Cell Biology: Cell Membrane and Mitosis

Study Notes

Structure:
- Phospholipid bilayer with hydrophilic heads and hydrophobic tails
- Embedded proteins for transport, signaling, and cell-cell interactions
Functions:
- Regulates what enters and leaves the cell
- Maintains cell shape and provides mechanical support
- Acts as a barrier against external environment
- Involved in cell signaling and communication

Definition: Process of cell division that results in two daughter cells with identical genetic material
Stages:
1. Interphase: Cell grows, replicates DNA, and prepares for cell division
2. Prophase: Chromatin condenses, nuclear envelope breaks down, and centrioles move apart
3. Metaphase: Chromosomes align at the center of the cell
4. Anaphase: Sister chromatids separate and move to opposite poles
5. Telophase: Nuclear envelope reforms, and chromosomes uncoil
6. Cytokinesis: Cytoplasm divides, and cell splits into two daughter cells
Importance:
- Essential for growth, development, and tissue repair
- Allows for genetic diversity through crossing over during prophase

Definition: Process by which cells communicate with each other through signals
Types of Signaling:
- Autocrine signaling: Cells respond to signals they produce themselves
- Paracrine signaling: Cells respond to signals from nearby cells
- Endocrine signaling: Cells respond to signals from distant cells
Components:
- Signal molecules: Hormones, neurotransmitters, and growth factors
- Receptors: Proteins on the cell surface or within the cell that bind to signal molecules
- Signaling pathways: Series of molecular events that occur after signal reception
Functions:
- Regulates various cellular processes, such as growth, differentiation, and survival
- Enables cells to respond to changes in their environment

Phospholipid bilayer structure with hydrophilic heads and hydrophobic tails allows for selective permeability
Embedded proteins enable transport, signaling, and cell-cell interactions
Regulates movement of substances in and out of the cell
Maintains cell shape and provides mechanical support
Acts as a barrier against external environment
Involved in cell signaling and communication

Process of cell division resulting in two daughter cells with identical genetic material
Consists of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis stages
Interphase: cell growth, DNA replication, and preparation for cell division
Prophase: chromatin condensation, nuclear envelope breakdown, and centriole separation
Metaphase: chromosome alignment at the center of the cell
Anaphase: sister chromatid separation and movement to opposite poles
Telophase: nuclear envelope reformation and chromosome uncoiling
Cytokinesis: cytoplasmic division and cell splitting into two daughter cells
Essential for growth, development, and tissue repair
Allows for genetic diversity through crossing over during prophase

Process by which cells communicate with each other through signals
Autocrine signaling: cells respond to signals they produce themselves
Paracrine signaling: cells respond to signals from nearby cells
Endocrine signaling: cells respond to signals from distant cells
Signal molecules: hormones, neurotransmitters, and growth factors
Receptors: proteins on the cell surface or within the cell that bind to signal molecules
Signaling pathways: series of molecular events that occur after signal reception
Regulates various cellular processes, such as growth, differentiation, and survival
Enables cells to respond to changes in their environment