HCC Microbiology 107 Final Review Flashcards

A comprehensive set of 170 flashcards focused on key concepts in microbiology, designed to aid in studying for the HCC Microbiology 107 final exam.

What is the main structural difference between prokaryotic and eukaryotic cells?

Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.

What are the four major types of microorganisms studied in microbiology?

Bacteria, Archaea, Fungi, and Viruses.

Which microorganisms are prokaryotic?

Bacteria and Archaea.

Which microorganisms are eukaryotic?

Fungi and protists.

Which microorganisms are acellular?

Viruses.

Define biogenesis.

The principle that living organisms arise only from other living organisms.

Define abiogenesis.

The disproven idea that life arises spontaneously from nonliving matter.

What is the correct order of taxonomic classification?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What is binomial nomenclature?

Two-part scientific naming system: Genus species (italicized).

What is a dilution factor?

The ratio of the volume transferred divided by total volume in a dilution tube.

How do you calculate original cell density (OCD)?

OCD = colony count / (dilution × volume plated).

Name the three subatomic particles.

Protons, neutrons, electrons.

Where are protons located?

In the nucleus.

What is the mass and charge of an electron?

Mass ≈ 0 amu; charge = –1.

Define atomic number.

Number of protons in an atom.

Define isotope.

Atoms of the same element with different numbers of neutrons.

What is a covalent bond?

A chemical bond formed by sharing electrons.

What is an ionic bond?

A bond formed by transfer of electrons between atoms.

Define oxidation.

Loss of electrons.

Define reduction.

Gain of electrons.

What type of bond forms between oxygen and hydrogen within a water molecule?

Polar covalent bonds.

What type of bond forms between two water molecules?

Hydrogen bonds.

pH < 7 indicates what?

An acidic solution (high H⁺ concentration).

pH > 7 indicates what?

A basic solution (high OH⁻ concentration).

Define monomer.

A single building block of a macromolecule.

Define polymer.

A large molecule made of repeating monomers.

What is dehydration synthesis?

Reaction that joins monomers by removing water.

What is hydrolysis?

Reaction that breaks polymers by adding water.

Name five biologically important monosaccharides.

Glucose, fructose, galactose, ribose, deoxyribose.

Name three important disaccharides.

Sucrose, lactose, maltose.

Name four important polysaccharides.

Starch, glycogen, cellulose, chitin.

What are the building blocks of fats and oils?

Glycerol and fatty acids.

What is the difference between saturated and unsaturated fats?

Saturated fats have no double bonds; unsaturated fats have one or more.

What are trans fats?

Hydrogenated unsaturated fats with trans double bonds; unhealthy.

What are the components of an amino acid?

Central carbon, amino group, carboxyl group, R group.

What bond links amino acids together?

Peptide bond.

Name the four levels of protein structure.

Primary, secondary, tertiary, quaternary.

What are the three components of a nucleotide?

Sugar, phosphate, nitrogenous base.

Name the purines.

Adenine (A), Guanine (G).

Name the pyrimidines.

Cytosine (C), Thymine (T), Uracil (U).

What base pairs with adenine in DNA?

Thymine.

What base pairs with adenine in RNA?

Uracil.

What enzyme unwinds DNA during replication?

Helicase.

What enzyme builds new DNA strands?

DNA polymerase.

What enzyme joins Okazaki fragments?

DNA ligase.

Define transcription.

The process of making mRNA from DNA.

Define translation.

The process of making a polypeptide from mRNA at a ribosome.

What is a codon?

A three-nucleotide mRNA sequence coding for an amino acid.

What is an anticodon?

A three-base sequence on tRNA complementary to an mRNA codon.

What is a point mutation?

A single nucleotide change in DNA.

What is a missense mutation?

A point mutation that changes one amino acid in the protein.

What is a nonsense mutation?

A point mutation that creates a premature stop codon.

What is a frameshift mutation?

Insertion or deletion of nucleotides not divisible by 3, shifting the reading frame.

What are the three forms of horizontal gene transfer?

Transformation, conjugation, and transduction.

Define transformation (in bacteria).

Uptake of naked DNA from the environment.

Define conjugation.

DNA transfer between bacterial cells via a sex pilus.

Define transduction.

Transfer of bacterial DNA by bacteriophages.

What enzymes remove RNA primers in DNA replication?

DNA polymerase I (bacteria) or RNase H (eukaryotes).

What is the difference between the bacterial chromosome and plasmids?

Chromosome contains essential genes; plasmids carry nonessential but advantageous genes.

What is the nucleoid in bacteria?

Irregular region containing the bacterial chromosome.

What are inclusion bodies?

Storage structures for nutrients like glycogen, sulfur, phosphate.

Name two genera of bacteria capable of forming endospores.

Bacillus and Clostridium.

What triggers sporulation in bacteria?

Harsh conditions such as nutrient depletion.

What is germination (endospore)?

Return of a dormant endospore to a metabolically active vegetative cell.

Describe Gram-positive cell walls.

Thick peptidoglycan with teichoic acids.

Describe Gram-negative cell walls.

Thin peptidoglycan, outer membrane with LPS, periplasmic space.

What does LPS stand for and where is it found?

Lipopolysaccharide, found in the outer membrane of Gram-negative bacteria.

What is endotoxin?

Toxic portion of LPS (Lipid A).

Why do Gram-negative bacteria resist some antibiotics?

Their outer membrane blocks drug entry.

Why must cells remain small?

To maintain a high surface area–to–volume ratio for efficient transport.

What cell organelle produces ATP in eukaryotes?

Mitochondria.

What structure is unique to plant cells?

Chloroplasts.

What is simple diffusion?

Passive transport of molecules from high to low concentration without proteins.

Which molecules diffuse directly through membranes?

Small nonpolar molecules (O₂, CO₂) and some lipids.

Define osmosis.

Movement of water across a semipermeable membrane toward higher solute concentration.

Define isotonic solution.

Solute concentration equal inside and outside cell.

Define hypertonic solution.

Higher solute concentration outside; cell loses water.

Define hypotonic solution.

Lower solute concentration outside; cell gains water.

What happens to animal cells in hypotonic solutions?

They can swell and burst (lysis).

What happens to plant cells in hypotonic solutions?

They become turgid (ideal condition).

What is facilitated diffusion?

Passive transport using carrier or channel proteins.

What is active transport?

Movement of molecules against concentration gradient using ATP.

What is binary fission?

Asexual cell division in prokaryotes resulting in two identical daughter cells.

What is chromatin?

Uncondensed DNA in the nucleus.

What are sister chromatids?

Identical copies of a chromosome connected at the centromere.

Define homologous chromosomes.

Chromosome pairs with the same genes but possibly different alleles.

What is the kinetochore?

Protein complex where spindle fibers attach.

What does diploid (2n) mean?

Two sets of chromosomes.

What does haploid (1n) mean?

One set of chromosomes.

Name the phases of the cell cycle.

G1, S, G2, M.

During which phase is DNA replicated?

S phase.

During which phase do chromosomes line up at the metaphase plate?

Metaphase.

During which phase do sister chromatids separate?

Anaphase.

Define allele.

Different forms of a gene.

Define genotype.

Genetic makeup (e.g., AA, Aa, aa).

Define phenotype.

Physical expression of genotype.

Define homozygous.

Two identical alleles (AA or aa).

Define heterozygous.

Two different alleles (Aa).

What is incomplete dominance?

Heterozygous phenotype is intermediate (pink flowers).

What is codominance?

Both alleles expressed equally (AB blood type).