BIO-215: Quiz 1

Exergonic

Reactions in which energy is released. Energy is EXITING. Reactants have more energy than the products. Catabolic - hydrolysis Reaction proceeds with a net release of free energy. Ex: respiration

What experiment disproved the theory of spontaneous generation?

Redi's rotting meat experiment. Demonstrated that worms found on the rotting meat came from eggs of flies landing on meat. Experiment: placing rotting meat in jars. One jar open, another covered with gauze, and a third sealed with a lid. Result: Worms only appeared on jar that was left open. (No eggs = no worms) Conclusion: living organisms give rise to life.

Pyruvate metabolism - 2 major routes

Respiration or fermentation

Bacillus

Rod-shaped bacterium

Describe the different shapes and arrangements of prokaryotic cells and give specific examples of each.

See below.

Electron Transport Chain (ETC)

Series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

Vibrio

Short, curved rod

Why is lipopolysaccharide medically significant?

Signals immune system of invasion by Gram-negative bacteria

Viroid

Simpler than viruses, consisting of only a single, short piece of RNA. Causes several plant diseases.

Archaea

Single-celled prokaryotes. Similar shapes, sizes, and appearances to bacteria. Multiply by binary fission, move primarily by means of flagella, and have rigid cell walls.

Coccus

Spherical; ex: Aerococcus urinae (causes urinary tract infections and urosepsis)

The Theory of Spontaneous Generation

States that "living organisms could spontaneously arise from non-living material." AKA - Abiogenesis

Acid fast stain

The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body substance is infected with the bacteria that causes tuberculosis (TB) and other illnesses.Sep 11, 2019

Reduction

The addition of electrons from another substance. (More electronegative) Ex:Cl -> Cl-

Describe a typical bacterial chromosome

The bacterial chromosome is one long, single molecule of double stranded, helical, supercoiled DNA. In most bacteria, the two ends of the double-stranded DNA covalently bond together to form both a physical and genetic circle

Kinetic energy

The energy of motion.

Intermediates

The further broken down pieces of pyruvate.

Oxidation

The loss of electrons from one substance to another. (Less electronegative) Ex: Na -> Na+

Proton motive force

The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis. (ETC)

Oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration. Generates the most ATP.

Biogenesis

The production of living things from other living things.

Metabolism

The totality of an organism's chemical reactions. It involves both building up (anabolism) and breaking down (catabolism) of molecules.

Bioremediation

Using microorganisms to hasten decay of pollutants. Degrade PCBs, DDT, trichloroethylene, and others. Help clean up oil spills.

Coccobacillus

Very short rod

Examples of Extrachromosomal DNA

Viral DNA are an example of extrachromosomal DNA. Understanding viral genomes is very important for understanding the evolution and mutation of the virus. Some viruses, such as HIV and oncogenetic viruses, incorporate their own DNA into the genome of the host cell.

Why are microorganisms a useful model organism for study?

We could not survive without them. Ex: nitrogen fixation, oxygen production, degradation of materials, food production, biodegradation, biotechnology, genetic engineering.

Explain how Gram-positive bacteria might appear as Gram-negative

When over-decolourized by either prolonged exposure to decolourizer or using acetone alone. When cell wall gets damaged by exposure to lysozyme or cell wall acting antibiotics such as Penicillin.

Bacteria - model organism to study

Wonderful model organism because of: -Metabolism, genetics same as higher life-forms All cells composed of same elements, synthesize structures in a similar way, replicate DNA, similar metabolic pathways.

Helminths

Worms that live at the expense of a host. Cause diseases.

Differential staining

using specific stains to distinguish different types of cell.

Gram's stain - procedure.

1. Crystal violet (primary stain) 2. Iodine (mordant) 3. Alcohol (decolorized) 4. Safranin (counterstain)

What are the 3 Domains and the major characteristics of each?

Bacteria, archaea, and eukarya. Bacteria and archaea are prokaryotes; eukarya are eukaryotes

Catabolism

Breaking down. Exergonic Ex: respiration - cells break down glucose to extract its energy.

Anabolism

Building up. Endergonic Ex: photosynthesis - plants take light energy and convert it into food.

In cellular respiration, what gets oxidized and what gets reduced?

C6H12O6 + 6O2 -> 6CO2 + 6H2O Glucose is oxidized to CO2 (loss of electrons/energy). Oxygen is reduced to H2O (gain of electrons/energy).

The major criterion used in placing bacteria into 2 different groups is based on differences in which cell structure?

Cell wall

ATP

Cell's energy shuttle. P-P-P, the third P, or terminal phosphate bond will be broken via hydrolysis to release energy. ATP derives endergonic reactions by phosphorylation (gain of phosphate group); ADP -> ATP

Streptococcus

Chain

Other names for glycolysis and Krebs cycle

Citric acid cycle: Krebs cycle. Glycolysis: The cellular degradation of the simple sugar glucose to yield pyruvic acid and ATP as an energy source.

Gram-Negative Cell Wall

Color of Gram-stain: pink Representative Genera: Escherichia, Neisseria, Pseudomonas Peptidoglycan: Thin layer Teichoic acids: Absent Outer membrane: Present Lipopolysaccharide (endotoxin): Present Porin proteins: Present; allow molecules to pass through outer membrane Sensitivity to penicillin: generally less susceptible Sensitivity to lysozyme: No

Gram-Positive Cell Wall

Color of Gram-stain: purple Representative Genera: Bacillus, Staphylococcus, Streptococcus Peptidoglycan: Thick layer Teichoic acids: Present Outer membrane:Absent Lipopolysaccharide (endotoxin): Absent Porin proteins: Absent (unnecessary because there is no outer membrane) Sensitivity to penicillin: Generally more susceptible Sensitivity to lysozyme: Yes

Viruses

Consist of nucleic package with a protein coat. To multiply, they infect living cells (hosts) and then use the machinery and nutrients of the hosts to replicate. All forms of life can be affected by these. DNA and RNA

Sarcina

Cubical packets

Rod

Cylindrical; ex: Bacillus anthracis (B. anthracis), or anthrax.

Slime layer

Diffuse, irregular

Terms used to describe bacterial morphology/groupings

Diplococcus, Streptococcus, Sarcina, Staphylococcus

Endospores

Discovered by Ferdinand Cohn. Heat-resistant form of bacteria. Were present in the hay infusions used in experiments on Spontaneous Generation.

Capsule

Distinct, gelatinous The bacterial capsule is a large structure composed of a polysaccharide layer that is outside the cell envelope. Some allow bacteria to invade host immune system

Fungi

Diverse group of eukaryotes, ranging from single-celled yeasts that can reproduce by budding to multicellular filamentous molds (hyphae).

Protozoa

Diverse group of microscopic single-celled eukaryotes that live in both aquatic and terrestrial environments. Very complex and much larger than prokaryotes. Do not have a rigid cell wall; most are motile and ingest organic material as food sources.

Algae

Diverse group of photosynthetic eukaryotes. Some single-celled, others multicellular, such as such as seaweed. Contain chloroplasts (photosynthesis).

Endospore stain

Endospores staining is the type of staining to recognize the presence spore in bacterial vegetative cells. The bacterial endospores need a staining which can penetrate wall thickness of spore bacteria. A method of endospores staining is Schaeffer Fulton method that used Malachite Green.

Endergonic

Energy is consumed or absorbed. Energy is ENTERING. The products have more energy than the reactants. Consume energy to build up polymers from monomers. Ex: dehydration synthesis These reactions store chemical energy Chemical reactions that break down large. molecules that follow catabolic pathways and are called catabolism. Ex: photosynthesis

Potential energy

Energy matter possesses because of its location or structure. (Stored energy)

Extrachromosomal DNA

Extrachromosomal DNA (abbreviated ecDNA) is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell.

Plasmids

Extrachromosomal, circular, supercoiled DNA. Usually much smaller; few to several hundred genes. May share with other bacteria; antibiotic resistance can spread this way. A genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan.

Movement in bacteria

Flagella and pili

Cell wall

Found only in bacteria Determines shape of bacteria Prevents the bacteria from bursting Made from peptidoglycan Is targeted by antimicrobials

Scientists involved in investigating the idea of spontaneous generation.

Francesco Redi, Louis Pasteur, and John Tyndall

Eukarya

Fungi, algae, protozoa, and helminths. Protists - algae and protozoa

Gram-positive and Gram-negative stain coloration:

Gram+ - blue Gram- - red

Staphylococcus

Grape-like clusters

Products for ETC

H2O, 38 ATP

The structures present in the hay infusions

Heat-resist microbes (endospores)

Advantage of the smaller size of prokaryotes

High surface area relative to low cell volume and more rapid growth rates.

"Animalcule" definition and was coined by...

Microscopic animals. Coined by Antony van Leeuwenhoek.

Bacteria

Most have specific shapes, commonly cylindrical, spherical, or spiral. Multiply via binary fission. (Once cell enlarges and then divides, forming two cells each equivalent to the original)

Bacteria that lack a cell wall? Biofilm

Mycoplasma species have extremely variable shape-pleomorphic

Electron carriers example

NADH, FADH2

Writing scientific name

Names of the domains are italicized with the first letter capitalized. Genus - first name, letter is always capitalized. Species - second name, not capitalized.

The system by which organisms are named is

Nomenclature

Acellular Infectious Agents

Not composed of cells, they cannot reproduce independently, and are considered non-living. Not microorganisms.

Major groups of the microbial world

Organisms (living) and Infectious agents (non-living) Know how they branch out.

Diplococcus

Pairs

Explain why penicillin kills only actively multiplying cells, whereas lysozyme kills calls in any stage of growth.

Penicillin will kill only cells that are actively synthesizing peptidoglycan (i.e. cells that are growing) because it interferes with peptidoglycan synthesis. Lysozyme breaks the bonds that join the subunits, thereby weakening the existing structure.

Molecules (macro) found in the cell wall of all bacteria

Peptidoglycan

Pili

Pili (sing, pilus) are shorter than flagella. Types that allow surface attachment termed fimbriae. Twitching motility, gliding motility involve pili. Sex pilus used to join bacteria for DNA transfer.

Fermentation

Process by which cells release energy in the absence of oxygen.

The cell types that lack a membrane-bound nucleus

Prokaryotes

Gel-like layer outside cell wall that...

Protects or allows attachment to surface. Ex: capsule or slime layer Most composed of glycocalyx (sugar shell) although some are polypeptides. Once attached, cells can grow as biofilm. Ex: dental plaque

Unique structure seen in archaea and not prokaryotes

Proteoglycan in archaea cell wall.

Pleomorphic

Bacteria that characteristically vary in their shape.

Simple staining

the use of a single stain to color a bacterial cell

Products for Glycolysis

2 ATP, 2 pyruvates, 2 NADH

Products for Krebs Cycle/Tricarboxylic Acid

2 CO2, 3 NADH, 1 FADH2, 1 ATP, various intermediates

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

Peptidoglycan

A protein-carbohydrate compound that makes the cell walls of bacteria rigid.

Terminal electron acceptors - all

Aerobic - oxygen Anaerobic - nitrate Fermentation - pyruvate

Anaerobic vs. aerobic respiration

Anaerobic - no oxygen, less ATP, fermentation Aerobic - oxygen, more ATP, respiration

Describe a bacterial ribosome

Are used for protein synthesis. 30S and 50S are combined to form ribosome 70S.

Prions

Infectious proteins that cause diseases called spongiform encephalopathies(reflects the sponge-like appearance of the brain tissue). Misfolded version meets the normal cellular protein, it forces the normal protein to also misfold. Misfolded versions bind together to form thread-like structures called fibrils. They are not able to function and eventually die, forming spaces in the brain that lead to the sponge-like appearance.

Flagella

Involved in motility Bacteria sense chemicals and move accordingly. Nutrients may attract, toxins may repel. Movement is series of runs and tumbles.

Penicillin is effective against G+ or G-?

It is effective against G+ and ineffective against G-.

Central metabolic pathway that generates most of the reducing power

Krebs Cycle

Endotoxin

LPS (Lipopolysaccharide) is called this. A toxin that is present inside a bacterial cell and is released when the cell disintegrates. Found in the cell wall of Gram-negative bacteria, which can induce inflammation and fever as an immune response in higher organisms.

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Spirochete

Long spiral-shaped cell with a flexible cell wall and unique mechanism of motility.

Cell wall of prokaryotes

rigid structure outside the plasma membrane, made of peptidoglycan.