Chapter 7.2: Cell Structure

Endoplasmic Reticulum

Liquid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell.

Centriole

Located near the nucleus and help organize cell division. These aren't found in plant cells.

Lysosome

Small organelles filled with enzymes, which help break down lipids, carbohydrates, and proteins into small molecules that can be used for the rest of the cell. They also break down "out-lived" materials.

Ribosome

Small particles of RNA and protein found throughout the cytoplasm in all cells. These organelles produce protein by following a coded instruction that came out of the DNA.

What is the function of the cell membrane?

The cell membrane regulates what enters and leaves the cell and also protects and supports the cell.

Lipid Bilayer

A layer that gives cell membrane a flexible structure that forms a strong barrier between the cell and its surroundings, which regulates what enters and leaves the cell, gives support, and protection.

Cytoskeleton

The internal structure of a cell is supported by cytoskeleton. This organelle also helps with movement.

Smooth ER

The name is given from being the opposite of the rough ER surface. This organelle contains collections of enzymes that perform specialized tasks, including synthesis of membrane lipids and the detoxification of drugs.

Rough ER

The name is given from its ribosome-covered surface. Newly made proteins leave these ribosomes and are inserted into the rough ER, where they may be chemically modified.

What is the role of the cell nucleus?

The nucleus contains nearly all the cell's DNA and, with it, the coded instructions for making proteins and other important molecules.

Cytoplasm

The portion of the cell outside the nucleus.

Mitochondria

The power plants of the cell, which converts the chemical energy stored in food into compounds that are more convenient for the cell to use.

Organelle

They are "little organs" of the cell, which each have their own special roles.

Selectively Permeable

This means that some substances can pass across them and others cannot, which can also be called semipermeable membranes.

Microfilaments

Threadlike structures that make up a protein called actin. This produces a tough flexible framework that supports the cell. They can also help with movement.

What are the functions of chloroplasts and mitochondria?

1. Chloroplasts capture the energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis. 2. Mitocondria convert the chemical energy stored in food into compounds that are more convenient for the cell to use.

What organelles help make and transport proteins?

1. Proteins are assembled on ribosomes. 2. Proteins made on the rough ER include those that will be released, or secreted, from the cell as well as many membrane proteins and proteins destined for lysosomes and other specialized locations within the cell. 3. The Golgi apparatus modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell.

What are the functions of vacuoles, lysosomes, and the cytoskeleton?

1. Vacuoles store materials like water, salts, proteins, and carbohydrates. 2. Lysosomes break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell. They're also involved in breaking down organelles that have outlived their usefulness. 3. The cytoskeleton helps the cell maintain its shape and is also involved in movement.

Microtubules

A hollow structure that makes up protein called tubulins. They play a critical role in maintaining the cell's shape. Microtubules also play an important role in cell division, contributing with mitotic spindle, which helps in the separation of chromosomes.

Vacuole

A saclike, membrane-enclosed structures, which store materials like water, salts, proteins, and carbohydrates.

Golgi apparatus

A stack of flattened membranes, which modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell.

Cell Wall

A surrounding barrier, which surrounds the entire cells, and is used for protection, support, and shape.

Chloroplast

Biological equivalence of solar power plants, basically captures the energy from sunlight and converts it into food that contains chemical energy in a process called photosynthesis.