MCB 100 FULL Exam 1 (UIUC)

key distinction of microorganisms from other organisms

microorganisms do not form differentiated tissues

1 mm = ? microns

1000

1 m = ? mm

1000

1 micron = ? nm

1000

"little things" small to large

atoms ==> small molecules (amino acids, nucleotides, sugars) ==> biological macromolecules (proteins, nucleic acids, polysaccharides, lipids) ==> subcellular structures (viruses, ribosomes, microtubules) ==> Rickettsia, Chlamydia, Mycoplasma, and Nanobacteria ==> most bacteria and archaea ==> yeasts and flagellated protozoa ==> typical plant and animal cells, amoebae ==> ciliated protozoa ==> zooplankton (small multicellular animals)

subcellular aggregates of molecules

viruses, viroids, prions

traits of all living cells

1. Able to grow and reproduce (can convert nonliving nutrients into living cytoplasm)

2. Genetic material is DNA

3. Metabolism

4. Able to make or acquire ATP

5. Able to synthesize proteins

6. Bound by an active cell membrane

function of ribosomes

read mRNA and synthesize proteins

traits of viruses

1. Not cellular organisms

2. Consist of some genetic material, either DNA or RNA, surrounded by a coat of protein (capsid)

3. Some animal viruses have a membrane-like envelope of lipids and proteins, but many viruses lack this feature

4. Lack ribosomes and tRNAs -- cannot synthesize proteins on their own

5. Contain few or no enzymes -- lack metabolic pathways

6. Lack ATP -- no means of generating ATP

7. Obligate intracellular parasites -- must be inside host cell to have life-like functions

sizes of viruses and bacteria small - large

hemoglobin ==> Poliomyelitis ==> Adenovirus ==> HIV ==> Poxvirus ==> Rickettsia ==> Streptococcus ==> E. coli

have cell wall

1. Most bacteria

2. Archaea

3. Plants

4. Fungi

5. Algae

lack cell wall

1. Mycoplasma

2. Animals

3. Protozoa

cell membrane

Lipid bilayer with embedded proteins that acts as the diffusion barrier around the cell. Semipermeable.

cell wall

Net-like bag of polysaccharides that surrounds the cell and causes it to maintain a specific shape. Protects the cell from osmotic lysis but is not a barrier to the diffusion of small molecules.

prokaryotes

no nuclear membrane

bacteria

archaea

eukaryotes

have nuclear membrane

protozoa

fungi

algae

eukaryote ribosome size

80S

prokaryote ribosome size

70S

structures not found in prokaryotes

nuclear membrane, endoplasmic reticulum, mitochondria, chloroplasts, membrane-bound organelles, cytoskeleton, phagolysosomes, snRNPs

chromosome number and shape - eukaryotes

plural

linear

chromosome number and shape - prokaryotes

single

circular

size - eukaryotes

mostly 4-20mm

size - prokaryotes

mostly 0.5-3mm

fungi

Eukaryotic

Cell wall - chitin

Not photosynthetic

Nutrient molecules absorbed by osmosis

Both sexual and asexual reproduction

Most have mitochondria

Most prefer aerobic conditions

protozoa

Eukaryotic

No cell wall

Not photosynthetic

Some absorb nutrient molecules by osmosis, others engulf food particles by phagocytosis

Both sexual and asexual reproduction

Most have mitochondria

Most prefer aerobic conditions

algae

Eukaryotic

Most have cell walls - cellulose

Photosynthetic

Both sexual and asexual reproduction

Most have mitochondria

Most prefer aerobic conditions

Produce oxygen and fix carbon dioxide

bactera

Prokaryotic

Most have cell walls - peptidoglycan

Some are photosynthetic, most are not

Some can fix nitrogen

Wide variety of metabolic lifestyles

Lack true sexual reproduction

Many excrete enzymes to digest complex molecules

Some cause human disease

archaea

Prokaryotic

Cell walls - protein or pseudopeptidoglycan

Wide variety of metabolic lifestyles

Some produce methane

Some are extremophiles (hyperthermophiles)

Lack true sexual reproduction

Do not excrete enzymes to digest complex molecules

Do not cause human disease

RNA polymerase is similar to eukaryotic enzymes

viruses

Not cellular

Smaller than the smallest known cells

Lack an active cell membrane

Lack ribosomes, etc. for protein synthesis

Lack ATP generating metabolism

Must be inside a host cell to reproduce

Genetic material can be DNA or RNA, ss or ds

viroids

Infections particles seen in plants, similar to RNA viruses except they lack a capsid

prions

Infections particles

Lack nucleic acid

Altered forms of normal proteins that appear to be able to convert normal proteins to an abnormal shape upon contact

Abnormal form of protein is associated with disease

microbes are found...

wherever there is liquid water, an energy source, and carbon

microbes are the basis of...

food chains

microbes are essential for...

elemental recycling in the environment

4 questions drove the development of microbiology

1. Can living organisms arise by spontaneous generation?

2. What causes fermentation?

3. What causes disease?

4. How can we prevent and treat infectious diseases?

scientific method

1. Observations lead to the formation of a question

2. Create a hypothesis - a potential answer to the question

3. Design and conduct experiments to test the hypothesis

4. Based on the results of the experiments, the hypothesis is rejected, modified, or accepted

Aristotle

350 BC

living creatures can arise by sexual reproduction, asexual reproduction, and spontaneous generation from non-living matter

Girolamo Fracostoro

1546

Germ theory of disease

Robert Hooke

1665

Describes tissue structure of cork, uses term "cell"

Francesco Redi

1668

Complex animals don't arise due to spontaneous generation - maggots don't appear spontaneously in meat

Antony Van Leeuwenhoek

1676

Observes bacteria and protozoans using a simple microscope of his own construction

Revived spontaneous regeneration debate

Lazzaro Spallanzani

1776

Repeated Needham's experiments, but avoided contamination of his broths by airborne bacteria.

Sealed flasks also kept out oxygen.

Edward Jenner

1789

Smallpox vaccine

Thoedor Schwann and Matthias Schleiden

1839

All living things are composed of cells

Ignaz Semmelweis

1847

Institutes handwashing - procedure saved lives, but wasn't popular with medical students

Florence Nightingale

1855

Antiseptic nursing practices

Rudolf Virchow

1858

All cells originate from preexisting cells

Lois Pasteur

1861 - goose-necked flasks - bacteria do not appear in sterilized media

Yeast turn grape juice into wine, but bacteria cause wine spoilage

Pasteurization

Starter cultures

Anthrax vaccine for sheep

Rabies vaccine

Joseph Lister

1867

Antiseptic surgery

Robert Koch

1876 - Shows anthrax caused by a specific microorganism

Father of microbiology laboratory procedures

Discovered cause of tuberculosis, cholera

Invented streak plate technique to get a pure culture

Koch's postulates

Introduced use of agar and Petri dishes

Took first photomicrograph

Koch's postulates

Set of rules used to prove that a certain microorganism causes a disease

1) Isolate an atypical microorganism from patients with the disease and be able to identify the microorganism

2) Obtain a pure culture of the suspicious microorganism

3) Inoculate healthy susceptible hosts with the microorganism of interest and observe the appearance of the disease in question in the inoculated animals but not in uninoculated animals in the control group

4) Re-isolate the suspicious microorganism from the experimental hosts that get the disease of interest and repeat the process

Behring and Kitasato

1890

Discover antibodies in serum from immunized animals that neutralize toxins of diphtheria and tetanus

Eduard Buchner

First studies of enzymes

Showed that cell free extracts of yeast could convert sugar to alcohol

Ivanowski

1892

Discovered tobacco mosaic virus

Ross and Grassi

1898

Demonstrate that malaria is transmitted by mosquitoes

Beijerinck

1899

Shows that tobacco mosaic virus reproduces in living cells

Ehrlich

1908

Develops compound used to treat syphilis

Francis Rouse

1910

Discovers viruses that can cause cancer

Alexander Fleming

1929

Discovers penicillin

Frederick Griffith

1929

Discovers genetic transformation in Streptococcus pneumonia

Avery, MacLeod, and McCarty

1944

Show that DNA is the genetic material

Berg, Boyer, and Cohen

1973

Develop techniques to produce recombinant DNA in vitro

Carl Woese

1977

Used molecular analysis to discover the difference between bacteria and archaea

4 eras in history of microbiology - traditional practices/ancient times

Making products using microorganisms without any knowledge of the existence of microorganisms

4 eras in the history of microbiology - the "golden age"

Late 1800s

Pasteur, Buchner, Koch, Lister, Ehrlich, and others discover role of microorganisms in fermentation and infectious diseases and develop techniques to control microorganisms.

4 eras in the history of microbiology - the "classical age"

Early 1900s

Fleming, Florey, Waksman, Salk, Weizmann and others develop methods to produce antibiotics, enzymes, vaccines, and organic solvents using natural strains of microorganisms

4 eras in the history of microbiology - the biotechnology era

Late 1900s to present

Recombinant DNA technology is used to create new strains of microorganisms that can produce desirable products

Properties of living matter

1. Contains carbon

2. The atoms in an organic molecules are held together by covalent bonds

3. Living organisms are mostly made of about 20 different elements

4. 6 elements make up most of the mass of organic compounds (C, H, O, N, P, S) & can form covalent bonds

5. The proteins, nucleic acids, lipids, and carbs that form living matter are large, complicated molecules (macromolecules)

6. There are several thousand different types of proteins found in a typical cell

7. Biological macromolecules stick to each other in very specific ways due to noncovalent attractions. This produces a higher level of order. Enzyme subunits can stick to each other and work together. Regulatory proteins can bind to specific DNA sequences. Ribosomal subunits stick together.

8. A cell is an organized system

mixture

A substance (or sample) that can be broken down into different parts by physical manipulations that don't necessarily involve chemical changes

compound

A pure substance that can be broken down into different parts only by chemical reactions

element

A pure substance that can't be broken down into different parts by chemical reactions

molecule

The smallest particle possible for a compound

atom

The smallest particle possible for an element

ionic bonds

Formed when 1+ electrons are transferred from one atom to another resulting in a charge imbalance in both atoms.

Ions with opposite charges are attracted to each other but don't necessarily remain in physical contact with each other.

cation

atom that loses the electron in an ionic bond, becoming a positively charged ion

anion

atom that gains the electron in an ionic bond, becoming a negatively charged ion

oxidation-reduction reaction

Involves a transfer of electrons from one atom to another atom.

oxidation

Loss of electrons

reducation

Gain of electrons

reducing agent

supplies the electron that reduces the charge of the other atom

oxidizing agent

accepts the electron from the other atom, causing the other atom to become positively charged

covalent bonds

2 atoms share a pair of electrons.

Atoms must touch each other.

double covalent bond

2 atoms share 2 pairs of electrons

triple covalent bond

2 atoms share 3 pairs of electrons

quadruple covalent bond

not possible

compounds made of atoms held together by ionic bonds tend to be...

simple

compounds made of atoms that are held together by covalent bonds can be...

very large and complex

bacterial cellular components

Proteins (polymers of AAs)

Nucleic acids (RNA, DNA)

Phospholipids (diglycerides)

Polysaccharides (carbs)

proteins

Polymers of amino acids - long unbranching chains of amino acids

Large globular molecules

Cytoplasmic enzymes

Cell membrane components

Flagella and fimbrae

Genetic regulatory factors

Some found in the cytoplasm and others are embedded in the cell membrane

nucleic acids

Polymers of nucleotides - no branching

RNA and DNA

Genetic material

Ribosome components

Enzyme cofactors

phospholipids

Diglycerides

Cell membrane components

polysaccharides

Chains of sugars and modified sugars (these often have branching chains)

Carbohydrates

Cell wall components

Capsular materials

Food storage molecules (starch)

Can be slimy or sticky substances

polymer

A large molecule that is made of many smaller molecules joined together by covalent bonds to make a long chain that may or may not have branches

lipids

Large amphipathic molecules that form the matrix of cell membranes

Part of the molecule is attracted to water while part of the molecule is repelled by water

starch

Polymer of glucose subunits

hydrocarbon

Composed of just carbon and hydrogen

saturated hydrocarbon

all C-C bonds are single bonds

methane

CH4

Alkane

1 carbon

ethane

C2H6

Alkane

2 carbons

propane

C3H8

Alkane

3 carbons