Cell Structure and Function

Cell (Plasma)

Membrane

• Structure: The cell membrane is a structure that surrounds the cytoplasm and organelles of the cell.

  • Type of Structure: Made up of two layers known as the phospholipid bilayer.

• Job:

  • Regulates the movement of materials in and out of the cell, maintaining homeostasis.

Vacuoles

Structure

• Vacuoles:

  • Small and numerous in animal cells.

  • One large central vacuole found in plant cells.

Job

• Storage of water and other substances.

Golgi Apparatus (Golgi Complex, Golgi Bodies)

Structure

• a folded membrane.

Job

• Receives vesicles of protein from the Endoplasmic Reticulum (ER).

  • Vesicles are like small carts that transport proteins around the cell.

  • Processes, sorts, and ships proteins to where they are needed.

Lysosomes

Cell Type

• Found only in animal cells.

Structure

• Contain enzymes.

Job

• Lysosomes break down dead materials such as food, bacteria, and old parts of the cell (e.g., organelles).

• Capable of programmed cell death (apoptosis).

Ribosomes

Structure

• Composed of proteins and RNA.

• Located on the Rough ER and floating in the cytoplasm.

Job

• Responsible for making proteins.

Cell Wall

Structure

• This outer layer is present in:

  • Plant cells

  • Fungi cells

  • Bacterial cells

  • Some protists.

Job

• Supports, protects, and maintains the shape of cells.

• Not present in animal cells; only found in plant cells.

Cytoplasm

Structure

• A jelly-like substance primarily made up of water.

Job

• Holds everything in place within the cell.

Chloroplast

Cell Type

• Found only in plant cells.

Structure

• Found within eukaryotic cells including plants and some protists.

Job

• Utilize light energy to chemically convert water and carbon dioxide into simple sugars, storing chemical energy.

Mitochondria

Structure

• Composed of two parts:

  • Inner membrane

  • Matrix (the fluid part).

Job

• Site where cellular respiration occurs, breaking down food to release energy as ATP (Adenosine Triphosphate).

• Often referred to as the "powerhouse of the cell."

Cell (Plasma) ### Membrane - Structure: The cell membrane is a structure that surrounds the cytoplasm and organelles of the cell. - Type of Structure: Made up of two layers known as the phospholipid bilayer. - Job: - Regulates the movement of materials in and out of the cell, maintaining homeostasis.

## Vacuoles ### Structure - Vacuoles: - Small and numerous in animal cells. - One large central vacuole found in plant cells. ### Job - Storage of water and other substances.

## Golgi Apparatus (Golgi Complex, Golgi Bodies) ### Structure - a folded membrane. ### Job - Receives vesicles of protein from the Endoplasmic Reticulum (ER). - Vesicles are like small carts that transport proteins around the cell. - Processes, sorts, and ships proteins to where they are needed.

## Lysosomes ### Cell Type - Found only in animal cells. ### Structure - Contain enzymes. ### Job - Lysosomes break down dead materials such as food, bacteria, and old parts of the cell (e.g., organelles). - Capable of programmed cell death (apoptosis).

## Ribosomes ### Structure - Composed of proteins and RNA. - Located on the Rough ER and floating in the cytoplasm. ### Job - Responsible for making proteins.

## Cell Wall ### Structure - This outer layer is present in: - Plant cells - Fungi cells - Bacterial cells - Some protists. ### Job - Supports, protects, and maintains the shape of cells. - Not present in animal cells; only found in plant cells.

## Cytoplasm ### Structure - A jelly-like substance primarily made up of water. ### Job - Holds everything in place within the cell.

## Chloroplast ### Cell Type - Found only in plant cells. ### Structure - Found within eukaryotic cells including plants and some protists. ### Job - Utilize light energy to chemically convert water and carbon dioxide into simple sugars, storing chemical energy.

## Mitochondria ### Structure - Composed of two parts: - Inner membrane - Matrix (the fluid part). ### Job - Site where cellular respiration occurs, breaking down food to release energy as ATP (Adenosine Triphosphate). - Often referred to as the "powerhouse of the cell."

## Nucleus ### Structure - The largest organelle in a eukaryotic cell. - Contains the cell's genetic material (DNA) in the form of chromatin. - Enclosed by a double membrane called the nuclear envelope. ### Job - Controls all cell activities, including growth and metabolism. - Site where ribosome subunits are assembled (in the nucleolus).

## Centrioles ### Cell Type - Found only in animal cells. ### Structure - Paired, barrel-shaped structures. - Composed of microtubules. ### Job - Help organize cell division by forming spindle fibers (mitotic spindle).

• Aids in the physical separation of the cell during cell division.

• Also involved in the formation of cilia and flagella.