Cell Structure and Function

Plasma membrane: semi-permeable membrane that separates the cell from its environment
Cytoplasm: jelly-like substance inside the cell where metabolic processes occur
Cytoskeleton: network of filaments that provides structural support and shape to the cell
Nucleus: control center of the cell where DNA is stored
Mitochondria: organelles responsible for generating energy for the cell through cellular respiration
Endoplasmic reticulum (ER): organelle involved in protein synthesis, transport, and storage
Ribosomes: site of protein synthesis
Lysosomes: membrane-bound sacs that contain digestive enzymes
Golgi apparatus: organelle involved in protein modification and transport

Selective permeability: allows certain substances to pass through while keeping others out
Passive transport: movement of molecules from high to low concentration without energy input (diffusion, osmosis)
Active transport: movement of molecules from low to high concentration with energy input (carrier proteins, pumps)

Mitosis: process of cell division that results in two daughter cells with the same number of chromosomes as the parent cell
- Interphase: cell grows, replicates DNA, and prepares for cell division
- Prophase: chromosomes condense, nuclear envelope breaks down, and spindle fibers form
- Metaphase: chromosomes line up at the center of the cell
- Anaphase: sister chromatids separate and move to opposite poles
- Telophase: nuclear envelope reforms, and chromosomes uncoil
Meiosis: process of cell division that results in four daughter cells with half the number of chromosomes as the parent cell (gamete formation)

Centrioles: involved in the formation of cilia, flagella, and spindle fibers
Chloroplasts: organelles found in plant cells responsible for photosynthesis
Peroxisomes: organelles involved in the breakdown of fatty acids and amino acids
Cilia and flagella: structures involved in cell motility and sensing the environment

Plasma membrane acts as a barrier, regulating the entry and exit of substances.
Cytoplasm contains organelles and is the site for metabolic reactions.
Cytoskeleton provides mechanical strength and maintains cell shape.
Nucleus houses genetic material (DNA) and controls cellular activities.
Mitochondria produce ATP through cellular respiration, known as the powerhouse of the cell.
Endoplasmic reticulum (ER) consists of rough (ribosome-studded) and smooth (lipid synthesis) regions, vital for protein processing.
Ribosomes, either free-floating or attached to the ER, are the sites for protein synthesis.
Lysosomes digest unwanted materials and cellular debris, containing hydrolytic enzymes.
Golgi apparatus modifies, sorts, and packages proteins for secretion or delivery within the cell.

Selective permeability is essential for maintaining homeostasis by allowing specific ions and molecules to enter or exit.
Passive transport requires no energy; includes diffusion (movement of molecules from high to low concentration) and osmosis (water movement).
Active transport requires energy (ATP) to move substances against their concentration gradient, involving mechanisms like carrier proteins.

Mitosis results in two genetically identical daughter cells, preserving the original chromosome number.
- Interphase: cell prepares for division by growing and duplicating DNA.
- Prophase: chromosomes become visible as they condense, and the nuclear envelope disassembles.
- Metaphase: chromosomes align at the cell equator (metaphase plate).
- Anaphase: sister chromatids are pulled apart to opposite cell poles.
- Telophase: chromosomes decondense, and new nuclear envelopes form around each set of chromosomes.
Meiosis leads to gamete formation, producing four daughter cells with half the chromosome number (haploid).

Centrioles play a key role in cell division and the formation of motility structures like cilia and flagella.
Chloroplasts are unique to plant cells, facilitating photosynthesis by converting light energy into chemical energy (glucose).
Peroxisomes are crucial for lipid metabolism and detoxification processes, breaking down fatty acids and amino acids.
Cilia and flagella allow cells to move and respond to environmental stimuli, enhancing their motility and sensory capabilities.