FINAL EXAM LECTURE 1

What is a microbe/microorganism?

An organism that cannot be seen with the naked eye, only with a microscope.

What is immunology?

The study of the parts of the human body that protect us from microbes.

What is epidemiology?

The study of the control and spread of diseases.

What is bacteria classified as?

Cellular, prokaryotic, unicellular.

What are helminths classified as?

Cellular, eukaryotic, multicellular.

What did Antony van Leeuwenhoek contribute to microbiology?

Made the first microscope lens to see microorganisms.

What did Louis Pasteur discover?

Disproved spontaneous generation using swan-neck flask; proved life comes from life.

What did Robert Koch contribute to microbiology?

Linked anthrax to a specific pathogen.

What did Ignaz Semmelweis promote?

Handwashing in hospitals after observing infection rates.

What did Joseph Lister develop?

Aseptic technique during surgery.

What did Carolus Linnaeus develop?

Classified organisms based on physical traits into taxa.

What is WHO?

World Health Organization – monitors and controls global diseases.

What is CDC?

Centers for Disease Control and Prevention – monitors and controls diseases in the U.S.

What is the mnemonic for taxonomical groups?

Dear King Phillip Came Over For Good Spaghetti.

How do you write a scientific name in binomial nomenclature?

Genus capitalized, species lowercase, italicized or underlined.

What are the two properties of a microscope?

Magnification (enlarges specimen) and resolution (clarity of image).

What is the charge on the outside of a microbe?

Negative.

What is a negative stain?

Background is stained, bacteria remain clear.

What is a positive stain?

Bacteria are stained.

What type of stain is the Gram stain?

Differential stain using two dyes to determine Gram-positive or Gram-negative.

Why is the Gram stain clinically important?

It helps determine which antibiotics to use.

What is aseptic technique?

Prevents contamination of people, environment, and specimens.

What is sterile?

Free from all microorganisms.

What is added to media to make it solid?

Agar.

What is an example of general purpose media?

Nutrient agar.

What is an example of enriched media?

Blood agar.

What is an example of selective media?

MacConkey agar (MAC).

What is an example of differential media?

MacConkey agar (MAC).

What shape is bacillus?

Rod-shaped.

What shape is coccus?

Spherical.

What shape is vibrio?

Comma-shaped.

What shape is spirochete?

Spiral, corkscrew-shaped.

What is streptococcus?

Chains of spherical cells.

What is staphylococcus?

Clusters of spherical cells.

What is streptobacillus?

Chains of rod-shaped cells.

What is the nucleoid region?

Region where bacterial DNA is stored.

What is the function of ribosomes?

Protein synthesis.

What does the cell membrane do?

Regulates transport of molecules in and out.

What is the function of the cell wall?

Provides protection and shape.

What is the function of fimbriae?

Attachment to surfaces or host cells.

What is the capsule's function?

Helps form biofilms and evade the immune system.

What structure is used for bacterial movement?

Flagella.

How do bacteria move with flagella?

Counterclockwise = straight run or tumble.

How do bacteria move without flagella?

Brownian motion (random vibration).

Difference between Gram-positive and Gram-negative bacteria?

Gram+ = thick peptidoglycan, purple stain; Gram- = thin peptidoglycan, red/pink stain.

What is a vegetative cell?

Active, metabolizing, reproducing cell.

What is an endospore?

Dormant, non-reproductive, and non-metabolizing form.

What is the structure of a naked virus?

Genome and protein capsid.

What is the structure of an enveloped virus?

Genome, capsid, and outer membrane (envelope).

What is a prion?

Infectious protein.

What diseases do prions cause?

Neurodegenerative diseases.

Differences: Prokaryote vs. Eukaryote vs. Virus?

Prokaryotes: no nucleus/organelles; Eukaryotes: nucleus/organelles; Viruses: acellular, need host to reproduce.

What are photoautotrophs?

Use light for energy and CO₂ for carbon.

What are chemoautotrophs?

Use chemicals for energy and CO₂ for carbon.

What are photoheterotrophs?

Use light for energy and organic compounds for carbon.

What are chemoheterotrophs?

Use chemicals and organic compounds for energy and carbon.

What is active transport?

Movement from low to high concentration, needs energy and a protein.

What is simple diffusion?

Movement from high to low, no energy or protein needed.

What is facilitated diffusion?

Movement from high to low, needs a transport protein.

What is osmosis?

Movement of water across a membrane.

What temperature do psychrophiles grow at?

-15°C to 20°C.

What temperature do mesophiles grow at?

20°C to 50°C.

What temperature do thermophiles grow at?

45°C to 80°C.

What temperature do hyperthermophiles grow at?

67°C to 105°C.

What is an obligate aerobe?

Requires oxygen to grow.

What is a facultative anaerobe?

Can grow with or without oxygen.

What is an obligate anaerobe?

Dies in the presence of oxygen.

What is a halophile?

Prefers high salt environments.

Which organism is likely found in necrotic tissue?

Obligate anaerobe.

What structure is needed to form a biofilm?

Capsule.

What are beneficial biofilms?

Normal flora and respiratory mucosa.

What are harmful biofilms?

Dental plaque causing gingivitis.

What advantages do biofilms provide bacteria?

Protection from immune system and antibiotics.

What type of macromolecule are enzymes?

Proteins.

What do enzymes do?

Speed up chemical reactions by lowering activation energy.

How do enzymes work?

Bind specific substrates at the active site to catalyze reactions.

What is denaturation in enzymes?

Structural change (due to heat, pH, etc.) that causes enzyme to lose function.

What is the purpose of NADH in the cell?

Electron carrier that transports electrons to the electron transport chain.

What is the function of ATP in the cell?

Main energy currency used to power cellular processes.

What happens during glycolysis?

Glucose is broken into 2 pyruvate; 2 ATP and 2 NADH made.

What happens in the Krebs cycle?

Pyruvate is broken down; CO₂ released, NADH and FADH₂ produced.

What happens in the electron transport system (ETS)?

Electrons from NADH and FADH₂ move through proteins; H⁺ pumped out.

What does ATP synthase do?

Uses proton gradient to make ATP from ADP.

Total ATP made from aerobic respiration?

About 36–38 ATP per glucose molecule.

Three processes bacteria use to turn food into energy?

Aerobic respiration, anaerobic respiration, fermentation.

Which energy processes are used by obligate aerobes?

Aerobic respiration only.

Which energy processes are used by facultative anaerobes?

Aerobic respiration, anaerobic respiration, and fermentation (depending on O₂).

Main difference between aerobic and anaerobic respiration?

Final electron acceptor: O₂ in aerobic; non-O₂ molecule in anaerobic (e.g., nitrate).

Which fermentation step is shared with aerobic respiration?

Glycolysis.

How much ATP is made in fermentation?

2 ATP per glucose molecule

What are the stages for bacterial growth?

Lag phase, Exponential phase, Stationary phase, Death phase.