Cell Structure and Organelles

Study Notes

Plasma membrane: semi-permeable membrane that surrounds the cell, composed of phospholipids, proteins, and cholesterol
Cytoplasm: jelly-like substance inside the cell membrane, composed of water, salts, sugars, and organelles
Nucleus: membrane-bound organelle that contains genetic material (DNA)
Mitochondria: organelles responsible for generating energy for the cell through cellular respiration
Endoplasmic reticulum (ER): network of membranous tubules and cisternae involved in protein synthesis, transport, and storage
Ribosomes: small organelles found throughout the cytoplasm, responsible for protein synthesis
Lysosomes: membrane-bound organelles that contain digestive enzymes, responsible for cellular digestion and recycling
Golgi apparatus: complex of flattened sacs and tubules involved in protein modification, sorting, and transport

Cellular respiration: process by which cells generate energy from glucose, involving glycolysis, pyruvate oxidation, and oxidative phosphorylation
Photosynthesis: process by which cells produce glucose and oxygen from light energy, water, and carbon dioxide
Protein synthesis: process by which cells create proteins from amino acids, involving transcription and translation
Cell signaling: process by which cells communicate with each other through signaling molecules and pathways
Cell division: process by which cells replicate and divide, involving mitosis and cytokinesis
Apoptosis: process of programmed cell death, important for development, growth, and tissue homeostasis

Passive transport: movement of molecules across the cell membrane without energy input, including diffusion, osmosis, and facilitated diffusion
Active transport: movement of molecules across the cell membrane using energy, including carrier proteins and pumps
Endocytosis: process by which cells take in molecules and particles from outside the cell, involving vesicle formation and fusion
Exocytosis: process by which cells release molecules and particles outside the cell, involving vesicle fusion with the plasma membrane

Interphase: stage of the cell cycle where the cell grows, replicates its DNA, and prepares for cell division
Mitosis: stage of the cell cycle where the replicated DNA is divided equally between two daughter cells
Cytokinesis: stage of the cell cycle where the cytoplasm divides and the cell splits into two daughter cells
Meiosis: specialized cell division that occurs in reproductive cells, resulting in four haploid daughter cells

Plasma membrane is semi-permeable, surrounding the cell, and composed of phospholipids, proteins, and cholesterol
Cytoplasm is a jelly-like substance inside the cell membrane, consisting of water, salts, sugars, and organelles
Nucleus contains genetic material (DNA) and is a membrane-bound organelle
Mitochondria generate energy for the cell through cellular respiration
Endoplasmic Reticulum (ER) is a network of membranous tubules and cisternae involved in protein synthesis, transport, and storage
Ribosomes are small organelles found throughout the cytoplasm, responsible for protein synthesis
Lysosomes contain digestive enzymes, responsible for cellular digestion and recycling
Golgi apparatus is a complex of flattened sacs and tubules involved in protein modification, sorting, and transport

Cellular respiration generates energy from glucose through glycolysis, pyruvate oxidation, and oxidative phosphorylation
Photosynthesis produces glucose and oxygen from light energy, water, and carbon dioxide
Protein synthesis creates proteins from amino acids through transcription and translation
Cell signaling allows cells to communicate with each other through signaling molecules and pathways
Cell division involves the replication and division of cells through mitosis and cytokinesis
Apoptosis is programmed cell death, important for development, growth, and tissue homeostasis

Passive transport moves molecules across the cell membrane without energy input, including diffusion, osmosis, and facilitated diffusion
Active transport moves molecules across the cell membrane using energy, including carrier proteins and pumps
Endocytosis takes in molecules and particles from outside the cell, involving vesicle formation and fusion
Exocytosis releases molecules and particles outside the cell, involving vesicle fusion with the plasma membrane

Interphase is the stage where the cell grows, replicates its DNA, and prepares for cell division
Mitosis divides the replicated DNA equally between two daughter cells
Cytokinesis divides the cytoplasm and splits the cell into two daughter cells
Meiosis is a specialized cell division that occurs in reproductive cells, resulting in four haploid daughter cells