Module 8

Metabolism

Metabolism

All chemical reactions occurring within a cell (intracellularly)

Metabolic Enzymes

Proteins that are biologic catalysts that enhances metabolism.

Catabolism

It is a aerobic respiration that breaks down of bonds in compounds to release energy

Glycolysis

Breakdown of glucose molecules to pyruvic acids (pyruvates)

Krebs Cycle

Series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate. Produces 2 ATP molecules.

Electron Transport Chain

Chemicals produced in Krebs cycle enters in this process (oxidative phosphorylation) which converts ADP to ATP. In Eukaryotes, both Krebs cycle and ETC happens in the mitochondria. It produces 32 ATP in prokaryotes and 34 in eukaryotes.

Phototrophs

They uses light for energy

Photoautotrophs

Make their own energy using light and CO2 through photosynthesis. Used in cellular reactions

Photoheterotrophs

It has a photosynthetic components, enabling them to capture light and use it as their energy source. Use light and carbon from organic materials and not from CO2.

Chemotrophs

Oxidation of inorganic molecules.

Lithotrophs

It uses inorganic substrates for energy.

Organotrophs

It uses organic molecules as an energy source. It obtains hydrogen or electrons from organic substrate.

Chemoautotrophs

These are cells that create their own energy and biological materials from inorganic chemicals (CO2). They do not have any photosynthetic pigments, their primary source of energy are different chemicals.

Chemoheterotrophs

They do not have any photosynthetic pigments. They also unable to utilize CO2

Autotrophs

It utilizes CO2 as primary and only source of carbon.

Heterotrophs

It utilizes organic compounds other than CO2 as carbon source.

Anabolism

Creation of bonds by combining smaller molecules to form larger ones, requiring energy

Enzymes

Proteins that act as biological catalysts, enhancing metabolism

Biological Catalyst

Proteins that catalyze the rate of biochemical reactions. In some cases, biochemical reactions will not occur at all in the absence of an enzyme.

Specificity

A particular enzyme can only exert its effect or act on one particular substances known as substrate for that enzyme.

Endoenzymes

Digestive enzymes in lysosomes and phagocytes.

Exoenzymes

Released in the environment which includes proteases, lipases, and amylase.

Microbial Growth

Increase in the number of microorganisms in a population

Physiology

Study of the vital processes or different life processes happening within an organism.

Microbial Physiology

Study of the vital processes or different life processes happening within a microorganism.

Factors of Microbial Growth

Various conditions that affect the growth of microorganisms, including availability of nutrients, moisture, temperature, pH level, and osmotic pressure

Cease Growing

Microorganisms when exposed below their minimum temperature will experienced?

Die

Microorganisms when exposed above their maximum temperature will experienced?

Thermophiles

Microorganisms that grow best in high temperature.

Minimum: 25 C

Optimum: 50 - 60 C

Maximum: 113 C

Mesophiles

Microorganisms that grow best at moderate temperature.

Minimum: 10 C

Optimum: 20 - 40 C

Maximum: 45 C

Psychrophiles

Microorganisms that prefer cold temperature.

Minimum: -5 C

Optimum: 10 - 20 C

Maximum: 30 C

Acidophiles

Microorganisms that live in acidic environments such as stomach and in pickled foods. They prefer a pH of 2-5.

Alkaliphiles

Microorganisms that live in alkaline environment with pH level >7.

Hypertonic Solution

The environment is overly saturated which can result in crenation.

Plasmolysis

The condition in hypertonic solutions where the microorganism’s cell membrane and cytoplasm shrink away from cell wall.

Hypotonic Solution

Environment that lacks solute which can result in lysis.

Plasmoptysis

When microorganisms are placed in hypotonic solutions, the cell ruptures. In this case, the cytoplasm escape from the cell.

Isotonic Solution

Balanced between the concentration extra- and intracellularly.

Piezophiles

Microorganisms that thrive in high atmospheric pressure like deep in the ocean and oil wells.

Heat

The most practical, efficient, and inexpensive method of sterilization of those inanimate objects and materials that can withstand high temperature.

Thermal Death Point

The lowest temperature to kill all microorganisms in a standard pure culture.

Thermal Death Time

It is the length of time-sterilize pure culture at a specified temperature.

Dry Heat

It refers to the baking in a thermostatically controlled oven which provides effective sterilization of metals, glassware, some powders, oils, and waxes.

Incineration

An effective means of destroying contaminated disposable materials; similar to the process of baking.

Moist Heat

The heat is applied in the presence of moisture, as in boiling or steaming.

Freezing/Cold

Most microorganisms are not killed by cold temperature and freezing, but their metabolic activities are slowed, greatly inhibiting their growth.

Desiccation

Dehydration substances to kill bacteria since water is necessary for them to metabolize. Not a reliable method since a lot of microbes despite being dried, is still present in blood, pus, fecal materials, and dust.

Capnophiles

They can withstand desiccation since they survive on carbon dioxide and the lack of moisture.

Lyophilization

Use of both freezing and desiccation. It cannot be used to prevent them from reproducing and to store them for future use.

Radiation

Use of sunlight/UV lamp to eradicate microbial growth

Ultrasonic Waves

Frequently used in cleaning delicate equipment. They consists of tanks filled with liquid solvent; the short sound waves mechanically dislodge debris on instruments and glassware.

Filtration

Filters if various pore sizes are used to filter or separate cells; larger viruses, bacteria, and certain other microorganisms from the liquids or gases in which they are suspended.

Sterilization

Involves the destruction or elimination of all microbes including cells, spores, and viruses.

Disinfection

The elimination of most pathogens from nonliving objects.

Disinfectants

Chemicals used to disinfect inanimate objects but do not kill spores. Furthermore, it cannot be used on living tissue.

Microbicidal Agents

Disinfectants or antiseptics that kill microbes.

Microbiostatic Agents

A drug or chemical hat inhibits the reproduction of microorganism, but does not necessarily killing them.

Antiseptics

Chemical solutions used to disinfect skin and other living tissues.

Sanitation

Reduction of microbial populations to levels considered safe by public health standards.

Sepsis

It refers to the presence of pathogens in the blood o tissues.

Asepsis

It refers to the absence of pathogens

Antisepsis

It refers to prevention of infection.

Drug Resistance

Ability of microorganisms to withstand the effects of antimicrobial drugs, making them less effective in treating infections

Superbugs

Organisms that are resistant to multiple antimicrobial agents, making infections caused by them difficult to treat

Inhibition of Microbial Growth In Vitro

Methods and techniques used to prevent the growth of microorganisms in laboratory settings

Inhibition of Microbial Growth In Vivo

Strategies and approaches used to inhibit the growth of microorganisms within a living organism

Antimicrobial Agents

Chemicals or drugs used to treat infections caused by microorganisms, including bacteria, fungi, protozoa, and viruses

β-Lactamases

Enzymes produced by some bacteria that destroy the β-Lactam ring in antibiotics, leading to resistance against these drugs

Drug Stability

It is the capacity of a drug to maintain specifications and potency.

Anaphylaxis

It is the severe allergic reaction that occur within 1 hour AB administration

Adverse Reaction

It is the response to a drug which is noxious and unintended, and which occurs, at doses, normally used in a man for prophylaxis, diagnosis, or therapy of disease, or for the modifications of physiological functions.

Side Effect

It is the unintended effect occurring at a normal dose related to the pharmacological properties. It can resolve on their own with time.

5 Basic Mechanism of Action of Antimicrobials

1. Inhibition of cell wall synthesis

2. Damages cell wall membrane

3. Inhibition of RNA and DNA synthesis

4. Inhibition of protein synthesis

5. Inhibition of enzymatic activity

Narrow-Spectrum Antibiotics

Type of antibiotics that kills either Gram-positive or -negative bacteria (Gram specific). It also targets few types of bacteria. Penicillin and vancomycin are example of this antibiotics.

Broad-Spectrum Antibiotics

Type of antibiotics that kills both Gram-positive and -negative bacteria. It also targets many types of bacteria. Furthermore, using when not needed can create antibiotic-resistant bacteria that are hard to treat.

Penicillins

Bactericidal that interferes with synthesis of bacterial cell walls. They are also referred to as B-lactam drugs because their molecular structure includes a four-sided ring structure known as B-lactam ring.

Cephalosporins

Beta-lactam antimicrobials that interfere with cell wall synthesis.

First Generation

Active against Gram-positive bacteria which has narrow spectrum.

Second Generation

Increased activity against Gram-negative bacteria and slightly less activity against Gram-positive.

Third Generation

Greater activity against Gram-negatives and has reasonable effect against Gram-positives.

Fourth Generation

Active against Gram-positive/negative bacteria including Psuedomonas aeruginosa it also has broad spectrum activity.

Fifth Generation

Broad spectrum activity like fourth generation and is active against MRSA (Methicillin-resistant Staphylococcus aureus)

Tetracyclines

Broad spectrum, bacteriostatic drugs. It targets bacterial ribosomes by inhibiting protein synthesis. It bind to the portion of ribosomes 30s subunit.

Aminoglycosides

Bactericidal, broad spectrum drugs. They inhibit protein synthesis, same as with tetracyclines.

Macrolides

Dosage-dependent. It can be bacteriostatic at lower doses and bactericidal at higher doses. It works by inhibiting protein synthesis by binding with the 50s subunit of bacteria.

Flouroquinolones

Bactericidal that inhibits DNA synthesis.

Antifungal Agents

Drugs used to treat fungal infections. It works in one of the three functions

1. by binding with cell membrane sterols

2. by interfering with sterol synthesis

3. by blocking mitosis or nucleic acid synthesis

Antiprotozoal Agents

Drugs used to treat protozoal infections. They work by interfering with DNA and RNA synthesis.

Antiviral Agents

Drugs used to treat viral infection. Difficult to develop and use because viruses are produced within host cell.