27

Allows certain substances to pass through.

Question 28

What is an isotonic environment?

Answer 28

Solute concentration is equal inside and outside the cell.

Question 29

What is a hypotonic environment?

Answer 29

Lower solute outside; water enters the cell.

Question 30

What is a hypertonic environment?

Answer 30

Higher solute outside; water leaves the cell.

Question 31

What does turgid mean?

Answer 31

Swollen due to water intake (common in plant cells).

Question 32

What is facilitated diffusion?

Answer 32

Passive transport using proteins.

Question 33

What is specificity in transport?

Answer 33

Transport proteins are specific to certain substances.

Question 34

What is saturation in transport?

Answer 34

All transport proteins are in use.

Question 35

What is competition in transport?

Answer 35

Molecules compete for transport proteins.

Question 36

What is active transport?

Answer 36

Movement of substances using energy (ATP).

Question 37

What is group translocation?

Answer 37

Substance is modified as it enters the cell.

Question 38

What is endocytosis?

Answer 38

Cell engulfs material into a vesicle.

Question 39

What is phagocytosis?

Answer 39

"Cell eating" – engulfing solid particles.

Question 40

What is pinocytosis?

Answer 40

"Cell drinking" – engulfing liquid.

Question 41

What is minimum temperature?

Answer 41

Lowest temperature allowing growth.

Question 42

What is maximum temperature?

Answer 42

Highest temperature allowing growth.

Question 43

What is optimum temperature?

Answer 43

Temperature at which growth is fastest.

Question 44

What is a psychrophile?

Answer 44

Loves cold (0–15°C).

Question 45

What is psychrotolerant?

Answer 45

Can grow in cold but prefers moderate temps.

Question 46

What is a mesophile?

Answer 46

Prefers moderate temperatures (20–45°C).

Question 47

What is a thermophile?

Answer 47

Prefers hot environments (45–80°C).

Question 48

What is an extremophile?

Answer 48

Thrives in extreme conditions.

Question 49

What is an aerobe?

Answer 49

Requires oxygen to grow.

Question 50

What is an oxygen radical?

Answer 50

Toxic by-products of oxygen metabolism.

Question 51

What is an anaerobe?

Answer 51

Cannot use or tolerate oxygen.

Question 52

What is a microaerophile?

Answer 52

Needs oxygen in low amounts.

Question 53

What is an aerotolerant organism?

Answer 53

Tolerates but doesn’t use oxygen.

Question 54

What is a capnophile?

Answer 54

Requires high CO₂ levels.

Question 55

What is an acidophile?

Answer 55

Prefers acidic environments.

Question 56

What is an alkalinophile?

Answer 56

Prefers basic (alkaline) environments.

Question 57

What is an osmophile?

Answer 57

Thrives in high solute (sugar/salt) conditions.

Question 58

What is a halophile?

Answer 58

Prefers high salt conditions.

Question 59

What is a barophile?

Answer 59

Thrives under high pressure.

Question 60

What is symbiosis?

Answer 60

Close relationship between two organisms.

Question 61

What is mutualism?

Answer 61

Both organisms benefit.

Question 62

What is commensalism?

Answer 62

One benefits, other is unaffected.

Question 63

What is parasitism?

Answer 63

One benefits, other is harmed.

Question 64

What is synergism?

Answer 64

Two microbes work together more effectively.

Question 65

What is antagonism?

Answer 65

One microbe harms or inhibits another.

Question 66

What is quorum sensing?

Answer 66

Cell-to-cell communication based on population density.

Question 67

What is binary fission?

Answer 67

Asexual reproduction where a cell splits in two.

Question 68

What is generation time?

Answer 68

Time for a population to double.

Question 69

What is a growth curve?

Answer 69

Graph showing population changes over time.

Question 70

What happens in the lag phase?

Answer 70

Cells adjust to environment, no division yet.

Question 71

What happens in the log (exponential) phase?

Answer 71

Cells divide rapidly.

Question 72

What happens in the stationary phase?

Answer 72

Growth = death rate; resources deplete.

Question 73

What happens in the death phase?

Answer 73

Cells die faster than they divide.

Question 74

What does turbid mean?

Answer 74

Cloudy appearance indicating growth in broth.

Question 75

What is a chemostat?

Answer 75

Device that maintains constant growth conditions.

Question 76

What is direct cell count?

Answer 76

Counting all cells, alive or dead.

Question 77

What is a cytometer used for?

Answer 77

Measuring and counting cells.