Cell Biology Chapter 1.5

Study Notes

Cell Structure and Components

Nucleus acts as the cell's control center.
Nucleolus within the nucleus produces ribosomes.
Chromatin consists of thread-like structures that package DNA.
Chromosomes are compact DNA structures visible during cell division.
Centromere is a constricted region that holds sister chromatids together.
Chromatids are identical copies of a chromosome linked by a centromere.
Telomeres are protective ends of chromosomes.
Kinetochore serves as the attachment point for spindle fibers during cell division.

Cell Cycle

The cell cycle involves events leading to cell division and DNA duplication.
Interphase includes cell growth and DNA replication.
M Phase (Mitotic Phase) is the stage where actual cell division occurs.

Stages of Cell Cycle

Interphase: Period for cell growth and preparation for division.
G1 Phase: Routine metabolic processes and cell growth occur.
S Phase: DNA replication takes place.
G2 Phase: Further growth and preparation for mitosis happen.
M Phase: The cell divides into two daughter cells.

Mitosis Phases

Prophase: Chromosomes condense, nuclear envelope disintegrates, and mitotic spindle forms.
Metaphase: Chromosomes align at the metaphase plate.
Anaphase: Sister chromatids separate and move to opposite ends of the cell.
Telophase: Chromosomes decondense, nuclear envelope reforms, and mitotic spindle breaks down.

Cell Division

A process where one cell splits into two identical daughter cells.
Involves replication and distribution of genetic material.

Mitosis and Meiosis

Mitosis divides the nucleus into two nuclei maintaining chromosome number.
Meiosis produces four daughter cells, each with half the original chromosome number, essential for gamete formation.

Organelles Involved in Cell Division

Centrioles organize microtubules essential for cell division.
Microtubules facilitate intracellular transport and cell movement.

Cell Theory and History

All living organisms are made of cells.
Cells are the basic structural and organizational units.
All cells arise from pre-existing cells.
Key historical figures in cell theory include Hooke, Van Leeuwenhoek, Schleiden, Schwann, Virchow, Pasteur, Brown, and Flemming.

Types of Cells

Prokaryotic Cells: Simple structure without membrane-bound organelles, includes bacteria and archaea.
Eukaryotic Cells: More complex with membrane-bound organelles, includes animals, plants, fungi, and protists.

Cell Size and Organization

Cell size is constrained by surface area to volume ratio.
Cytoplasm is the fluid environment containing organelles.
Plasma membrane is the protective barrier of the cell.

Cell Modifications

Surface modifications include microvilli, cilia, and flagella for increased surface area or motility.
Internal modifications encompass:
- Rough Endoplasmic Reticulum: It has ribosomes for protein synthesis.
- Smooth Endoplasmic Reticulum: Involved in lipid synthesis and detoxification.
- Golgi Body: Processes and packages proteins.
- Mitochondria: The cell’s energy production center.
- Lysosomes: Digestive enzymes that break down waste.
- Peroxisomes: Contain enzymes for oxidation reactions.
- Vacuoles: Store substances and waste.
- Cytoskeleton: Provides structural support and facilitates movement.
- Centrioles: Play a role in organizing cell division processes.

Description

Explore the essential components of the cell cycle in this quiz. Test your understanding of cell structures such as the nucleus, nucleolus, and chromosomes, and their roles in cellular functions. Perfect for students studying cell biology at various levels.