Simplified comprehensive final exam objectives

What is the difference between prokaryotic and eukaryotic cells?

Prokaryotes have no nucleus or membrane-bound organelles; eukaryotes have both.

Which organisms are prokaryotes?

Bacteria and archaea.

Which organisms are eukaryotes?

Fungi, protozoa, helminths, plants, animals.

What are viruses and prions?

Nonliving infectious particles. Viruses contain DNA or RNA; prions are misfolded proteins.

How do microbes affect Earth?

They recycle nutrients, make oxygen, decompose waste, help digestion, cause and prevent disease.

What is a biofilm?

Sticky communities of microbes that attach to surfaces and resist antibiotics.

How do humans use microbes?

Making food, medicines, vaccines, cleaning pollution, genetic engineering.

What is natural selection?

Traits that help survival get passed on.

What do phylogenetic trees show?

Evolutionary relationships.

Why is rRNA used in taxonomy?

It changes slowly and shows deep evolutionary relationships.

What are the three domains?

Bacteria, Archaea, Eukarya.

What is a virulence factor?

Anything that helps a microbe cause disease.

What shapes do bacteria have?

Cocci, bacilli, spirals.

What are bacterial arrangements?

Pairs, chains, clusters, palisades.

What do bacterial flagella do?

Movement.

What do fimbriae do?

Attachment.

What does a pilus do?

Transfers DNA.

What is a glycocalyx?

Sticky coating for protection and adhesion.

What is the bacterial cell membrane?

Phospholipid bilayer that controls transport.

Gram-positive vs gram-negative?

Gram+ = thick peptidoglycan. Gram– = thin peptidoglycan + outer membrane with LPS.

Why is the outer membrane important?

Contains endotoxin (LPS) and makes drugs less effective.

What is the bacterial chromosome?

One circular DNA molecule.

What is a plasmid?

Extra DNA with helpful genes like antibiotic resistance.

What do ribosomes do?

Make proteins.

What are inclusion bodies?

Storage.

What are microcompartments?

Protein shells that organize reactions.

What is the bacterial cytoskeleton?

Internal support and shape.

What is an endospore?

Tough, dormant cell that survives extreme conditions.

Why are endospores clinically important?

Hard to kill and cause serious disease (anthrax, tetanus, C. diff).

What do eukaryotic flagella and cilia do?

Movement.

What is the eukaryotic glycocalyx?

Protection and recognition.

How is the eukaryotic cell wall different from bacteria?

Made of cellulose/chitin instead of peptidoglycan.

What is the nucleus?

Stores DNA.

What does the ER do?

Rough ER makes proteins; smooth ER makes lipids.

What does the Golgi do?

Packages and ships molecules.

What is a eukaryotic ribosome?

80S; bigger than bacterial (70S).

Why does ribosome difference matter clinically?

Some antibiotics target 70S ribosomes without harming human 80S.

What do mitochondria do?

Make ATP.

What do chloroplasts do?

Photosynthesis.

What does the cytoskeleton do?

Structure and movement.

What do lysosomes do?

Digestion.

What do peroxisomes do?

Detoxify.

What do vacuoles/vesicles do?

Storage and transport.

How do the nucleus, ER, and Golgi work together?

DNA → mRNA → protein made in ER → packaged by Golgi → sent in vesicles.

What is the endosymbiotic theory?

Mitochondria/chloroplasts were once bacteria that became part of eukaryotic cells.

What is evidence for endosymbiosis?

Own DNA, 70S ribosomes, double membrane, divide like bacteria.

What are the forms of fungi?

Yeasts (single cells) and molds (hyphae).

What do saprobes eat?

Dead things.

What do parasitic fungi eat?

Living hosts.

What are fungal spores for?

Reproduction and survival.

What are protozoa?

Single-celled eukaryotes with diverse lifestyles.

What are protozoa life cycle stages?

Trophozoite (active) and cyst (dormant).

How are protozoa classified?

By movement (cilia, flagella, pseudopods, nonmotile).

What are helminths?

Parasitic worms.

Types of helminths?

Roundworms, tapeworms, flukes.

What is metabolism?

All chemical reactions in a cell.

Catabolism vs anabolism?

Catabolism breaks; anabolism builds.

What does ATP do?

Provides energy.

What are the ways to make ATP?

Substrate-level, oxidative, photophosphorylation.

What are electron carriers?

NAD⁺, FAD, NADP⁺.

What are enzymes?

Proteins that speed reactions.

Constitutive vs regulated enzymes?

Always made vs made when needed.

What are the stages of aerobic respiration?

Glycolysis → intermediate step → Krebs → ETC.

Total ATP in prokaryotes?

~38.

Total ATP in eukaryotes?

~36.

What is the ETC?

Proteins that pump H⁺ to power ATP synthase.

Aerobic vs anaerobic vs fermentation?

Aerobic uses oxygen; anaerobic uses other molecules; fermentation makes little ATP.

How are lipids used for ATP?

Beta-oxidation → acetyl-CoA.

How are proteins used for ATP?

Deamination → enters Krebs.

What is amphibolism?

Pathways used for both building and breaking.

What is DNA made of?

Sugar, phosphate, bases (A T C G).

DNA direction?

5′ → 3′.

RNA differences?

Single-stranded, U instead of T.

Prokaryotic chromosome vs eukaryotic?

Prokaryotes: circular. Eukaryotes: linear and in nucleus.

What is DNA replication?

Copying DNA using enzymes like helicase, polymerase, ligase.

Central dogma?

DNA → RNA → protein.

What is transcription?

Making RNA from DNA.

What is translation?

Making protein from mRNA.

What are codons?

3-base mRNA groups for amino acids.

What is an operon?

Group of genes controlled together.

What is the lac operon for?

Breaking down lactose.

Genotype vs phenotype?

Genes vs expressed traits.

Vertical vs horizontal gene transfer?

Parent to offspring vs between microbes.

What is conjugation?

DNA transfer by pilus.

What is transformation?

Uptake of DNA from environment.

What is transduction?

Virus moves DNA between bacteria.

What is a mutation?

Change in DNA.

What is a SNP?

Single base change.

Missense vs nonsense vs frameshift?

Wrong amino acid vs stop codon vs shift reading frame.

What is recombinant DNA?

DNA combined from different sources.

What does PCR do?

Copies DNA.

What is CRISPR?

Gene-editing tool.

What are essential nutrients?

Needed for growth (C, H, N, O, P, S).

What are nutritional types?

Photoautotrophs, chemoheterotrophs, etc.

Passive vs active transport?

No energy vs uses energy.

What is osmosis?

Water movement.

What happens in hypotonic?

Water enters.

Hypertonic?

Water leaves.

What is a halophile?

Loves salt.

What temperatures do microbes prefer?

Psychrophile cold, mesophile moderate, thermophile hot.