Cell Biology: Understanding Cell Components and Their Functions

What is a Plasma Membrane, and Do All Cells Have One?

The plasma membrane encloses the cytoplasm and the cell's genetic material. It regulates what enters and exits the cell. Yes, all cells have a plasma membrane.

What Are the Two Central Tenets of Cell Theory?

• All organisms are composed of cells.
• Cells come only from preexisting cells.

What Are the Two Main Types of Cells?

• Prokaryotic cells lack a membrane-bound nucleus.
• Eukaryotic cells have a nucleus that houses DNA.

Where Do Prokaryotic Cells Store Their Genetic Material?

In the nucleoid.

What Domains Do Prokaryotic Cells Belong To?

Archaea and Bacteria.

What Are Three Characteristics of Prokaryotic Cells?

• They are much smaller and simpler than eukaryotic cells.
• They reproduce very quickly and effectively due to their small size.

Cell Components and Their Functions:

Cytoplasm
The material between the cell membrane and the nucleus.

Nucleus
Stores DNA and controls most of the cell's processes.

Ribosome
Makes proteins using coded instructions from the nucleus.

Cytoskeleton
Helps a cell keep its shape.

Cell Wall
Supports and protects the cell.

Cell Membrane
Serves as the cell's boundary from its environment and regulates which materials enter and leave the cell.

Nucleolus
A small, dense region in the nucleus where the assembly of proteins begins.

Rough Endoplasmic Reticulum
An internal membrane system with ribosomes on its surface where proteins are assembled.

Smooth Endoplasmic Reticulum
An internal membrane system where lipids are assembled.

Golgi Apparatus
Modifies, sorts, and packages protein and other materials.

Mitochondria
Converts food to ATP. Where cellular respiration takes place.

Chloroplast
Captures energy from sunlight and converts it into chemical energy.

Centrioles
Found in animal cells. Organizes the chromosomes during cell division.

Lysosomes
Contains enzymes that break down lipids, carbohydrates, and proteins.

Vacuole
Saclike structure that stores materials.

Nuclear Envelope
A double membrane that surrounds the nucleus.

Chromatin
A granular material made up of DNA bound to protein.

Chromosome
Threadlike structure that contains genetic information.

Cilia
Short, hairlike projections used for feeding and movement.

Flagella
Long, whip-like structure used for movement.