Cell Biology Basics

Also known as the plasma membrane
Semi-permeable phospholipid bilayer that surrounds the cell
Functions:
- Regulates what enters and leaves the cell
- Maintains cell shape
- Provides mechanical support
- Acts as a barrier against external environment
Components:
- Phospholipids (phosphate head, fatty acid tail)
- Proteins (integral, peripheral)
- Cholesterol
- Carbohydrates

Process by which a cell divides into two daughter cells
Types:
1. Mitosis: somatic cell division (results in two identical daughter cells)
2. Meiosis: reproductive cell division (results in four non-identical daughter cells)
Phases:
1. Interphase: cell growth and preparation for division
2. Prophase: chromatin condenses, nuclear envelope breaks down
3. Metaphase: chromosomes align at the center of the cell
4. Anaphase: sister chromatids separate
5. Telophase: nuclear envelope reforms, chromatin uncoils
6. Cytokinesis: cytoplasm divides, and the cell splits

Process by which cells generate energy from glucose
Stages:
1. Glycolysis: glucose is broken down into pyruvate (produces ATP and NADH)
2. Citric Acid Cycle (Krebs Cycle): pyruvate is converted into ATP, NADH, and FADH2
3. Electron Transport Chain: energy from NADH and FADH2 is used to generate ATP
4. Oxidative Phosphorylation: ATP is generated through the electron transport chain
Types:
1. Aerobic Respiration: occurs in the presence of oxygen
2. Anaerobic Respiration: occurs in the absence of oxygen

Process by which cells communicate with each other
Types:
1. Direct Cell-Cell Contact: cells communicate through direct physical contact
2. Paracrine Signaling: cells communicate through signaling molecules (hormones, growth factors)
3. Endocrine Signaling: cells communicate through signaling molecules (hormones) released into the bloodstream
4. Synaptic Signaling: cells communicate through electrical and chemical signals (neurons)
Components:
1. Receptors: proteins that bind to signaling molecules
2. Signaling Molecules: molecules that transmit signals between cells
3. Signal Transduction Pathways: series of molecular interactions that transmit signals

Semi-permeable phospholipid bilayer that surrounds the cell and regulates what enters and leaves the cell
Maintains cell shape and provides mechanical support
Acts as a barrier against external environment
Composed of phospholipids, proteins (integral and peripheral), cholesterol, and carbohydrates

Process by which a cell divides into two daughter cells
Mitosis is somatic cell division, resulting in two identical daughter cells
Meiosis is reproductive cell division, resulting in four non-identical daughter cells
Interphase is the cell growth and preparation stage
Prophase involves chromatin condensation and nuclear envelope breakdown
Metaphase involves chromosome alignment at the cell center
Anaphase involves sister chromatid separation
Telophase involves nuclear envelope reformation and chromatin uncoiling
Cytokinesis involves cytoplasm division and cell splitting

Process by which cells communicate with each other
Direct Cell-Cell Contact involves communication through direct physical contact
Paracrine Signaling involves communication through signaling molecules (hormones, growth factors)
Endocrine Signaling involves communication through signaling molecules (hormones) released into the bloodstream
Synaptic Signaling involves communication through electrical and chemical signals (neurons)
Receptors are proteins that bind to signaling molecules
Signaling Molecules transmit signals between cells
Signal Transduction Pathways involve a series of molecular interactions that transmit signals