Cells and Microorganisms - Vocabulary Flashcards

This set covers key concepts from the notes: cell theory, cell structure and organelles, membrane structure and transport, cell division, prokaryotic vs eukaryotic cells, energy and metabolism, photosynthesis and respiration, microorganisms in food production, and basic genetics and biotechnology.

MRSGREN

Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition—the seven characteristics used to describe living things.

Cell Theory

All living things are made of cells; the cell is the basic unit of life; new cells arise from preexisting cells; cells contain hereditary material (DNA/RNA) and carry out life processes.

Cell Membrane

A selectively permeable barrier that separates the cell from its surroundings and controls entry and exit of substances.

Phospholipid Bilayer

Two-layered membrane with hydrophilic heads facing outward and hydrophobic tails inward; forms the core structure of the cell membrane.

Cholesterol (in membranes)

A molecule that helps regulate membrane fluidity and stability, preventing tails from moving too freely at high temperatures.

Membrane Proteins

Proteins embedded in the membrane that assist with transport, signaling, and other functions.

Nucleus

Membrane-bound organelle in Eukaryotic cells that contains DNA and regulates cellular activities.

Nucleolus

Region within the nucleus where ribosomal RNA (rRNA) synthesis occurs and ribosomes begin to form.

Ribosome

Small structure (RNA-protein complex) where protein synthesis takes place; can be free or attached to rough ER.

Mitochondrion

Double-membrane organelle known as the powerhouse of the cell; site of aerobic respiration and ATP production.

Rough Endoplasmic Reticulum (RER)

Membrane network with ribosomes on its surface; synthesizes and transports proteins.

Smooth Endoplasmic Reticulum (SER)

Membrane network without ribosomes; involved in lipid and carbohydrate metabolism and detoxification.

Golgi Body (Golgi Apparatus)

Stack of membranes that modifies, packages, and exports proteins and lipids.

Lysosome

Small sac containing digestive enzymes used to break down waste materials and cellular debris.

Chloroplast

Organelle in plant cells where photosynthesis occurs; contains chlorophyll.

Vacoule

Membrane-bound storage sac; centralized in plant cells (large central vacuole) and smaller in animal cells.

Cell Wall

Rigid layer outside the cell membrane in plants (made of cellulose); provides support and protection.

Prokaryotic Cell

A primitive cell type without a nucleus or membrane-bound organelles; circular DNA; typically 1–10 μm.

Eukaryotic Cell

Cell type with a nucleus and membrane-bound organelles; linear chromosomes.

Capsule

External coating in some bacteria that aids adhesion.

Pili

Hair-like structures on some bacteria used for adhesion and genetic exchange.

Flagellum

Tail-like structure that enables movement and sensing the environment in some cells.

Nucleoid

Region in a prokaryotic cell where the circular chromosome is located (not enclosed by a membrane).

Chromosome

A length of DNA containing many genes; in eukaryotes, linear and inside the nucleus; in prokaryotes, usually circular.

Chromatid

A replicated chromosome still joined to its identical twin (sister chromatid) until separation during mitosis.

Interphase

Phase of the cell cycle where the cell grows, duplicates organelles, and copies DNA in preparation for division.

Mitosis

Nuclear division producing two genetically identical nuclei: Prophase, Metaphase, Anaphase, Telophase.

Cytokinesis

Division of the cytoplasm, resulting in two separate daughter cells after nuclear division.

Prophase

Chromosomes condense and become visible; spindle apparatus forms; nuclear envelope breaks down.

Metaphase

Chromosomes align along the cell equator with sister chromatids attached to spindle fibers.

Anaphase

Sister chromatids separate and are pulled to opposite poles.

Telophase

Nuclear membranes reform around two sets of chromosomes; cytoplasm divides.

Binary Fission

Asexual reproduction in prokaryotes where DNA is replicated, chromosome segregation occurs, and the cell divides into two identical cells.

Osmosis

Diffusion of water across a selectively permeable membrane from high to low water potential until equilibrium.

Diffusion

Movement of particles from an area of higher concentration to a lower concentration; passive process.

Facilitated Diffusion

Passive transport of larger or polar molecules via channel or carrier proteins down the concentration gradient.

Active Transport

Movement of substances against their concentration gradient, requiring energy (ATP) and carrier proteins.

Endocytosis

Bulk intake of materials into a cell by forming vesicles; requires energy.

Exocytosis

Bulk export of materials from a cell via vesicles fusing with the plasma membrane; requires energy.

Autotroph

Organism that makes its own organic matter from inorganic sources (e.g., photosynthesis or chemosynthesis).

Heterotroph

Organism that obtains organic matter by consuming other organisms.

Chemoautotroph

Autotroph that derives energy from inorganic chemical reactions (not light).

Photosynthesis

Process by which plants and some microorganisms convert light energy, water, and CO2 into glucose and O2; occurs in chloroplasts.

Equation (Photosynthesis)

6 CO2 + 6 H2O → C6H12O6 + 6 O2 (in plants and algae; simplified).

Cell Respiration (Aerobic)

Process that releases energy from glucose in the presence of oxygen; occurs in mitochondria and cytoplasm.

Equation (Respiration, Aerobic)

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP (36–38 ATP).

Fermentation

Anaerobic process that breaks down glucose to ethanol or lactic acid with limited ATP (2 ATP).

Yeast in Food Production

Yeast carries out fermentation to make bread, beer, and wine.

Penicillium

Genus of mold that produces penicillin; antibiotics discovered by Fleming; development by Florey.

Vitamin B12

Vitamin produced by archaea and bacteria; essential nutrient not made by plants/animals.

Vitamin K

Vitamin produced by gut bacteria (e.g., E. coli) in the large intestine.

Recombinant DNA

DNA formed by combining genetic material from different sources; used in insulin production, GM crops, vaccines, gene therapy; raises ethical considerations.

Transgenic Organism

Organism that contains genetic material from another species inserted into its genome.

Five Kingdoms

Monera (prokaryotes), Protista, Fungi, Plantae, Animalia (all eukaryotes).