Microbiology Exam 2

Metabolism

All chemical reactions in a cell that maintain life.

Catabolism

Breaking down molecules to release energy.

Anabolism

Building molecules using energy.

Enzymes

Proteins that speed up chemical reactions by lowering activation energy.

Competitive Inhibition

Inhibitor competes with the substrate for the active site.

Noncompetitive Inhibition

Inhibitor binds elsewhere, changing enzyme shape and preventing substrate binding.

Feedback Inhibition

A product inhibits an enzyme earlier in its pathway to regulate metabolism.

Oxidoreductase

Enzymes that transfer electrons in oxidation and reduction reactions.

Transferase

Enzymes that move functional groups between molecules.

Hydrolase

Enzymes that break bonds using water in hydrolysis.

Lyase

Enzymes that break bonds without using water.

Isomerase

Enzymes that rearrange atoms within a molecule to form an isomer.

Ligase

Enzymes that join two molecules together.

Kinase

Enzymes that transfer phosphate groups to molecules, often from ATP.

Phosphatase

Enzymes that remove phosphate groups from molecules.

Cofactors

Non-protein helpers required for enzymatic activity.

Coenzymes

Organic molecules that assist enzymes, such as vitamins like NAD+.

Enzyme Activity (Temperature)

Extreme temperatures can denature enzymes, destroying their function.

Enzyme Activity (pH)

Extreme pH changes can alter enzyme shape and functionality.

Substrate Concentration Effect

More substrate increases enzyme activity until saturation.

Substrate-Level Phosphorylation

Direct transfer of a phosphate to ADP to form ATP.

Oxidative Phosphorylation

Process using the electron transport chain to produce ATP.

Photophosphorylation

Light-driven ATP production occurring in photosynthesis.

Glycolysis Inputs

Starts with glucose and uses 2 ATP to yield pyruvate, ATP, and NADH.

Transition Reaction Output

Converts pyruvate into Acetyl-CoA, producing NADH and CO2.

Krebs Cycle Outputs

Starts with Acetyl-CoA, ends with 2 ATP, 6 NADH, 2 FADH2, 4 CO2.

Electron Transport System Purpose

Generates ATP using NADH & FADH2, with oxygen as the final electron acceptor.

Dihydroxyacetone phosphate (DHAP)

Intermediate used in lipid metabolism.

Acetyl-CoA

Key input for the Krebs cycle and fatty acid synthesis.

Pyruvic acid (pyruvate)

Can convert to Acetyl-CoA or be used in fermentation.

Glucose-6-phosphate

Used in glycolysis and pentose phosphate pathway.

Phosphoglyceric acid

Intermediate formed during glycolysis.

Phophoenolpyruvic acid

Helps generate ATP during glycolysis.

Oxaloacetatic acid

Critical molecule in the Krebs cycle.

α-ketoglutaraic acid

Krebs cycle intermediate, involved in amino acid synthesis.

Pentose Phosphate Pathway

Produces NADPH and ribose for DNA/RNA synthesis.

Entner-Doudoroff Pathway

An alternate glycolysis pathway utilized by some bacteria.

Fermentation Process

Converts pyruvate into waste products, producing 2 ATP per glucose.

Alcohol Fermentation Products

Produces ethanol and CO2, commonly by yeast.

Acidic Fermentation Product

Produces lactic acid, as seen in muscle cells and some bacteria.

Aerobic Respiration ATP Yield

Produces 28-38 ATP.

Anaerobic Respiration ATP Yield

Produces about 2-36 ATP, less than aerobic respiration.

Fermentation ATP Yield

Produces only 2 ATP per glucose, least efficient energy production.

Aerobic Respiration Final Electron Acceptor

Oxygen (O2) serves as the final electron acceptor.

Anaerobic Respiration Final Electron Acceptors

Nitrate (NO3), sulfate (SO4), and carbonate (CO3) are used.

Fermentation Final Electron Acceptor

Pyruvate acts as the final electron acceptor.

Oxygenic Photosynthesis

Process that produces O2, found in plants and cyanobacteria.

Anoxygenic Photosynthesis

Photosynthesis that does not produce oxygen, found in some bacteria.

Calvin Cycle Importance

Uses CO2, ATP, and NADPH for glucose production, essential for carbon fixation.

DNA Replication Start

Initiated at the origin of replication by helicase unzipping DNA.

Leading Strand Synthesis

Continuous DNA synthesis toward the replication fork.

Lagging Strand Synthesis

Discontinuous synthesis in sections called Okazaki fragments.

Transcription Process Similarity

Both prokaryotes and eukaryotes use RNA polymerase for mRNA synthesis.

Prokaryotic Transcription/Translation

Simultaneous processes in the cytoplasm with no mRNA processing.

Eukaryotic Transcription/Translation

Transcription in the nucleus, translation in the cytoplasm, with mRNA processing.

Silent Mutation

No change in amino acid sequence due to codon redundancy.

Missense Mutation

Change in a single amino acid which might alter protein function.

Nonsense Mutation

Premature stop codon creating a truncated, likely non-functional protein.

Frameshift Mutation Effect

Insertion or deletion shifts reading frame, changing all subsequent codons.

Operon Structure

Includes promoter, operator, and structural gene sequences.

Lac Operon Control

No lactose activates repressor; lactose presence inactivates repressor, allowing transcription.

Tryptophan Operon Control

Low tryptophan allows operon function; high tryptophan activates repressor, blocking transcription.

Transformation Process

Uptake of foreign DNA by bacteria from their environment.

Transduction Process

Bacteriophage transfer of genetic material between bacteria.

Conjugation (F + x F -)

Direct transfer of genetic material between bacteria using a pilus.

Conjugation (Hfr x F -)

High-frequency recombination transfer of chromosomal DNA to a recipient.

Transposons (Jumping Genes)

Mobile DNA segments that can insert into genes causing mutations.

Purpose of Restriction Enzymes

Cut DNA at specific sequences for cloning and genetic engineering.

PCR Process (Denaturation)

Heat is used to separate DNA strands.

PCR Process (Annealing)

Primers bind to target DNA at lower temperatures.

PCR Process (Extension)

DNA polymerase adds nucleotides to the growing DNA strand.

Regular PCR

Amplifies DNA by repeated cycles of denaturation, annealing, and extension.

RT-PCR

Converts RNA into complementary DNA before amplification.

Real-time PCR (qPCR)

Measures DNA amplification during PCR in real-time.

DNA Sequencing Purpose

Determines the order of nucleotides for research and diagnostics.

Sanger Sequencing

Uses labeled nucleotides for accurate but slow DNA sequencing.

Next-Gen Sequencing

High-speed, parallel sequencing of DNA.

RNA Seq Purpose

Sequences mRNA to analyze gene expression.

Microbiome Role

Prevents pathogen activity by competing for resources and producing antimicrobials.

Portals of Entry for Pathogens

Routes like skin breaches, mucous membranes, and parenteral entry into tissues.

ID50

Infectious Dose 50, number needed to infect 50% of a population.

LD50

Lethal Dose 50, amount needed to kill 50% of a population.

Virulence Factors Importance

Assist pathogens in infecting, spreading, and evading immune response.

Endotoxin

Gram-negative bacterial component that causes systemic effects upon death.

Exotoxin

Secreted toxin from bacteria, causing specific harmful effects.

Methods of Exit for Organisms

Include respiratory droplets, feces, urine, blood, and sexual fluids.

Stages of Infectious Disease

Incubation, prodromal, acute, convalescent, and continuation phases.

Communicable Disease

Infectious disease transmissible between individuals.

Noncommunicable Disease

Disease not transmitted between individuals.

Local Disease

Infection confined to a specific area.

Focal Disease

Local infection that spreads to other areas.

Systemic Disease

Disease that affects the entire body.

Acute Disease

Fast onset and short duration of illness.

Chronic Disease

Long-lasting illness requiring ongoing management.

Bacteremia

Presence of bacteria in the blood without multiplication.

Septicemia

Multiplication of bacteria in the blood leading to severe infection.

Primary Infection

Initial infection, such as a viral disease.

Secondary Infection

Infection following a primary one, exploiting weakened immunity.

Direct Contact Transmission

Physical touch transmitting pathogens.

Congenital Transmission

Pathogen transfer from mother to child during pregnancy or birth.