Growth And Metabolism

Question 1

What are the requirements for bacterial growth

Answer 1

carbon source
nitrogen source
essential nutrients eg vitamins
temperature
the right atmosphere
Inorganic ions, iron
The right pH
Water

Question 2

What type of carbon source do bacteria need

Answer 2

simple carbohydrates, sugars, proteins

Some organisms can fix CO2, by taking it out of the air and fixing it into an organic building block

Question 3

What type of Nitrogen source do bacteria need

Answer 3

protein, peptides and amino acids, DNA, Nitrates, ammonium salts

Some organisms can fix N2

Question 4

How do bacteria get their essential nutrients

Answer 4

some can synthesize all their needs

others need complex organic molecules, like blood or vitamins to grow this is from their human host

Question 5

What are fastidious bacteria

Answer 5

Hard to grow in a lab because they have complex molecules that are often from the human host

Question 6

What type of temperatures do bacteria typically grow the best in

Answer 6

At middle temperatures 20-40 degrees Celsius, called mesophiles

Question 7

What is the lowest temperature a bacteria can grow in

Answer 7

4 degrees Celsius in the fridge

Question 8

How does oxygen affect bacteria in aerobic organisms

Answer 8

it acts as a final electron acceptor in aerobic organisms

Question 9

What is the superoxide radical (O2-)

Answer 9

it is toxic and very reactive it needs to be detoxified for cells to survive

Anaerobic organisms lack the means to detoxify O2- which is why they can’t survive in O2 well

Question 10

How does Iron affect bacteria

Answer 10

it is required for enzyme action as it serves as a cofactor

Question 11

What type of iron do bacteria need

Answer 11

the insoluble form

Question 12

How does bacteria import Iron

Answer 12

Bacteria produce siderophores, which bind to iron ions and make it possible to import it

Question 13

What type of pH do most organisms prefer

Answer 13

Neutral conditions

Question 14

What type of acidity do bacteria tend to die in

Answer 14

Bacteria tend to die in acidic conditions (pH <6)

Question 15

Why is water important in bacteria

Answer 15

Bacteria requires soluble nutrients for diffusion into the cell so need to be in watter

Question 16

Bacteria with defective _____ can ____ in very weak solutions

Answer 16

Cell walls

Burst

Question 17

Bacteria multiply by _____

Answer 17

Binary fission

Question 18

What is binary fission

Answer 18

a single cell separates to from two new cells of equal size

Question 19

What is the rate of bacterial growth limited by

Answer 19

The availability of nutrients

Temperature

Ability to remove toxic products

Question 20

The time required to divide is called the _____ for most organisms, it is measured in _____

Answer 20

generation time

minutes

Question 21

How long does it typically take bacterial colonies to grow

Answer 21

120 mins/2 hours

Question 22

What are the phases of microbial populations

Answer 22

Lag phase

Log phase

Stationary phase

Death phase

Question 23

What happens in the lag phase

Answer 23

Adaptation to environment, active synthesis of enzymes and other constituents

Question 24

What happens in the log phase

Answer 24

Rapid production, antibiotics are most active

Question 25

How created the phases of growth of microbial populations

Answer 25

T. Robert Malthus

Question 26

What happens in the stationary phase

Answer 26

Rate of reproduction equals rate of cell death Nutrients are depleted Toxic metabolites accumulate

Question 27

What happens in the death phase

Answer 27

death rate exceeds reproduction

Question 28

What is listeria monocytogenes

Answer 28

gets into your food can be bad if you have a weak immune system

Question 29

Listeria monocytogenes is _____ with regard of oxygen, it is a gram ____ with a ____ shape, it grows best in pH range ______

Answer 29

aerobic Positive Rod 4.6-9.2

Question 30

What is active transport

Answer 30

enzymes move substrate into the cell, requiring ATP high concentration inside cell, low concentration outside cell

Question 31

In active transport, by pumping from ____ to _____ the cell organisms can become _____ to _____

Answer 31

Inside Outside resistant antibiotics

Question 32

What is group translocation

Answer 32

enzymes modify a substance as it comes into the cell, energy is needed diffusion of altered substrate is reduced

Question 33

What is facilitated diffusion

Answer 33

Enzymes aid diffusion but no energy required (passive transport) Concentration inside does not exceed exterior concentration

Question 34

What is anabolism

Answer 34

building organic molecules using small molecules + energy

Question 35

What is catabolism

Answer 35

Breakdown of chemical nutrients with release of energy

Question 36

ATP to ADP is what type of reaction

Answer 36

catabolic

Question 37

In glycolysis, glucose is _____ to ____ this process is a ____ reaction

Answer 37

broken down pyruvic acid catabolic

Question 38

What is pyruvate degraded to in Kerbs cycle

Answer 38

to CO2 and H2O and more energy

Question 39

The term used for an organism that requires complex organic molecules to enable it to grow in culture is

Answer 39

fastidious

Question 40

Iron is required for bacterial growth. How do bacteria obtain iron ions?

Answer 40

production of siderophores that are taken up after binding iron ions

Question 41

production of siderophores that are taken up after binding iron ions

Answer 41

fermentation

Question 42

The number of bacteria in urine is used to determine its clinical significance. You find a sample that was not refrigerated after taking and has been out for 6 hours. Which phase of growth would prevent the interpretation of the clinical significance of this sample?

Answer 42

Log

Question 43

what is the energy yield of glycolysis and does it need O2 and where does it happen

Answer 43

Glucose --> pyruvate 2 ATP and 2 NADH yes (anaerobic) Cytoplasm

Question 44

What is the energy yield of pyruvate oxidation and does it need O2 and where does it happen

Answer 44

pyruvate --> acetyl-CoA + CO2 Energy yield = 2 NADH Needs O2 (aerobic)

Question 45

What is the energy yield of the citric acid cycle and does it need O2 and where does it happen

Answer 45

Acetyl-CoA --> 2 CO2 Energy yield = 6 NADH, 2 FADH2, 2 ATP Needs O2 (aerobic)

Question 46

What is the energy yield of the ETC

Answer 46

NADH + FADH2 --> H2O Energy yield = 26-28 ATP