Cell Structure and Function

Cell Structure

• Plasma Membrane: Semi-permeable membrane that separates the cell from its environment
• Cytoplasm: Jelly-like substance inside the cell where metabolic processes take place
• 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): Network of membranous tubules and cisternae involved in protein synthesis and transport
• Ribosomes: Small organelles found throughout the cytoplasm where protein synthesis occurs
• Lysosomes: Membrane-bound sacs containing digestive enzymes that break down and recycle cellular waste
• Golgi Apparatus: Complex of flattened sacs and tubules involved in protein modification and transport

Cell Functions

• Metabolism: Chemical reactions that occur within the cell to maintain life
• Growth and Development: Cells grow, divide, and differentiate to form tissues and organs
• Response to Stimuli: Cells respond to changes in their environment through signaling pathways
• Reproduction: Cells divide to produce new cells through mitosis or meiosis
• Waste Management: Cells remove waste products through exocytosis and autophagy

Cell Types

• Prokaryotic Cells: Lack a true nucleus, found in bacteria and archaea
• Eukaryotic Cells: Possess a true nucleus, found in plants, animals, fungi, and protists
• Stem Cells: Undifferentiated cells that can differentiate into specialized cells

Cell Cycle

• Interphase: Cell grows, replicates its DNA, and prepares for cell division
• Mitosis: Process of cell division that results in two daughter cells with identical DNA
• Cytokinesis: Division of the cytoplasm to form two daughter cells

Cell Structure and Function

• Cell membrane: Separates the cell from its environment, semi-permeable, and allows selective passage of molecules.
• Cytoplasm: Jelly-like substance inside the cell where metabolic processes, such as glycolysis, take place; maintains cell shape and provides mechanical support.
• Nucleus: Control center of the cell, stores DNA, and regulates gene expression.

Cellular Organelles

• Mitochondria: Generates energy for the cell through cellular respiration, converting glucose into ATP.
• Endoplasmic Reticulum (ER): Involved in protein synthesis, lipid synthesis, and detoxification; has two types: rough ER (with ribosomes) and smooth ER (without ribosomes).
• Ribosomes: Sites of protein synthesis, found throughout the cytoplasm, and composed of rRNA and proteins.
• Lysosomes:Membrane-bound sacs containing digestive enzymes, responsible for cellular digestion and recycling.
• Golgi Apparatus: Modifies and transports proteins and lipids, forming vesicles for secretion or lysosomal degradation.

Cellular Activities

• Metabolic Pathways: Chemical reactions that occur within the cell to maintain life, including glycolysis, citric acid cycle, and electron transport chain.
• Cell Growth and Development: Involves cell growth, division, and differentiation, leading to tissue and organ formation.
• Cell Signaling: Cells respond to stimuli through signaling pathways, which involve receptors, signal transduction, and effectors.
• Cell Division: Involves mitosis (division of the nucleus) and cytokinesis (division of the cytoplasm).
• Waste Management: Cells remove waste products through exocytosis (removing excess substances) and autophagy (recycling cellular components).

Cell Types and Cell Cycle

• Prokaryotic Cells: Lack a true nucleus, have a single circular chromosome, and are found in bacteria and archaea.
• Eukaryotic Cells: Possess a true nucleus, have linear chromosomes, and are found in plants, animals, fungi, and protists.
• Stem Cells: Undifferentiated cells that can differentiate into specialized cells, maintaining tissue homeostasis.
• Interphase: Cell grows, replicates its DNA, and prepares for cell division.
• Mitosis: Consists of prophase, metaphase, anaphase, and telophase, resulting in two daughter cells with identical DNA.

Cell Structure

• The plasma membrane is semi-permeable, regulating what enters and leaves the cell.
• Cytoplasm is a jelly-like substance inside the cell membrane where metabolic processes occur.
• The nucleus is the control center of the cell, containing most of the cell's genetic material (DNA).
• Mitochondria produce energy for the cell through cellular respiration.
• The 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, breaking down and recycling cellular waste and foreign substances.
• The Golgi Apparatus is a complex of flattened sacs and tubules involved in protein modification, sorting, and packaging.

Cell Types

• Prokaryotic cells lack a true nucleus and membrane-bound organelles, and are typically found in bacteria.
• Eukaryotic cells possess a true nucleus and membrane-bound organelles, and are typically found in plants, animals, and fungi.

Cellular Processes

• Metabolism is the conversion of energy and nutrients to sustain life.
• Cell division involves the growth, replication, and division of cells through mitosis and meiosis.
• Photosynthesis is the process by which plants and some other organisms convert light energy into chemical energy.

Cell Membrane Functions

• Passive transport is the movement of molecules across the cell membrane without energy input, including diffusion and osmosis.
• Active transport is the movement of molecules across the cell membrane requiring energy input, including pumps and transport proteins.
• Cell signaling is the communication between cells through signaling molecules and receptors.