BIOL 2051 FINAL EXAM 1_UPDATED,100% CORRECT

BIOL 2051 FINAL EXAM 1_UPDATED
EXAM 1
Introduction to Microbiology
1 Define microbiology?
Study of cells or organisms to small to be seen from the naked eye
2 Where do you find microorganisms?
everywhere
3 How many microorganisms are estimated to be on Earth?
2.5 x 10^30
4 How long have microorganisms been on Earth?
 4 Billions of years
5 Are the majority of microorganisms beneficial or harmful?
 beneficial
6 Do good or bad microorganisms get the most publicity? Why?
 Good, they have many impacts on our lives
7 How do microorganisms impact our lives through the following:
A Disease
i Cure, prevention, and treatment of diseases
B Agriculture
i Symbiotic relationships converting atm nitrogen to fixed nitrogen
C Food
i Cheeses, yogurt, dairies, food preservation
D Energy
i Biofuels, methane, ethanol
E Bioremediation
i Help clean toxic spills, clean pollution
F Biotechnology
i pharmaceuticals

,BIOL 2051 FINAL EXAM 1_UPDATED
8 What are microorganisms made of?
 Cytoplasm, cell membrane, ribosomes, DNA
Structure & Function
1 Name 6 characteristics of living cells.
 Metabolism  Differentiation
 Reproduction  Movement
 Communication  evolution
2 Who was the first to use a microscope to see microorganisms? What did he
see? What type of microscopy did he use?
Robert hooke 1665 mold, light
3 Who was the first to use a microscope to see bacteria? How do we know he saw
bacteria?
Antoni van leuwerisk, pepper water infusions
4 What type of microscopy did he use?
 electron
5 What are the four types of light microscopy?
 Brightfield  Darkfield
 Phase contrast  fluorescense
6 What must be done to a microorganism to be able to see it with brightfield light
microscopy?
 Must cut the cell, stain them as well. This kills the cells
7 Which types of light microscopy allow you to view a live sample?
 Phase contrast and darkfield
8 What is the maximum resolution of a compound light microscope? Describe
what that value means in practical terms when viewing a specimen.
 .2 this means any two organisms next to each other wont be seen as next
to each other . wont be seen as resolved and distinct

,BIOL 2051 FINAL EXAM 1_UPDATED
9 What are the two types of electron microscopy? When would you use one type
instead of the other?
 Transmission—internal  Scanning –outside features
details
10 What is the maximum resolution of an electron microscope?
 .2-4 nm
11 What is the smallest microbial cell size discovered thus far? Would this cell have
a high or low surface area-to-volume ratio compared to an average eukaryotic
cell?
 .2, high surface area to volume
12 What is the significance of a cell having a high surface area-to-volume ratio?
 Good for nutrient and waste exchange
13 Discuss the problems a cell might have it were less than 0.2microns.
 Wouldn’t have all cell components to live
14 Compare and contrast a prokaryotic microbial cell and eukaryotic microbial cell.
 Prok—smaller, no cell organelles, circular DNA, transcription and
translation performed together. Have hopanoids in membrane
 Euk—larger, transcription in nucleus and translation in cytoplasm.
Organelles, have sterols in membrane
15 What microorganisms have a phospholipid bilayer form their cytoplasmic
membrane?
 Prok and euk—have ester linkages with fatty acids
16 What microorganisms have a lipid monolayer form their cytoplasmic membrane?
 Archaea—have ether linkages
17 Contrast the phospholipid bilayer with the lipid monolayer? What molecules
make up each? What are the different linkages characteristic of each?
 Bilayer—polysaccharides, ester linkages

, BIOL 2051 FINAL EXAM 1_UPDATED
 Monolayer—ether linkages b/t glycerol and hydrophobic side chains
18 What advantage would microorganisms with a lipid monolayer have over those
with a lipid bilayer?
 Harder to break single attached molecule than two separate membranes,
heat resistant as well.
19 What are the functions of the cytoplasmic membrane?
 Permeablility, energy conservation, transport.
 Specific transport mechanisms for nutrients going against concentration
gradient
20 Where is the cell wall located relative to the cytoplasmic membrane?
 Outside of membrane
21 What Bacteria lack a cell wall?
 Mycoplasma and chlamydia
22 What are most Bacteria cell walls made of?
 peptidoglycan
23 The amount of peptidoglycan in the cell walls of Bacteria distinguishes what
types of Bacteria?
 Gram pos--thicker
 Gram neg—multilayer more complex
24 Describe the peptidoglycan structure.
2 sugars: G and M bonded by a beta-1,4 bond. 4 amino acid crosslink
Repeating N-Acetylglucosamine and N-Acetylmuramic acid subunits with peptide
crosslinks
25 The glycosidic bond between the two N-acetyl-glucose sugars in peptidoglycan
can be cleaved by what enzyme? What is the significance of using that enzyme
to cleave that bond?