Microbiology Exam 1

Prions

-Simpler and smaller than viruses

-No nucleic acid, only protein, act like infect microorganisms

Virus

-not independently living cellular organisms

-exist at the level of complexity somewhere between large molecules and cells

-composed of a small amount of hereditary material (DNA or RNA) surrounded by a protein coat and sometimes a membrane

Bacteria

-single-celled, no true nucleus

-prokaryote

-lack organelles

-bacteria were responsible for the appearance of oxygen in the atmosphere, but also produce CO2, NO, and CH3

Eukaryote

-“True nucleus”

-many are single-celled

-developed into highly complex multicellular organisms

-larger size

-a small minority compared to bacteria and archea

Microbes’ human uses and pathogens

Historical uses of microbes by humans:

1. Bread production

2. alcohol production

3. cheese production

4. treatment of wounds and lesions

5. mining precious metals

6. cleaning up human-created contamination

   1. Microbes harming Humans

      -most microorganisms that associate with humans are harmless or beneficial

      Pathogens: do cause harm, microbes that cause disease

      -2,000 different microbes cause disease

      -over ten billion infections occur across the world every year

      -infectious diseases are important causes of death worldwide

      Microbes and Disease

      -examples of emerging and remerging diseases (TB, Zika virus, hepatitis C, West Nile virus, AIDS, SARS-coV2

      -humans actions can play a role in the emergence or remergence of pathogenic microbes

Louis Pasteur

-Studied the role of microorganisms in the fermentation of beer and wine

-swan-necked flask experiments were developed to disprove spontaneous generation

—Filled flasks with broth and shaped the openings into long, swan-necked tubes

—Heated the flasks to sterilize the broth

—Flasks that were exposed to dust from the air showed microbial growth

—flasks exposed to air but not to dust showed no microbial growth

-invented pasterurization

-conducted the first studies linking human disease to infection

Robert Koch

-studied household objects, plants, and trees

-Described cellulr structures and drew sketches of “little structures” that seemed alive

-microbiology is only possible because of him

-Koch’s postulates are a series of logical steps that establish whether an organism is pathogenic and which disease it caused (showed that anthrax was caused by Bacillicus anthracis in 1875)

Antoine Van Leeuwenhoek

-manufactured simple microscopes to study fabrics

-observed “animals” in a drop of water

-observed “animacules” scraped from teeth

-constructed over 250 small microcopes that could magnify objects up to 300 times

Oliver Wendell Holmes and Ignaz Semmelweis

-Described the importance of hand washing in preventing disease in the hospital setting

Joseph Lister

-used aseptic technique in surgery, which greatly reduced the number of post-surgical infections

Carbohydrates: (mono, di, poly)

macromolecules: very large'

carbohydrates

-combination of carbon and water

—Represented by the formula: (CH2O)n

-end with suffix-ose

—hexose: 6 carbon sugar

~glucose: The most common and univerally important hexose

~Pentose: 5 carbon sugar

—xylose: From the greek word “wood”

—lactose: important component of milk

—maltose: malt sugar

—sucrose: Table sugar or cane sugar

Polysaccharides-Chain of sugar

-contribute to structural support and protection; serve as nutrient and energy stores:

~Cellulose: Cell wall of plants and many microscopic algae

~Agar: important component of culture media

~chitin: Cell wall found in fungi

~peptidoglycan: Component of bacterial cell wall

~Lipopolysaccharide: Component of gram-negative cell wall

~glycocoalyx: protective outer layer; role in the attachment of cells to other cells or surfaces

Monosaccharide: the most basic unit of a carb-a single sugar molecule

disaccahride: two monos joined together by a glycosidic bond

lipids

-Phospholipid

-found in all membranes of our cells, including bacteria

-membrane lipids

~Hydrophilic (“water loving”) head, negative charge

~hydrophobic (water fearing) tail; uncharged

-when exposed to an aqueous (water) solution:

—charged heads are attracted to the water phase

—nonpolar tails are repelled from the water

—they naturally assume a single or double layer (bilayer)

—this behavior allows them to be the main constitutent of all membranes

Proteins

-structure and folding

-predominant organic molecules in cells

-composed of 20 different amino acids

peptide: a molecule composed of short chains of amino acids usually less than 20 amino acids

polypeptide: usually has more than 20 amino acids and is often a smaller subunit of a protein

protein: usually contains a minimum of 50 amino acids and have levels of protein structure

enzymes: Catalysts for all chemical reactions in cells

antibodies: glycoproteins with specific regions of attachment for bacteria, viruses, and other microorganisms

Native state: The functional three-dimensional form of a protein

denatured: disruption of the native state of a protein through the application of various agents

-heat

-acid

-alcohol

-some disinfectants

Nucleic acids

DNA (G, T, A, and C)

RNA (G, U, A, C)

DNA: contains a special coded genetic program (A,T, G, and C) with detailed and specific instructions for each organism’s heredity

—double stranded

—antiparallel

—hydrogen bonding: A-T and G-C

RNA: responsible for carrying out DNA’s instructions and translating the DNA program into proteins that can perform life functions A-U and G-C

1. -naming, classifying, and identification of microorganisms

   -taxonomy, nomenclature, and classification)

taxonomy: the science of classifying living things

classifications: The orderly arrangement of organisms into a hierarchy- “Do kindly place candy out for good students”

-domain

-kingdom

-phylum or division

-class

-order

-family

-genus

-species

Nomenclature: The assignment of scientific names to the various taxonomic categories and to individual organisms

—scientific names are italicized when they are written in print and underlined when they are written by hand

—when the name is abbreviated, the genus name is abbreviated to the first initial followed by a period and the full species name is written

Microbial Evolution (Eukaryote, bacteria, archaea)

phylogeny: The taxonomic scheme that represents the natural relatedness between groups of living beings

evolution

-hereditary info of living beings gradually changed through time (spontaneous and nonspontaneous)

-changes result in various structural and functional changes through many generations

-selective for those changes that favor survival and reproduction, also known as natural selection

Eukaryotic cells: animals, plants, fungi, protozoa

-contain organelles that are encased by membranes and perform specific functions

Bacteria and archae: much more adaptive to environment than we are, have a nucleoid\

-no nucleus or other organelles

-complex fine structure

-can engage in same activities as eukaryotic cells

• LUCA (Last Universal Common Ancestor):

  • Lived ~3.5–4 billion years ago.

  • Shared features between bacteria, archaea, and eukaryotes (like ribosomes, genetic code).

• Bacteria vs. Archaea:

  • Both are prokaryotic but archaea are more closely related to eukaryotes at the molecular level.

  • Archaeal transcription and translation resemble eukaryotic mechanisms.

• Eukaryotic Origins (Endosymbiosis Theory):

  • Eukaryotes evolved from a symbiotic relationship between an ancestral archaeal host and engulfed bacteria:

    • Mitochondria: from α-proteobacteria

    • Chloroplasts: from cyanobacteria (in photosynthetic eukaryotes)

  • This explains eukaryotes having both bacterial-like and archaeal-like genes.

inoculation-culture, medium (media), inoculum, inoculation

-categories of media: liquid, semisolid, solid, general-purpose, enriched, selective, differential

culture: to grow microorganisms

medium: (plural, media): nutrients for the growth of microbes

Inoculum: a small sample of microbes

inoculation: The introduction of an inoculum into media to culture microbes

-clinical specimens are obtained from:

-body fluids

-discharges

-anatomical sites

-diseased tissue

—physical state

~liquid

~semisolid

~solid

—some can be converted to liquid via heat

-chemical composition

-functional type (purpose)

general purpose media: grow as broad a spectrum of microbes as possible; generally complex

enriched media: contains something that is there in order for a certain bacteria to grow

-contains complex organic substances such as blood, serum, hemoglobin, or special growth factors for the growth of fastidious microbes

-used in the clinical labatory to encourage growth of pathogens present in low numbers allowing for biological studies to be performed

selective: contains one or more agents that inhibit the growth of a certain microbes

-isolation of a specific type of microorganism from a sample containing dozens of different species (from many to one)

-differential: Allow multiple types of organisms to grow but display visible differences in how they grow:

-variations in colony size or color

-media color changes

-production of gas bubbles

-variations often come from chemicals in the media with microbes react

incubation

Incubator: A temperature-controlled chamber to encourage the multiplication of microbes

-typical temperatures used in laboratory propagation of microorganisms: 20-45 C

-atmospheric gases such as oxygen or carbon dioxide may be required for the growth of certain microbes or cell lines

-during the incubation period, the microbe multiples and produces growth that is observable macroscopically

—initial growth is exponential then over time it slows

isolation

-colony

-based on the concept that if an individual bacterial cell is separated from other cells on a nutrient surface, it will produce a discrete mount of cells called a colony

colony: a macroscopic cluster of cells appearing on a solid medium arising from the multiplication of a single cell

isolation requires the following:

1. a medium with a firm surface

2. a petri dish

3. an inoculating loop (streak plate method)

inspection and identification

Microbes can be identified through

-microscopic appearance (shape and size)

-characterization of cellular metabolism

-determination of nutrient requirements, products given off during growth, prescence of enzymes, and mechanisms for deriving energy

-genetic and immunologic charcateristics

metric system: meter, centimeter, millimeter, micrometer, nanometer

Unit	Symbol	Equivalent in Meters (m)
Meter	m	1 m
Centimeter	cm	0.01 m
Millimeter	mm	0.001 m
Micrometer	µm	0.000001 m (1×10⁻⁶ m)
Nanometer	nm	0.000000001 m (1×10⁻⁹ m)

magnification: (power of objective x power of ocular = total magnifaction)

magnification occurs in two phases:

-real image: Formed by the objective

-virtual image: formed when the image is projected up through the microscope body to the plans of the eyepiece, the ocular lens forms a second image

• 10× ocular × 4× objective = 40× total magnification

• 10× ocular × 40× objective = 400× total magnification

• 10× ocular × 100× objective = 1000× total magnification

  -the capacity of an optical system to distinguish two adjacent objects or points from one another:

  -resolving power of the human eye: .2mm

• resolving power of the light microscope using the oil immersion lens .2 um

-bright field microscope

Bright field

-most widely used type of light microscope

-forms its image when light is transmitted through the specimen

-the specimen, being denser and opaquer than its surroundings, absorbs some of this light, and the rest of the light is transmitted directly up through the ocular

-can be used for both live, unstained material and preserved, stained/unstained material

dark field microscope

Dark field microscope

-a bright- field microscope can be adapted as a dark field microscope by adding a special disc called a stop to the condenser

-the stop blocks all light from entering the objective lens, except peripheral light that is reflected off the sides of the specimen itself

-the resulting image is a particularly striking one: brightly illuminated speciments surrounded by a dark field

-the most effective use is to visualize living cells that would be disorted by drying or heat or that cannot be stained with the usual methods

fluorescence microscope

-The fluorescence microscope is a specially modified compound micrscope furnished with an ultraviolet radiation source

—the name comes from the use of certain dyes and minerals that are flurescence. The dyes emit visiblr light when bombarded by short ultraviolet rays.

-for an image to be formed, the specimen must first be coated or placed in contact with a source of fluoresence.

-has its most useful applications in diagnosing infections and pinpointing particular cellular structures.

Confocal microscope

-the scanning confocal microscope overcomes the problem of cells or structures being too thick by using a laser beam, of light to scan various depths in the specimen and deliver a sharp image focusing on just a single plane.

-able to capture a highly focused view at any level, ranging from the surface to the middle of the cell.

-most often used on fluorescently stained specimens, but it can also be used to visualize unstained cells and tissues.

electron microscopy

TEM-the method of choice for vieweing the detailed structure of cells and virsues

-produces its image by transmitting electrons through the specimen

-because electrons cannot easily penetrate thick preparations, the specimen must be sectioned into extremley thin slices and stained or coated with metals that will increase image contrast.

-the darker areas of TEM micrographs represent the thicker parts, and the lighter areas indicate the more transparent thinner parts.

acid dyes: negative staining

-Does not stick to the specimen but settles some distance from its outer boundary, forming a silhouette.

-negativley charged cells repel the negativley charged dye and remain unstained

-smear is not heat fixed, so the distortion and shrinkage of cells are reduced.

-Also used to accentrate (highlight) a capsule.

basic dyes: positive staining

Dye sticks to the specimen and gives it color

simple vs differential and special stains

Simple stains

-only require a single dye and an uncomplicated procedure:

-cause all the cells in the smear to appear more or less the same color, regardless of type.

-reveal shape, size, and arrangement.

Differential stains

-use two differently colored dyes: The primary dye and the counterstain.

-distinguish cell types or parts

-more complex and require additional chemical reagents to produce the desired reaction.

special stains

-used to emphasize cell parts that are not revealed by conventional staining methods

-capsular staining: used to observe the microbial capsule, an unstrucred protective layer surrounding the cells of some bacteria and fungi.

-negativley stained with india ink

Flagellar staining: Used to reveal tiny, slender filaments used by bacteria for locomotion

-flagella are enlarged by depositing a coating on the outside of the filament and then staining it.

gram stain

Gram positive: Cells have thicker peptidoglycan

Gram negative: Cells have a thinner peptidoglycan layer

-differential stain

bacterial shape: cocci, rods, vibrio, spirillum

Cocci: Spherical or ball shape circumference of 1 um

Rods (bacillus): length of 2 um and a width of 1 um

vibrio: gently curved cells “jellybeans”

spirillum: sprial shaped “cavatappi noodle”

pleomorphism: Variations in cell wall structure by slight genetic or nutritional differences

Arrangement of cocci:

-single

-diplococci: pairs

-tetrads: Groups of four

-Staphylococci or micrococci: irregular clusters

Streptococci: chains

Sarcina: Cubical packet of eight, sixteen, or more cells

Arrangement of bacilli:

-single

-diplobacilli: pair of cells with ends attached

-streptobacilli: chain of several cells

-palisades: Cells of a chain remain partially attached by a small hinge region at the ends

External bacterial structures:

flagellum

-chemotaxis

pilus/pili

fimbria/fimbriae

biofilm

Appendages:

-motility: Flagella and axial filaments

Flagellum: Primary function is motility

1. filament

2. hook (sheath)

3. basal body

Chemotaxis: Movement of bacteria in response to chemical signals:

-positive chemotaxis: Movement toward a favorable chemical stimulus often a nutrient

negative chemotaxis: Movement away from a repellant

run: Rotation of flagellum counterclockwise, resulting in a smooth linear direction

tumble: reversal of the direction of the flagellum, causing the cell to stop and change course

pilus/pili: Used in conjugation between bacterial cells-transfer of DNA; well characterized in gram negative bacteria

Fimbria/fimbriae: Small, bristle-like fbers sprouting off the surface of many bacterial cells; allow tight adhesion between fimbriae and epithelial cells, allowing bacteria to colonize and infect host tissues

biofilm: Surface>cells stick to coating> as cells divide, they form a dense mat bound together by sticky extracellular deposits> additonal microbes are attracted to developing film and create a mature community with complex function

Cell envelope

-lies outside the cytoplasm

-composed of two or three basic layers that each perform a distinct function, but together act as a single protective unit

-outer membrane (in some bacteria)

-cell wall

-cytoplasmic membrane

Cell wall

peptidoglycan

-gram positive

-gram negative

peptidoglycan

-compound composed of a repeating framework of long glycan chains cross-linked by short peptide fragments

-provides a strong but flexible support framework

-pencillin targets this, only works on dividing cells

Gram positive

-thick, homogenous sheet of peptidoglycan

-contains teichoic acid and lipoteichoic acid:

—function in cell wall maintenance and enlargement

-contribute to the acidic charge on the cell surface

Gram negative cell wall and outer membrane

-single, thin sheet of peptidoglycan

-the thinness makes gram negative cells more suspectible to lysis (can rupture easier than gram +)

-the outer membrane is comparable to the plasma membrane

-gram-negative outer lipid layer has lipopolysaccharide molecules in place of some phospholipids

—the polysaccharide components act as signaling molecules

—lps are endotoxins, shedding causes fever and shock

-outer membrane of gram-negative bacteria contributes an extra barrier: resistant to certain antimicrobial chemicals; more difficult to inhibit or kill than gram +

-alchohol based compounds dissolve lipids in the outer membrane and therefore damage the cell

—alchohol swabs used to cleanse the skin before certain medical procedures

-treatment of infections caused by gram-negative bacteria requires drugs that can cross the outer membrane

identifying bacteria: gram stain and fast-acid stain

purple=gram +

pink= gram -

(look at slide 18)

Acid fast bacteria (allows you to detect TB)

-myobacterium and nocardia: Contain peptidoglycan and stain gram positive, but bulk of cell wall is composed of unique liquids

-mycolic acid: very long chain fatty acid

-found in the cell walls of acid-fast bacteria

-contributes to the pathogenicity (able to cause disease) of the bacteria

-makes bacteria highly resistant to certain chemicals and dyes such as gram stain

-if gram stain doesn’t work, use this

four major component of bacterial cytoplasmic structures

1. cytoskeleton

2. ribosomes

3. nucleoid

4. plasmids

Cytoskeleton: protein filaments that polymerize to form functional filaments that extend to full inner dimensions of the cell

-homologs of eukaryotic cytoskeletal elements have been identified in bacteria

-functions are similar as in eukryotes; partipate in cell divison, localize proteins, maintain cell shape

FtsZ: forms ring at center of a dividing cell that constricts as daughter separates.

MreB: Maintains shape by positoning peptidoglycan synthesis machinery.

CreS: maintains curve shape as seen in the genus vibrio

Bacterial ribosomes

-complex protein/RNA structures

—sites of protein synthesis

—bacterial and archaea ribosome=70S (50S+30s); weighted out in svedberg units

-bacterial ribosomal RNA; 16S rRNA in small subunit; 23S and 5S rRNA in large subunit

Bacterial nucleoid

-location of chromosome and associated proteins

-”usually” contains 1 closed circular, double-stranded DNA molecule

-supercoiling and nucleoid proteins aid in folding and structure

Bacterial plasmids

-extrachromosomal DNA that is usually small, closed circular DNA molecules

-exist and replicate independently of chromsome

-episomes-are bacterial plasmids that can integrate into chromosome; inherited during cell division

-carry genes that can confer a selective advanatge in some situations

endospore

-complex, dormant structure formed by some bacteria

-form in response to nutrient depletion

-resistant to numerous environment conditions:

—heat, UV radiation, gamma radiation, chemical disinfectants, and desiccation

Sporulation-endospore formation

-organized process that occurs over several hours

-normally starts when growth slows due to lack of nutrients

-produces a dormant cell that can persist until nutrients are available and growth resumes-can last years

Essential nutrients (macronutrients, micronutrients, organic nutrients, and inorganic nutrients)

Essential nutrient: Any substance that must be provided to an organism

macronutrients: Required in relativley large quantities and play principal roles in cell structure and metabolism:

-carbon hydrogen, and oxygen

micronutrients: Present in much smaller amounts and are involved in enzyme function and maintenance of protein structure:

-also known as trace elements

-examples: manganese, zinc, nickel

organic nutrients

-contain carbon and hydrogen atoms and are usually the products of living things

-simple organic molecules such as methane

-large polymers (carbs, lipids, proteins, and nucleic acids)

Inorganic nutrients: an atom or simple molecule that contains a combination of atoms other than C and H

How microbes eat

-autotroph

-heterotroph

Microbe type	Carbon Source	Energy Source	Example organisms
Photoautotroph	CO₂	Light	Cyanobacteria, algae
Chemoautotroph	CO₂	Inorganic chemicals	Nitrifying bacteria, sulfur bacteria
Photoheterotroph	Organic	Light	Purple non-sulfur bacteria
Chemoheterotroph	Organic	Organic chemicals	Most bacteria, fungi, protozoa, humans

transport mechanisms

-diffusion (passive/facilitated)

-osmosis (isotonic, hypotonic, hypertonic)

-active

-endocytosis (phagocytosis, pinocytosis)

Diffusion: phenomenon of molecular movement, in which atoms or molecules move in a gradient from an area of higher density or concentration to an area of lower density or concentration

-water based diffusion is osmosis

-the diffusion of water across a selecitvley permeable membrane in the direction of lower water concentration.

Facilitated diffusion: molecule binds to a specific receptor in membrane and is carried to the other side. Molecule-specific. Goes both directions. Rate of transport is limited by the number of binding sites on transport proteins.

Active: Carrier-mediated active transport; atoms or molecules are pumped into or out of the cell by specialized receptors, driven by ATP

Endocytosis: Cell encloses the subtance in its membrane

-simultaneously forms a vacuole and engulfs the substance

-phagocytosis: is a type of endocytosis

—accomplished by amoebas and white blood cells

—ingest whole cells or large solid matter

-pinocytosis: ingestion of liquids such as oils or molecules in solution

bacterial temperature ranges (psychrophile, mesophile, thermophile)

Psychrophiles:

-optimum temperature >15 c

-capable of growth at 0 C

-obligate with respect to cold and cannot grow >20 C

-storage at refrigerator temperature causes them to grow rather than inhibiting them

-natural habitats of psychrophillic bacteria, fungi, and algae are lakes, rivers, snowfields, polar ice, and the deep ocean

-rarely pathogenic

Mesophiles:

-cause diseases and infect us the most

-majority of medically signifcant microorganisms

-grow at intermediate temperatures between 20 C - 40C

-inhabitat animals, plants, soil, and water in temperature, subtropical, and tropical regions

-human pathogens have optimal temperatures between 30-40C

-thermoduric microbes

—a subcategory of mesophiles that can survive short exposure to high temperatures

—common contaminants of heated or pasturized foods

Thermophiles

-grow optimally at temperatures > 45C

-live in soil and water associated with volcanic activity, compost piles, and in habitats directly exposed to the sun

-vary in heat requirements with a range of growth of 45C-80C

-most eukaryotic forms cannot survive >60 C

-extreme thermophiles grow between 80C-121C

gases (aerobes, microaerophiles, faculative, anaerobes, anaerobes, aerotolerant, anaerobes)

-the atmospheric gases that influence microbial growth are O2 and CO2

—O2 has the greatest impact on microbial growth

—O2 is an important respiratory gas and a powerful oxidizing agent

Aerobes: Can use o2 and possess the enzymes needed to process toxic oxygen products. An organism that cannot grow without o2 is an obligate aerobe.

Microaerophiles: are harmed by normal atmospheric concentrations of O2 but require a small amount of it in metabolism

Faculative anaerobes: Do not require o2 but can use it when it is present.

Anaerobes: Lack the metabolic enzyme systems for using oxygen for respiration.

Aerotolerant anaerobes: Do not utilize oxygen but can survive and grow to a limited extent in its presence. They are not harmed by O2, mainly because they possess alternate mechanisms for breaking down peroxides and superoxide.

carbon dioxide/pH/osomotic (pressure)

-capnophiles: organisms that grow best at a higher CO2 tension than is normally present in the atmopsphere

-acidophiles: organisms that thrive in acidic environments (pH <7)

-alkalinophiles: organisms that thrive in alkaline conditions (pH >7)

-osmophiles: live in habitats with high solute concentration

-halophiles: prefer high concentration of salt

-barophiles: exist under pressure that range from a few times to over 1,000 times the pressure of the atmosphere

Symbiotic/nonsymbiotic

Symbiotic: organisms live in close nutritional relationships; required by one or both members.

-Mutualism: both members benefit

-commensalism: one partner benefits; other member non harmed

-Parasitism: parasite is dependent and benefits; host harmed

Nonsymbiotic: organisms are free-living; relationships not required for survival

-synergism: members cooperate and share nutrients.

-Antagonism: some members are inhibited or destoryed by others.

Bacterial growth

-binary fission

-rate of population growth/growth curve

—lag phase, exponential growth, station growth phase, death phase, viable nonculture state (VNC)

Binary Fission

-parent cell enlarges

-duplicates its chromsome

-starts to pull its cell envelope together to the center of the cell

-cell wall eventually forms a complete septum

-one cell becomes two

Rate of population growth/growth curve

-generation time or doubling time:

-the time required for a complete fission cycle, from parent cell to two daughter cells

-generation: increases the population by a factor of two

-as long as the environment remains favorable, the doubling effect can continue at a constant rate

Growth curve in bacterial culture

Lag phase: is a flat period of growth due to (getting adjusted to new home)

-cells are not yet multiplying at their maximum rate

Exponential phase: will continue if cells have adequate nutrients and the environment is favorable

Stationary growth phase: Cell birth and cell death rates are equal

Death phase: cells begin to die at an exponential rate due to the buildup of wastes

Viable noncultureable state: Many cells in a culture in the death phase stay alive but are dormant

-endospore

Metabolism

-pertain to all chemical reactions and physical workings of the cell (energy producing and energy consuming)

Anabolism>formation of glucose, DNA/RNA, and proteins

-any process that results in synthesis of cell molecules and structures

-a building and bond-making process that forms larger macromolecules from smaller ones

-requires the input of energy

-2 possible sources for monosaccharides, A.A., fatty acids, nitrogen bases, and vitamins:

—enter the cell from the outside as “ready-to-use” nutrients

—can be synthesized through various cellular pathways

-the degree to which an organism can synthesize its own building blocks (simple molecules) is determined by its genetic makeup, a factor that varies tremendously from group to group.

-glucose has a central role in the metabolism and energy utilization:

-major components of cellulose wall of some eukarytoes and certain glucose granules

-an intermediary in glycolysis, glucose 6-P is used to form glycogen

-peptidoglycan is a linked polymer derived from fructose 6-P from glycolysis.

-carbs ribose and deoxyribose are essential building blocks of nucleic acids

-polysaccharides are the predominant components of capsules and glycocalyx if there is enough glucose for it.

-proteins account for a large proportion of a cell’s constituents

-essential components of enzymes, cytoplasmic membrane, cell wall, and cell appendages.

DNA and RNA

-responsible for the hereditary continuity of cells and

-the overall direction of protein synthesis

Cell division takes place when:

Anabolism: Produces enough macromolecules to serve two cells

Dna replication: produces duplicate copies of the cell’s genetic material

-membrane and cell wall have increased in size

Catabolism>(aerobic, anaerobic, fermentation (ATP yield from each)

-breaks the bonds of larger molecules into smaller ones.

-releases energy

-metabolism requires enzymes to catabolize organic molecules to precursor molecules that cells then use to anabolize larger, more complex molecules

-precursor molecules are producing during catabolism and needed in large quantities for anabolism:

-reducing power: Electrons available in hydrogens of NADH and FADH2 (their reduced form)

Energy: Stored in the bonds of ATP

aerobic respiration

-32 ATPS

Anaerobic respiration

2-32 ATP

Fermentation:

-2 ATP

-catobolism can take place as long as nutrients are present and the cell is nondormant.

glycolysis (location, products in and products out)

Location: cytoplasm

Total energy yield: 2 ATPs and 2 NADHs)

• Input (per glucose):

  • Glucose

  • 2 ATP (investment)

  • 2 NAD⁺

• Output:

  • 2 Pyruvate

  • 4 ATP (net gain = 2 ATP)

  • 2 NADH

Krebs cycle (location, products in and products out)

Location: Mitochondria

Total yield per 2 pyruvate: Co2: 2

energy: 2 NADHs

-each acetyl-coA yields 1 ATP, 3 NADHs, 1 FADH2, and 2 CO2 molecules

Total yield per 2 Acetyl CoAs: Co2: 4

Energy: 2 ATPs, 6 NADHs, 2 FADH2 (if just one pyruvate, cut this in half)

-The 3C pyruvate is converted to 2 C acetyl CoA in one reaction.

• Input (per 2 pyruvate = 1 glucose):

  • 2 Acetyl-CoA

  • 6 NAD⁺

  • 2 FAD

  • 2 ADP (or GDP) + Pi

• Output:

  • 4 CO₂

  • 6 NADH

  • 2 FADH₂

  • 2 ATP (or GTP)

---

Electron transport chain (location, products in and products out)

location: mitochondria

-reduced carriers (NADH, FADH2), transfer electrons and H+ to first electron carrier in chain: NADH dehydrogenase.

-simultaneous with the reduction of the electron carriers, protons are moved to the outside of the membrane, creating a concentration gradient (more protons outside than inside cell).

-The extracellular space becomes more positivley charged and more acidic than the intracellular space.

-this results in the conversion of ADP to ATP

-Aerobic respiration yields a maximum of 3 ATPs per oxidized NADH and 2 ATPs per oxidized FADH

-this pathway is more energy efficient but requires O2

-Anaerobic respiration yields less per NADH and FADH2

enzymes

-enzyme-substrate

-coenzymes (NAD/NADH and FAD/FADH2)

-enzymes are biological catalysts

-increase the rate of chemical reactions

-don’t become apart of the products

-are not consumed in the process

-do not create a reaction

-can function repeatedly without change to structure or function

-ending in ase

-simple enzymes consist of protein alone

-conjugated enzymes contain protein and non protein parts such as:

Cofactors: either organic molecules called coenzymes or inorganic elements (metal ions) (non protein part)

substrates

-positioned for various reasons to fit into enzyme

-enzymes larger in size than the substrate and contain a pocket for substrate to lock into

-active site presented for substrate to match it

-enzymes participate directly in changes to the substrate

-consutitive enzymes are in fixed amounts in a rod shaped cell. When more substrate is added, there is no change in the number of constitutive enzymes

-regulated enzymes are induced when more substrate is added and reduced when substrates are removed (ex. insulin)

NADH and FADH: energy converters later on investing for a lot of ATP

Cellular energy (ATP)

-cells possess specialized enzymes that trap the energy present in the bonds of nutrients as they are progressivley broken:

-energy released during exergonic reactions are stored in high-energy phosphate bonds present in ATP

-ATP temporarily stores and releases the energy in these chemical bonds to fuel energonic reactions