Study Guide Week 3

chapters 1,3,4,5 and 6

Antoni Van Leeuwenhoek and his discoveries and his first observations, also the limitations

Used a simple microscope to be the first to see "animalcules" (microbes).

He never shared his lens-making secrets, and his tech couldn't see viruses. He observed bacteria, protozoa, and sperm cells, greatly contributing to microbiology.

Characteristics of fungi

Eukaryotic cells have cell walls (chitin) and obtain food from other organisms. They reproduce by spores and can be unicellular or multicellular. Examples: molds, yeast

Characteristics of Protozoa

Single-celled eukaryotes, similar to animals in nutritional needs and structure; most are capable of locomotion. Live in water or as parasites

What is bioremediation?

Using microbes to detoxify polluted environments. Example: bacteria breaking down oil spills

Pasteur’s experiments on Spontaneous Generation (proving/ disproving)

Used swan-necked flasks to disprove spontaneous generation; proved microbes in the air contaminate broth, but air itself doesn't "create" life.

Synthesis of insulin using E. coli (with reference to Recombinant technology)

Recombinant DNA technology inserts the human insulin gene into E. coli to mass-produce the hormone. Bacteria produce insulin → used for diabetes

Cell structures and biofilms

Biofilms = communities of microbes stuck to surfaces

Protected by slimy layer → harder to kill

What are the processes of life for free living organisms? With applications

Growth, Reproduction, Responsiveness, and Metabolism. Example: bacteria dividing in your body.

Components of flagella

Filament, Hook, and Basal Body (the motor).

Function of eukaryotic plasma membrane

 Controls entry/exit (semi-permeable) and contains sterols for stability. Maintains homeostasis

Function of membranous organelles

Nucleus → DNA

Mitochondria → ATP

ER/Golgi → protein processing

Principle of Gram staining

Based on cell wall differences

Gram + = purple (thick peptidoglycan)

Gram – = pink (thin layer + outer membrane)

Significance of pili/fimbriae, how is it different from the flagella

Fimbriae: Short, hair-like; for adhesion and biofilms.

Pili: Longer than fimbriae; used for DNA transfer (conjugation).

Flagella: Long, for motility.

Prokaryotes

Bacteria and Archaea

Eukaryotes

Fungi

Protozoa

Algae

Small multicellular animals

Discoveries by Semmelweis

Handwashing (childbed fever)

Discoveries by Lister

Antiseptic surgery (phenol)

Discoveries by Nightingale

Hygiene/sanitation in nursing

Discoveries by Jenner

Smallpox vaccine (immunology)

Learn conversions from millimeter to micrometer and nanometer

1 mm = 1000 µm

1 µm = 1000 nm

Size of a virus metric equivalent

nanometers (nm)

Dyes used in acid-fast staining

Carbol fuchsin, Acid-alcohol and Methylene blue

Primary stain Carbol fuchsin

Penetrates waxy cell wall (with heat), All cells turn red

Acid-alcohol

Removes stain from non-acid-fast cells, only acid-fast stay red

Methylene blue

Stains non-acid-fast cells, non-acid-fast turn blue/green

Characteristics of classifying micro-organisms

Shape, structure, metabolism, genetics

Calculate magnification of an object

Total Magnification=Eyepiece (ocular)×Objective lens

Functions and parts of a microscope: “Magnification”

eyepiece + objectives

Functions and parts of a microscope: “Light control”

condenser + diaphragm

Functions and parts of a microscope: “Focusing”

coarse & fine knobs

Functions and parts of a microscope: “Support”

arm + base + stage

Synthesis of  ATP molecules from glucose in aerobic respiration? “Prokaryotic aerobic respiration”

(oxygen is present) 36–38 ATP per glucose

Synthesis of  ATP molecules from glucose in aerobic respiration? “Prokaryotic Anaerobic respiration”

(no oxygen, but still uses ETC), 2-36 ATP per glucose

Fermentation

(no oxygen), (no ETC), 2 ATP

Carbohydrate Fermentation

bacteria ferment different sugars and produce end products, these end products bring about a change in the medium

What are exergonic reactions?

 releases energy

What are endergonic reactions?

equire more energy than they release

Enzymes are biological catalysts that

speed up chemical reactions

Lower activation energy

Are specific to their substrates

Are not consumed in the reaction

All the 6 categories of enzymes

Hydrolases

Isomerases

Ligases or polymerases

Lyases

Oxidoreductases

Transferases

Hydrolases Enzymes

Break bonds with water

Isomerases Enzymes

Rearrange structure

Ligases or polymerases Enzymes

Join molecules using ATP

Lyases Enzymes

Break/form double bonds

Oxidoreductases Enzymes

Redox (electron transfer)

Transferases Enzymes

Transfer functional groups

 Structure and function of enzyme

Enzymes are proteins with a specific active site that bind substrates, catalyze reactions, release products, and return to their original shape so they can be reused.

Electron Transport Chain

is the final stage of cellular respiration where most ATP is produced

Alcoholic fermentation

ethanol + CO₂, microbe: (Saccharomyces)

Acidic fermentation

Lactic acid, microbes: (Lactobacillus), (Aspergillus), (Streptococcus)

Examples of anabolic reactions

 Builds molecules

 Examples of catabolic reactions

Breaks down molecules

Review of chemical and energy requirements

What are microbes with different requirements of oxygen called? “Obligate aerobes”

Must have O₂

What are microbes with different requirements of oxygen called? “Obligate anaerobes”

O₂ is toxic

What are microbes with different requirements of oxygen called? “Facultative anaerobes”

With or without O₂, if oxygen is not present it can switch to fermentation

What are microbes with different requirements of oxygen called? “Aerotolerant anaerobes”

Tolerates O₂, doesn’t use

Necessary information on nitrogen requirements

Anabolism often ceases because of insufficient nitrogen

Nitrogen acquired from organic and inorganic nutrients

All cells recycle nitrogen from amino acids and nucleotides

Nitrogen fixation by certain bacteria is essential to life on Earth 

Events of binary fission

1. DNA replicates

2. Cell elongates

3. Middle wall forms

4. Cell divides into two identical cells

Review of physical requirements for microbial growth

Include temperature, pH, osmotic pressure, oxygen availability, and light, all of which influence enzyme activity and cellular processes

Figure 6.5  Four categories of microbes based on temperature ranges for growth

What are the different kinds of culture media “Defined media”

Exact chemical composition is known; Research where exact nutrients must be controlled

What are the different kinds of culture media “Complex Media”

Exact composition is unknown; General growth of many microorganisms

What are the different kinds of culture media “Selective Media”

Allows some microbes to grow, inhibits others; Isolate a specific group of bacteria

What are the different kinds of culture media “Differential Media”

Distinguishes between microbes based on biochemical reactions; Identify differences (e.g., sugar fermentation)

What are the different kinds of culture media “ Anaerobic Media”

Designed for microbes that cannot tolerate oxygen; Grow obligate anaerobes

What are the different kinds of culture media “Transport Media”

Maintains microbes during transport (does NOT promote growth); Carry specimens to the lab safely

Calculation of generation time (Imp)

g=t/n