Nucleic acids, cell structure, and bacterial cell walls (Vocabulary Flashcards)

A vocabulary-focused set of flashcards covering nucleic acids, cellular components, and bacterial cell wall features based on the provided notes.

Nucleic acids

Macromolecules made of a base, a sugar, and one or more phosphate groups; include DNA and RNA and energy-related adenosine phosphates.

Base

Nitrogen-containing ring attached to a sugar in nucleotides.

Sugar (in nucleotides)

Pentose sugar (deoxyribose in DNA, ribose in RNA) that bonds to bases and phosphates.

Phosphate

Phosphate group linking nucleotides via phosphodiester bonds.

Adenosine phosphates

Nucleotides containing adenosine; include ATP, ADP, and AMP; roles in energy transfer and signaling.

ATP (adenosine triphosphate)

Primary energy currency of the cell.

ADP (adenosine diphosphate)

Energy carrier formed when ATP loses a phosphate.

AMP (adenosine monophosphate)

Nucleotide with one phosphate; lower-energy state in energy transactions.

DNA

Deoxyribonucleic acid; stores genetic information and directs protein synthesis.

RNA

Ribonucleic acid; involved in transcription/translation and various roles in protein synthesis.

FAD

Flavin adenine dinucleotide; redox cofactor in metabolism.

NAD

Nicotinamide adenine dinucleotide; redox cofactor in metabolism.

Dehydration synthesis

Bond formation between molecules with loss of a water molecule.

Hydrolysis

Bond breaking by adding water; reverse of dehydration synthesis.

Prokaryotic cell

Bacteria; lacks a membrane-bound nucleus; single circular chromosome; cytoplasm with ribosomes; cell wall; may have flagella or plasmids.

Eukaryotic cell

Cells with a nucleus and membrane-bound organelles (e.g., plants, animals, fungi).

Cell membrane (plasma membrane)

Phospholipid bilayer with cholesterol and proteins; selective barrier of the cell.

Phospholipid bilayer

Two-layer arrangement of phospholipids forming the cell membrane interior.

Fluid mosaic model

Model of the cell membrane as a dynamic, fluid bilayer with proteins embedded in it.

Receptor

Membrane protein that binds signals to trigger cellular responses.

Channel (membrane protein)

Protein pore that allows passive diffusion of substances across the membrane.

Gated channel

Channel that opens or closes in response to stimuli.

Chloroplast

Plant organelle where photosynthesis occurs; contains chlorophyll.

Cell wall (plants)

Rigid layer outside the plasma membrane made of cellulose and other polysaccharides.

Gram-positive

Bacteria with thick peptidoglycan layer and teichoic acids; no outer membrane; stains purple.

Gram-negative

Bacteria with a thin peptidoglycan layer, outer membrane containing LPS; stains pink.

Peptidoglycan

Polymer of sugars and peptides forming the bacterial cell wall.

Teichoic acid

Acidic polymers in Gram-positive cell walls; contribute to wall properties.

Lipopolysaccharide (LPS)

Endotoxin component of the outer membrane of Gram-negative bacteria; triggers immune response.

Outer membrane

The outer lipid bilayer in Gram-negative bacteria containing LPS and proteins.

Glycocalyx

Sticky carbohydrate layer outside the cell wall; aids in protection and adhesion.

Capsule

Organized, tightly attached glycocalyx that protects against phagocytosis.

Slime layer

Unorganized, loosely attached glycocalyx that helps adherence to surfaces.

Flagellum

Long filamentous structure used for cellular locomotion; rotates.

Monotrichous

Single flagellum at one end of the cell.

Amphitrichous

Flagella at both ends of the cell.

Lophotrichous

Two or more flagella at one end (or at both ends) of the cell.

Peritrichous

Flagella distributed all around the cell surface.

Cilia

Short, hair-like projections that beat to move the cell or its surroundings.

Axial filaments

Bundles of endoflagella that wrap around the cell to produce corkscrew motion.

Pili (Fimbriae)

Hair-like structures for attachment; fimbriae help adherence to surfaces.

Sex pilus

Pilus used to transfer DNA between bacteria during conjugation.

Mycoplasma

Smallest known bacteria; lacks a cell wall; cell membrane rich in steroids.

Endospores

Dormant, dehydrated cells with thick walls that resist harsh environments and can germinate when favorable.

Terminal endospore

Endospore located at the end of the cell.

Subterminal endospore

Endospore located between the end and the middle of the cell.

Central endospore

Endospore located in the middle of the cell.

Protoplast

Gram-positive cell that has lost its cell wall.

Inclusions

Deposits inside the cell (lipids, sulfur, gases, polysaccharides).

Metachromatic inclusion

Inclusion containing phosphates; stains with metachromatic dyes.

Carboxysomes

Protein-based microcompartments containing enzymes for CO2 metabolism.

Osmotic pressure

Force required to prevent water movement across a semipermeable membrane.

Osmotic lysis

Cell rupture due to water influx in a hypotonic environment.

Diffusion

Movement of particles from high to low concentration until equilibrium.

Facilitated diffusion

Diffusion through a protein channel or carrier; no energy required.

Active transport

Movement against a concentration gradient; requires energy and a transport protein.

Endocytosis

Engulfing of external material by the cell; includes phagocytosis and pinocytosis.

Phagocytosis

Engulfment of solid particles by the cell.