Cell Biology Basics

Study Notes

Also known as the plasma membrane
A thin, semi-permeable layer that surrounds the cell
Composed of a phospholipid bilayer with embedded proteins
Functions:
- Regulates what enters and leaves the cell
- Maintains cell shape
- Provides mechanical support
- Acts as a barrier against external substances

Process by which a cell becomes two daughter cells
Types:
- Mitosis: occurs in somatic cells, resulting in two identical daughter cells
- Meiosis: occurs in reproductive cells, resulting in four non-identical daughter cells
Stages:
- Interphase: cell grows and prepares for division
- Prophase: chromatin condenses into visible chromosomes
- Metaphase: chromosomes line up at the center of the cell
- Anaphase: sister chromatids separate
- Telophase: nuclear envelope reforms
- Cytokinesis: cytoplasm divides and cells split

The jelly-like substance inside the cell membrane
Composed of:
- Water
- Salts
- Sugars
- Proteins
- Organelles
Functions:
- Supports metabolic reactions
- Provides mechanical support
- Helps maintain cell shape
- Acts as a medium for chemical reactions

Often referred to as the "powerhouses" of the cell
Functions:
- Generates energy for the cell through cellular respiration
- Converts glucose into ATP (adenosine triphosphate)
- Regulates cell growth and division
Structure:
- Outer membrane
- Inner membrane with folds (cristae) to increase surface area
- Mitochondrial matrix where energy production occurs

The cell membrane is a thin, semi-permeable layer surrounding the cell, composed of a phospholipid bilayer with embedded proteins.
It regulates what enters and leaves the cell, maintains cell shape, provides mechanical support, and acts as a barrier against external substances.

Cell division is the process by which a cell becomes two daughter cells, occurring through mitosis in somatic cells and meiosis in reproductive cells.
Mitosis results in two identical daughter cells, while meiosis results in four non-identical daughter cells.
The stages of cell division include:
- Interphase: cell growth and preparation for division
- Prophase: chromatin condenses into visible chromosomes
- Metaphase: chromosomes line up at the center of the cell
- Anaphase: sister chromatids separate
- Telophase: nuclear envelope reforms
- Cytokinesis: cytoplasm divides and cells split

Cytoplasm is the jelly-like substance inside the cell membrane, composed of water, salts, sugars, proteins, and organelles.
It supports metabolic reactions, provides mechanical support, helps maintain cell shape, and acts as a medium for chemical reactions.

Mitochondria are often referred to as the "powerhouses" of the cell, generating energy for the cell through cellular respiration.
They convert glucose into ATP (adenosine triphosphate) and regulate cell growth and division.
The structure of mitochondria includes an outer membrane, inner membrane with folds (cristae) to increase surface area, and a mitochondrial matrix where energy production occurs.

The cell membrane, also known as the plasma membrane, is a semi-permeable membrane that surrounds the cell.
The membrane is composed of a phospholipid bilayer with hydrophilic heads and hydrophobic tails.
Embedded proteins, both integral and peripheral, are also present in the membrane.
The cell membrane regulates what enters and leaves the cell, provides structural support, and maintains cell shape, acting as a barrier against external substances.

Cytoplasm is a jelly-like substance inside the cell membrane, composed of up to 90% water, salts, sugars, amino acids, and organelles like mitochondria and ribosomes.
Cytoplasm provides a medium for metabolic reactions, supports and suspends organelles, maintains cell shape, and plays a role in cell signaling and communication.

Mitochondria are often referred to as the "powerhouses" of the cell, found in the cytoplasm.
The primary function of mitochondria is to generate energy for the cell through cellular respiration, converting glucose into ATP (adenosine triphosphate).
Mitochondria have an outer membrane, an inner membrane (folded into cristae, increasing surface area), and a matrix where citric acid cycle and fatty acid oxidation occur.
Mitochondria regulate cellular metabolism and are essential for cellular energy production.