Cell Structure and Organelles (Video Notes)

Vocabulary flashcards covering cell walls, organelles, and related structures from Page 1-2 notes.

Cell Wall

Rigid external layer providing support and preventing excess water uptake; bacteria have peptidoglycan, plants have cellulose, fungi have chitin. (Present in plant, fungi, and bacteria cells)

Peptidoglycan

Polymer forming the bacterial cell wall; provides structural strength and shape. (Present in bacterial cells)

Cellulose

Polysaccharide forming plant cell walls; provides rigidity and support. (Present in plant cells)

Chitin

Polysaccharide forming fungal cell walls; provides rigidity and protection. (Present in fungal cells)

Centrosome

Microtubule organizing center; forms spindle fibers during cell division and helps organize the cytoskeleton. (Present in animal cells)

Chloroplast

Double-membrane organelle with internal stacks of membranous discs (thylakoids); site of photosynthesis and storage of manufactured organic molecules. (Present in plant cells)

Thylakoid

Flattened membrane-bound sacs inside chloroplasts where the light-dependent reactions of photosynthesis occur. (Present in plant cells)

Cristae

Foldings of the inner mitochondrial membrane that increase surface area for ATP production. (Present in eukaryotic cells)

Cytoskeleton

Network of protein filaments providing internal structure and mediating intracellular transport. (Present in eukaryotic and prokaryotic cells)

Cytosol

Fluid portion of the cytoplasm; mostly water with enzymes; holds organelles in place and participates in metabolism. (Present in eukaryotic and prokaryotic cells)

Cytoplasm

Internal content of the cell excluding the nucleus; includes cytosol and organelles. (Present in eukaryotic and prokaryotic cells)

Rough Endoplasmic Reticulum

Membrane network studded with ribosomes; site of protein synthesis for export. (Present in eukaryotic cells)

Smooth Endoplasmic Reticulum

Membrane network lacking ribosomes; synthesizes lipids and metabolizes toxins. (Present in eukaryotic cells)

Golgi apparatus

Stack of flattened membranes that modifies, sorts, and packages proteins for secretion or delivery to other organelles. (Present in eukaryotic cells)

Lysosome

Membranous sacs containing hydrolytic enzymes; digest macromolecules. (Present in eukaryotic cells)

Mitochondrion

Double-membrane organelle with cristae; site of aerobic respiration and ATP production. (Present in eukaryotic cells)

Cristae

Foldings of the inner mitochondrial membrane increasing surface area for respiration (note: often discussed with mitochondrion). (Present in eukaryotic cells)

Nucleoid

Region in prokaryotes where the bacterial chromosome is concentrated. (Present in bacterial cells)

Nucleolus

Dense region inside the nucleus; site of ribosomal RNA synthesis and ribosome assembly. (Present in eukaryotic cells)

Nucleus

Double-membrane organelle containing the cell’s genetic material; site of transcription and ribosome assembly. (Present in eukaryotic cells)

Nuclear Envelope

Double membrane surrounding the nucleus with nuclear pores; controls movement of substances between nucleus and cytoplasm. (Present in eukaryotic cells)

Chromatin

DNA-protein complex in the nucleus; condenses into chromosomes during cell division. (Present in eukaryotic cells)

Peroxisome

Membranous organelle with enzymes for oxidative metabolism; breaks down hydrogen peroxide and fatty acids. (Present in eukaryotic cells)

Plasma membrane

Phospholipid bilayer with embedded proteins; semi-permeable barrier regulating movement of substances in and out of the cell. (Present in eukaryotic and prokaryotic cells)

Ribosome (70S)

Ribosomal subunits typical of prokaryotes; site of polypeptide synthesis. (Present in prokaryotic cells)

Ribosome (80S)

Ribosomes in eukaryotes (cytoplasm and rough ER); site of polypeptide synthesis. (Present in eukaryotic cells)

Vacuole

Membrane-bound vesicle for storage; plants have a large central vacuole that maintains turgor; animals/fungi have smaller or varied vacuoles. (Present in plant and fungal cells)

Tonoplast

Membrane surrounding the plant vacuole; regulates movement of substances between cytosol and vacuole. (Present in plant cells)

Vesicle

Membranous sac that transports materials within the cell. (Present in eukaryotic cells)