Essay about The Human Cell

Submitted By be169
Words: 663
Pages: 3

The Human Cell
In this assignment I am going to outline the functions of the main cell components within the human cell.
Cell Membrane
The cell membrane is a protective layer that decides what can enter and leave the cell, it only allows certain substances in and out. It is a phosphor lipid bi layer that surrounds the cytoplasm of the cell. Only small uncharged molecules can pass through the membrane and this is done through a process called diffusion, protein molecules allow substances to pass in and out. Oxygen, Carbon dioxide and fat soluble drugs are some of the small molecules that can pass through the membrane. The structure of the cell membrane is made up of phosphor-lipids which are arranged in two layers which are called bi-layers.
The nucleus is the largest structure inside the cell; it contains DNA which holds genetic information. Almost all of the cells activities are controlled by the nucleus as it provide instructions for protein synthesis. The structure of the nucleus membrane is similar to the structure of the cell membrane but it also contains gaps that allow nucleic acids and proteins to pass through. There are three main parts to the nucleus; the nuclear envelope, chromatin and chromosomes and the nucleoli.
The cytoplasm refers to anything inside the cell boundary and outside the nucleus. The cytoplasm is a fluid like material that is similar in consistency to that of gel meaning it can flow slowly throughout the cell. Many chemical reactions take place within the Cytoplasm. The term for the reactions that take place in the cytoplasm is metabolism. The cytoplasm contains various organelles that all have different functions and are essential for the survival of the cell.
Rough Endoplasmic Reticulum
The rough endoplasmic reticulum have ribosomes on their membrane, these ribosomes synthesise proteins.
Smooth Endoplasmic Reticulum
There are no ribosomes on the smooth endoplasmic reticulum which means they are not involved with protein synthesis. The SER carries out many different functions but primarily, the SER is responsible for the making and breaking down of fats.

Golgi apparatus
The Golgi apparatus is a number of fluid filled disk shaped sacs that are stacked and bound by a membrane. The Golgi apparatus sorts, process and packages protein in order to deliver it to other organelles. The Golgi apparatus also produces lysosomes.
Mitochondria are sausage shaped when looked at under a microscope. They are the main power of the cells as they produce most of the energy that the cell requires in