Ultra cell structure - Vocabulary flashcards

A set of vocabulary-flavored flashcards covering key organelles, structures, and concepts from the Ultra cell structure notes.

Magnification

The ratio of image size to actual size; how many times larger an image is compared with the specimen.

Resolution

The ability to distinguish two points as separate; the minimum distance at which two points can be seen as distinct.

Light microscope

A microscope that uses light to form an image; uses glass lenses and typically has lower resolution than electron microscopes.

Electron microscope

A microscope that uses electron beams for imaging; provides higher resolution and magnification than light microscopes.

Ribosomes

Non-membrane-bound particles where protein synthesis occurs; 80S in eukaryotes and 70S in mitochondria/chloroplasts.

Rough endoplasmic reticulum (RER)

Endoplasmic reticulum with attached ribosomes; site of protein synthesis and initial modification of polypeptides.

Smooth endoplasmic reticulum (SER)

Endoplasmic reticulum lacking ribosomes; involved in lipid synthesis and detoxification.

Golgi body

Organelle that modifies, sorts, and packages proteins; produces secretory vesicles and lysosomes.

Vesicles

Small membrane-bound sacs used for transport of materials within the cell or for secretion.

Lysosomes

Membrane-bound organelles containing hydrolytic enzymes for digestion of worn-out organelles and pathogens.

Mitochondrion

Double-membrane organelle; site of aerobic respiration; produces ATP; contains cristae, matrix, and its own 70S ribosomes and DNA.

Cristae

Folded inner membrane of mitochondria that increases surface area for ATP synthesis.

Chloroplast

Plant organelle with double membrane; site of photosynthesis; contains thylakoids, granum, stroma, loop of DNA, and 70S ribosomes.

Thylakoid

Flattened membrane sacs inside chloroplasts where light-dependent reactions occur.

Granum (grana)

Stacks of thylakoids within a chloroplast.

Stroma

Fluid matrix inside chloroplasts surrounding the thylakoids where the Calvin cycle occurs.

Amyloplast

Plastid that stores starch (amylose and amylopectin) in plant tissues.

Large vacuole

A large, single membrane-bound organelle in plants filled with cell sap; maintains turgor and stores substances.

Tonoplast

The membrane surrounding a plant cell’s large vacuole.

Nucleus

Double-membrane-bound organelle that stores DNA; contains chromatin and nucleolus; surrounded by a nuclear envelope with pores.

Nucleolus

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

Nuclear envelope

Double membrane surrounding the nucleus; perforated by nuclear pores and continuous with rough ER.

Chromatin

Complex of DNA and histone proteins; condenses to form chromosomes during cell division.

Endoplasmic reticulum (ER)

Network of membranes; cisternae form flattened sacs; rough ER has ribosomes; smooth ER lacks ribosomes.

Golgi apparatus faces

The forming (cis) face receives vesicles from ER; the maturing (trans) face releases processed vesicles.

Mitosis and ribosome types

70S ribosomes in mitochondria/chloroplasts; 80S ribosomes in the cytoplasm and on rough ER.

Prokaryotes vs Eukaryotes

Prokaryotes lack membrane-bound organelles; Eukaryotes have them (nucleus, mitochondria, chloroplasts, etc.).

Cell wall composition (plants, fungi, bacteria)

Plants: cellulose; fungi: chitin; bacteria: peptidoglycan (murein). Historically: differences in rigidity and composition.

Plasmodesmata

Channels through cell walls of adjacent plant cells enabling transport and communication.

Middle lamella

Layer rich in pectin between plant cell walls that glues adjacent cells together.