Lecture 2 Notes (Part 2)

Question 1

What does Na do in the environment?

Answer 1

Reduces water activity

Question 2

Where can bacteria survive when they can tolerate high concentrations of salt? (2)

Answer 2

Allows them to survive temporal and spatial change of salinity

1. Ecosystems
2. Saltmarsh

Question 3

What is a major source of energy for the biosphere?

Answer 3

Light

Question 4

What does light drive?

Answer 4

Thermic processes associated to climate

Question 5

What are the 3 aspects to temperature?

Answer 5

1. Temp as a factor that affects the rate of chemical reactions catalyzed or not by enzymes
2. Temp as a key factor for the survival of organisms
3. Climate is largely driven by temp

Question 6

What are proteins sensitive to?

Answer 6

Denaturation and temps higher than their optimum range

Question 7

What happens to chemical reactions and enzyme activity as temp increases?

Answer 7

They increase too

Question 8

What is a negative aspect to too high of temp?

Answer 8

Breaking of bonds that can lead to denaturation and inactivation

Question 9

What is high temp usually associated with? (3)

Answer 9

1. Hot springs
2. Hydrothermal vents
3. Volcanoes

Question 10

At what temp can phototrophic organisms no longer grow?

Answer 10

> 37 deg C

Question 11

At what temp can only some chemolithotrophic bacteria grow?

Answer 11

> 73 deg C

Question 12

What do prokaryotes need in order to avoid inactivation of proteins? What are 2 examples?

Answer 12

Special adaptations

1. Subtle changes in hydrophobic interactions
2. Salt bridges

Question 13

What are thermophiles and hyperthermophils associated with?

Answer 13

Geothermic energy

Question 14

Mesophil

Answer 14

Is an organism that grows best in moderate temp

- 20-49 deg C

Question 15

Thermophile

Answer 15

Is an organism that thrives at relative high temp

- 41-122 deg C

Question 16

Psycrophile

Answer 16

Is an organism that is capable of growth and reproduction in cold temp
- -20-10 deg C

Question 17

How long ago did O2 appear?

Answer 17

2 billion years ago

Question 18

What did organisms do before O2 appeared?

Answer 18

Most organisms were likely chemoautotrophic or fermentation

Question 19

What allows glucose (or acetate) to produce more energy from the same mol of glucose?

Answer 19

Photosynthesis

Question 20

Decrease in energy does what for growth?

Answer 20

Decreases it

Question 21

What is population?

Answer 21

Requirement of communities of various species to recycle nutrients and create a growing environments

Question 22

What is a very common tree on the island?

Answer 22

Douglas Fir

Question 23

What can statistics do?

Answer 23

Create parameters for restrictions

Question 24

How can we study a biological population? (3)

Answer 24

1. Need to determine what constitutes an individual
2. How it will be observed
3. How it will be treated for statistical analysis
   - eg) take a swab, culture it and count the results

Question 25

Oak-Hickory populaiton

Answer 25

Non-linear relation that can be linearized by using a logarithmic scale that allows for a regression determination of the death rate

Question 26

Unlike plants and animal, what can prokaryotes not do?

Answer 26

Be counted directly

Question 27

What is the device called thats used to count cells?

Answer 27

microscope | - hemacytometer

Question 28

How do you use a hemacytometer? (4)

Answer 28

1. Use a slide with a grid and put a drop of sample on it 2. Select the field of choice 3. Calc the average of cells in the grids 4. Calc the number of cells in the sample

Question 29

What is electron microscopy measuring?

Answer 29

Wavelengths

Question 30

What are epiflourescense used to look at?

Answer 30

Stains

Question 31

What are petri dishes used for?

Answer 31

Culturing | - most common

Question 32

What is a spectrophotometer used for?

Answer 32

Counting bacteria by looking at the density of the suspension

Question 33

What is the most modern way of counting bacteria? (2)

Answer 33

1. Quantitative PCR | 2. Molecular probing

Question 34

What is a negative aspect of microscopes?

Answer 34

Cant tell whether the cells are alive or dead

Question 35

Viable count

Answer 35

Gives a quantitative idea about the presence of microorganisms - counting cells that are able to grow - eg) bacteria, yeast and mold

Question 36

Direct count

Answer 36

Counting blood/tissue cells by using a hemocytomer can be determined the concentration of a known volume - can detect between live and dead cells

Question 37

Turbidmetry

Answer 37

Is the process of measuring the loss of intensity of transmitted light due to the scattering effect of particles suspended in it

Question 38

Monod's experiment

Answer 38

Used E.coli as an experimental modle to understand bacterial population

Question 39

What was the limiting factor for growth of E.coli?

Answer 39

Glucose | - if ran out of glucose then they used lactose

Question 40

What does a plateau on the graph indicate?

Answer 40

It means that the bacteria is re-engineering and creating new proteins cause it is developing new proteins

Question 41

What does the presence of lactose induce?

Answer 41

Transcription of genes

Question 42

What are the 6 growth phases?

Answer 42

1. Lag 2. Acceleration 3. Exponential 4. Retardation 5. Stationary 6. Declining

Question 43

Lag phase

Answer 43

Growth rate null - no cell division - no DNA replication

Question 44

Acceleration phase

Answer 44

Growth rate increases

Question 45

Exponential phase

Answer 45

Growth rate is constant | - cell division

Question 46

Retardation phase

Answer 46

Growth rate decreases

Question 47

Declining phase

Answer 47

Growth rate is negative

Question 48

What phase is used to define a population in biology?

Answer 48

Exponential phase | - ideal condition for cells