Key Concepts in Microbiology and Molecular Biology pt. 1

What are molds?

Multicellular fungi with filamentous hyphae that form mycelium.

What are yeasts?

Unicellular fungi that reproduce by budding or fission.

What is a saprobe?

An organism that feeds on dead/decaying organic matter.

What is the range of visible light wavelength?

400-700 nanometers.

What are biofilms?

Communities of microbes on a surface, embedded in a protective matrix.

Define anabolic reaction.

Builds complex molecules and uses energy (e.g., protein synthesis).

Define catabolic reaction.

Breaks down molecules and releases energy (e.g., glycolysis).

What do photoautotrophs use for energy and carbon?

Light energy and CO₂.

What is the streak plate method used for?

Isolating pure colonies on solid media.

What is the pour plate method used for?

Growing colonies inside and on top of agar.

What is the central dogma of molecular biology?

DNA → RNA → Protein.

What types of RNA are involved in translation?

mRNA, tRNA, rRNA.

What are nucleotide analogs?

Fake nucleotides that cause mutations when inserted into DNA.

What is semi-conservative DNA replication?

Each new DNA molecule has one old strand and one new strand.

What direction does DNA polymerase synthesize DNA?

5' to 3' direction.

What is the leading strand?

DNA strand synthesized continuously.

What is the lagging strand?

DNA strand synthesized in Okazaki fragments.

Name types of plasmids.

Fertility (F), Resistance (R), Virulence, Bacteriocin.

What does reverse transcriptase do?

Converts RNA into complementary DNA (cDNA).

What do restriction enzymes do?

Cut DNA at specific sequences.

What is PCR used for?

Amplifying DNA segments.

What machine is used in PCR?

Thermocycler.

What is biotechnology?

Using living organisms to make products (e.g., insulin, GMOs).

Name a natural method for inserting DNA into cells.

Transformation, conjugation, or transduction.

Name an artificial method for inserting DNA into cells.

Electroporation, microinjection, gene gun.

What do mutagens do?

Cause changes in DNA (mutations).

What causes tuberculosis?

Mycobacterium tuberculosis.

How do prokaryotic cells reproduce?

Asexually, mostly by binary fission.

What causes cocci to form chains or clusters?

Binary fission in different planes.

What are endospores?

Dormant, resistant structures formed by Bacillus and Clostridium.

Why are endospores a concern in healthcare?

They resist heat, drying, disinfectants — hard to kill.

What does Bergey's Manual contain?

Classification of prokaryotes by traits like staining and genetics.

What pigment do algae use for photosynthesis?

Chlorophyll a.

How do algae reproduce sexually?

By forming gametes.

What happens in mitosis?

One diploid nucleus divides into two diploid nuclei.

What happens in meiosis I?

Diploid nucleus divides into two haploid nuclei.

What happens in meiosis II?

Two haploid nuclei divide into four haploid nuclei.

When does DNA replication occur?

Before prophase, during interphase.

What are arachnids and how are they relevant?

Ticks and mites — disease vectors (e.g., Lyme disease).

What are prions?

Infectious proteins with no nucleic acids.

What is a virion?

A complete virus particle.

What gives a virus its shape?

The capsid (protein coat).

What types of genetic material do viruses have?

DNA or RNA, single- or double-stranded.

What is a bacteriophage?

A virus that infects bacteria.

Can you see viruses with a light microscope?

No, they are too small — need electron microscope.

How are viruses cultured in labs?

Using embryonated eggs, cell cultures, or live animals.

What is host specificity in viruses?

The virus only infects cells with compatible receptors.

What is a viral plaque assay?

A method to measure virus quantity — clear zones = plaques.

What are viroids?

Small, circular RNA molecules that infect plants.