Chapter 5 Study Guide: Cell Structure, Function & Microorganisms

Vocabulary flashcards covering core cellular organelles, comparative cellular organization, microorganisms, locomotive structures, and diagnostic slide identification criteria.

Nucleus

The membrane-bound organelle that houses genetic material (DNA) and directs cellular activities through gene expression.

Nucleolus

A dense region within the nucleus responsible for ribosomal RNA (rRNA) synthesis and ribosome assembly.

Plasma Membrane (Cell Membrane)

A selectively permeable phospholipid bilayer enclosing the cytoplasm, regulating the passage of substances into and out of all cells.

Cell Wall

A rigid exterior layer surrounding the cell membrane that provides structural support, protection, and shape (composed of cellulose in plants, chitin in fungi, and peptidoglycan in bacteria).

Cytoplasm / Cytosol

The fluid-like cellular material bounded by the plasma membrane containing suspended organelles, dissolved ions, and nutrients.

Mitochondria

Double-membraned organelles known as the "powerhouses of the cell," producing ATP through cellular respiration.

Chloroplasts

Double-membraned organelles found in plant and algal cells containing chlorophyll; site of photosynthesis.

Central Vacuole

A large membrane-bound sac in plant cells storing water, nutrients, and waste while maintaining cell turgor pressure.

Ribosomes

Non-membrane-bound complexes of RNA and proteins that synthesize polypeptides during translation.

Rough ER

Part of the endoplasmic reticulum studded with ribosomes; synthesizes and processes membrane/secretory proteins.

Smooth ER

Part of the endoplasmic reticulum lacking ribosomes; synthesizes lipids, metabolizes carbs, and detoxifies chemicals.

Golgi Apparatus

A stack of flattened membranous sacs that modifies, sorts, and packages proteins/lipids into vesicles for transport.

Lysosomes

Membrane-bound vesicles packed with hydrolytic digestive enzymes that break down macromolecules, old organelles, and foreign substances.

Unicellular

Solitary, independent single-celled organisms carrying out all life functions independently (e.g., Amoeba, Paramecium).

Colonial

Clusters of individual cells living cooperatively without specialized tissue differentiation (e.g., Spirogyra filaments).

Multicellular

Complex organisms composed of specialized cells organized into tissues, organs, and organ systems.

Amoeba

A unicellular heterotrophic protist that moves and feeds via cytoplasmic streaming. They move via Pseudopods and have a nucleus

Pseudopodia

Temporary cytoplasmic extensions ("False Feet") help the amoeba move and engulf food via phagocytosis.

Contractile Vacuole

Organelle that pumps excess water out to maintain osmotic balance.

Paramecium

A unicellular, ciliated heterotrophic protist possessing an oral groove and a dual-nucleus system (micronucleus and macronucleus) for reproduction and metabolic regulation. It moves by CIilia and has a nucleus

Cilia

Numerous short, hair-like projections cover the cell surface and beat rhythmically to move and take in food. They help the Paramecium move

Euglena

A unicellular protist capable of both autotrophy (photosynthesis) and heterotrophy. They move via Flagellum and have a Nucleus

Flagellum

A long, whip-like appendage used to propel Euglena through liquid environments.

Eyespot (Stigma)

A colored photoreceptive structure that senses light direction and guides phototaxis toward light sources.

Spirogyra

A photosynthetic, filamentous green algae (colonial) easily recognized under a microscope.They cannot move, but they have a Nucleus

Pyrenoids

Small dense structures within chloroplasts involved in starch synthesis and storage.

Ribbon-like Spiral Chloroplasts

Distinctive green helical chloroplast bands extending along each cylindrical cell.

Plant Cells

Have cell wall and a cell membrane via cellulose, chloroplasts, and a central vacuole; usually rectangular/fixed shape, and do not have centrioles

Animal Cells

Lack cell wall, chloroplasts, and central vacuole, contain small lysosomes/centrioles, usually flexible/irregular shape, and only has a cell membrane

Fungal Cells

Have a cell wall and cell membrane made of chitin

Bacterial cells

Have a cell wall and membrane made of peptidoglycan