Login with Facebook

The structure of cell: a research on the bricks of the human body!

We are made up of 100,000 billion cells. Understanding the basic composition and functioning of the cell can help us understand what happens at more complex levels of organs. The first phase is called chemical evolution, from very simple molecules such as hydrogen, ammonia, methane, monoxide, and carbon dioxide, by the action of ultraviolet radiation (sun), heat, and electric discharges (lightning). They are very reactive intermediate molecules formed such as acetaldehyde, hydrogen cyanide, formaldehyde, and perhaps even some simple fatty acids such as acetic acid and some simple amino acids such as aniline.

A second phase followed, called biological evolution, in which more complex molecules of acids, amino acids, proteins, and especially nucleic acids were formed.

- The first prokaryotic cell (plant cell) appeared about 3.5-3.0 billion years ago.

- The first eukaryotic cell (animal cell) appeared much later, around 0.9 billion years ago. 

- Homo sapiens made his appearance 400,000 years ago.

Hypothesis on the origin of the cell

According to Jacques Monod and other authors, the gradually increasing order structures formed in the cell are determined by the genetic information contained in the DNA from the primary sequence of a polypeptide chain. There are gradually the secondary and tertiary structures of the proteins, then the formation of compounds oligomeric, and finally, by the interaction between proteins, lipids, and nucleic acids, the formation of the first simple plant cells.

Probably, only with the appearance of the genetic code was it possible to determine the formation of the first heterotrophic prokaryotic cell (which feeds on organic molecules) and anaerobic (which lives in the absence of oxygen). Subsequently, autotrophic prokaryotes appeared (using the food synthesized inside), obviously provided with photosynthetic pigments.

With the appearance and accumulation of oxygen, the first autotrophic and aerobic prokaryotic cells are born. In turn, this type of cell opens the way for the formation of the first eukaryotic cell, which appears after 2.6-3.1 billion years after that of the prokaryotic cell.

The structure of a eukaryotic cell

The cells have uniform morphological characters only in the simplest organisms; in others, the cells differ in shape, size, and tasks.

There are two types of cells

1. Eukaryotic cell (animals and humans), which contains a cell nucleus delimited by a nuclear membrane and separate organelles;

2. Prokaryotic (plant) cells: These cells are instead free of the nuclear membrane and intracellular organelles, with the exception of ribosomes.

In cells, we can distinguish:

Cell membrane

The typical structure of the cell membrane consists of a double phospholipidic layer between two protein layers located at the level of the separation surfaces between the internal and external phases of the cell. Water enters and exits easily, while for many other substances, this passage is not so easy.

This ability of the membrane to allow or not the passage of substances is called “selective capacity.”

Core

It constitutes the most important part of the cell by controlling all its activities. For example, the nucleus brings hereditary information to the cell for the construction of a "unique" type of organism. It directs the cell's activities, ensuring that the complex molecules that the cell requires for the realization of the various cellular activities and for the formation of organelles and other structures. They are of the necessary number and type; decides when the right time for cellular reproduction is and controls all phases.

The nucleus is wrapped in the nuclear membrane that separates it from the cytoplasm. The nuclear membrane is sprinkled with numerous small holes called nuclear pores, due to which various substances pass from the cytoplasm into the nucleus.

The nucleus contains DNA combined with proteins (chromatin). Chromosomal DNA performs two types of activity, i.e., auto synthetic and all-synthetic; in the first case, the DNA molecule is replicated through a semi-conservative process; in the second case, it synthesizes the three types of RNA. When the cell divides, chromosomes form from the chromatin. The cell genome is inherent in the chromosomes. Inside the nucleus, there is a very dense body, the nucleolus, also formed, like chromosomes, by DNA and proteins; a particular type of RNA, ribosomal RNA, is also formed in the nucleolus.

Cytoplasm

It is the viscous substance between the cell membrane and the nuclear envelope. The majority of cellular activities take place inside the cytoplasm, and the energy necessary for the life of the cell is also produced. In it, there are organelles used for the various functions that the cell must perform. They are:

Mitochondria

Microscopic power plants, where the formation of ATP (energy necessary for cells) takes place through biochemical reactions

RIBOSOMES

They are of fundamental importance because protein synthesis occurs in them. Ribosomes are the most numerous cell organelles; they consist of two subunits, a major and a minor, which dissociate at the end of each protein synthesis cycle. The RNA sequence is translated into the corresponding sequence of amino acids assembled to form the protein. The ribosome is, therefore, an apparatus for synthesizing proteins, capable of bringing together in the appropriate arrangement the molecules necessary for the synthesis reaction.

LYSOSOMES

Intracellular vesicular organelles delimited by a single membrane, containing various enzymes, and localizable around the nucleus It can be considered the digestive system of the eukaryotic cell, for the action, carried out by the various enzymes with degradation. For example, of glycoproteins and glycolipids by means of lysosomal hydrolases, and degradation of senescent components of the same cell, as well as recycling and transport of degraded molecules to the sectors where they are necessary for the synthesis of new products, with consequent energy savings.

ENDOPLASMATIC RETICLE

Dynamic structure, which increases or decreases according to cellular activity. In cells, we have the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The first one is ribosomes, which are attached and involved in the synthesis and the transport of proteins out of the cell. The second, which physically is a portion of the same rough endoplasmic reticulum, but is free of ribosomes, is important in the synthesis of lipids.

DNA and the genetic code

The following concepts serve to deepen how the DNA of a cell, for example, establishes which proteins are needed by our body and when they are needed.

DNA is present in all cells capable of reproducing. Even if it does not take part directly in protein synthesis, DNA contains the code to build all the proteins that are needed starting from the 20 amino acids, most of which are also synthesized by cells, except for some amino acids which must necessarily be introduced with the diet, and which therefore are called essential Deoxyribonucleic or deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic information necessary for the biosynthesis of RNA and proteins. 

DNA structure

DNA is an organic polymer made up of monomers called nucleotides.

All nucleotides are made up of three basic components:

1. a phosphate group;

2. deoxyribose (pentose sugar);

3. A nitrogenous base that binds to deoxyribose with an N-glycosidic bond.

Four nitrogen bases can be used in the formation of nucleotides and incorporated in the DNA molecule, i.e., adenine (A), guanine (G), cytosine (C), and thymine (T).

The genetic code

To preserve and exchange genetic information, in over 3 billion years, nature has built the genetic code. The DNA contains adenine, thymine, guanine, and cytosine. Three base pairs form a codon, which identifies either a specific amino acid to be used for protein synthesis, or a signal to stop the synthesis itself. Almost all living things use the same genetic codehuman cell structure, called the standard genetic code.


Comments




Send Comment

Need a custom
essay?

We will write it for you.
Order now

Free Essay Examples

Free essays:

Analysis of Business Cycles
Analysis of Fiscal and Monetary Policies
An Overview Of Economic Studies
A Guide to Pricing Strategies
Biosensors for cancer diagnosis
Business Analysis: Pricing strategies and Demand Curve
Broadcasting: How to Be Good In Front of the Camera
Bioconjugates for the Drugs Delivery
Cells of Immune system
Challenges that IT Managers are facing
Cochlear implant: what it is and how it works
Current challenges to the health of women
Doppler ultrasound or simply eco Doppler
DNA extraction
Dynamic Systems Modeling with Machine Learning
Digital Imaging: What Is It?
Economy analysis: Business Cycle and Economic Trends
Exchange rate and foreign currency risk
Economic Factors Affecting Decision Making In A Business
Economy Analysis: Inflation, Unemployment And Policies
Factors Influencing Interest and Exchange Rates
Fiscal and Monetary Policies in Response to 2008/2009
Fermentation: how it works and what it is used for
Financial Markets and Functions
Genetic regulation networks: modeling in biology
How can immigrants blend in the American society?
How to make your business survive at economic crisis
How to choose the topic of the senior capstone project
Importance of corporate sustainability
Interaction of Consumer and Firm Choices in Markets
Introduction to Microeconomics
Introduction of Microfabrication techniques
Journalism: What is News?
Journalism: Broadcast media and Television Presenters
Journalism: Sources of News
Journalism and Law
Key Determinants of National Income
Key Factors That Affect Pricing Decisions
Kinetic models in biology and Related fields
Know about the different forms of traditional African dances
Latest technology trends
Latest dance trends
Methods of labeling of nucleic acid that enable their detection
Macroeconomics: International Economic Issues
Neuromuscular disorders
National Economies, Fluctuation, and Responses to Fluctuations
Neurotransmitters: what they are and different types
Nanomedicines to target tumors
Overcoming Hiring Challenges for Nonprofit Organization
Principles of Microeconomics - Producer Theory
Principles of Microeconomics - Consumer Theory
Principles of Economics
Role of technology in the modern business environment
Role of Homeostasis in Human Physiology
Role of a digital artist
Role of gender studies
Skills in Journalism: Effective Interview
Systems biology - An understanding the functioning of biological systems
Self-assembly for biological systems
School of American Ballet
Types of corporate responsibility
The Role of Government Policy in Improving Economic Outcomes
Types of bioreactors and their applications
Technological perspectives and reflections of neural engineering
Understanding Perfect and Imperfect Competition
Ultrasound: physical principles and image formation
Understanding social entrepreneurship
Understand the importance of investigative journalism
Various theoretical perspectives of sociology
Virtual reality, what it is and how it works
What are the Causes of financial instability?
What is business ethics and code of ethics
4 Facts about Origin of Mathematics!
5 techniques to create an animation
10 strategies to maximize corporate profits
13 Best colleges for political science in the world
6 Medical Technologies that revolutionized the healthcare in 2020
All you need to know about the ACA Code of ethics
Architecture and Democracy: An Introduction
Architecture and Democracy: Democratic Values
Architecture and Democracy: Democratic Procedures
All You Need to Know About a Synthesis Essay
An essential guide to understanding Film Theory
Application of Artificial Intelligence in Cyber Security
Applications of electrical engineering
Augmented reality: what it is, how it works, examples
Advantages And Disadvantages Of Social Networking
All you need to know about Cryptography
Applications of astrophysical science
All you need to know about architecture engineering
Applications of geological engineering
Artificial intelligence and medicine: an increasingly close relationship
An insight into Computational Biology
ACA code of conduct
A Rose for Emily
Applications of Mathematics in daily life
Architecture mistakes to avoid
All you need to know about Toxicology
All you need to know about Holistic Medicine
All you need to know about linguistics
An introduction to Linguistics and its subfields
All you need to know about Anxiety disorder
All you need to know about Drones
A Brief Insight into Political Science
Assumptions related to feminism
All you need to know about Byzantine emperors
All you need to know about labour economics
An insight into xenobots -the first-ever robots
An ultimate guide about Biomaterials
A Comprehensive Introduction to the Mona Lisa
Analysis methods of Transport through biological membranes
An ultimate guide about biochemical reactions
Analysis of brain signals
Artificial Gene Synthesis
Application to synthetic biology of CAD methods
All you need to know about metabolic pathways
Applications of BIOMEMS
All you need to know about the epidemiology
Asian vs. western leadership styles
All you need to know about Smart prosthesis
Analysis of Economy: Output of Goods and Services (GNP), and GDP on Economic success
A Guide to Pricing Strategies
An Overview Of Economic Studies
Analysis of Fiscal and Monetary Policies
Analysis of Business Cycles
How to Write a Personal Essay
Housing Needs in America
How to Write a Description Essay
How to Create an Excellent Scholarship Essay?
How to write a cause and effect essay
How to Hire the Best Essay Writing Service Provider?
How to Write a College Application Essay?
How to get the most out of your English lectures
How to write Expository Essay
How to succeed in your psychology class?
How to Write an Academic Essay in the Shortest Time?
History of Journalism
How Different Sectors are Using Artificial intelligence (AI)
How to write an informative essay
How to deliver persuasive essays?
How to Give a Convincing Presentation
How to write an essay on leadership?
Historical Art Still Around Today
Humanoid robot: what it is, how it works and price
History of Chemistry
Healthcare Advanced Computer Power: Robotics, Medical Imaging, and More
Healthcare AI: Game Changers for Medical Decision-Making and Remote Patient Monitoring
How to understand different types of English
How to Cope with Chronic Pain
How African American choreographers and dancers have influenced American dance
How mobile robot can do in logistics or in production
How To Become a Successful Entrepreneur
History of the Philosophy of Feminism
How is the climate changing?
How to Track Your Content Marketing ROI
How to Gun control In the USA?
Historical and contemporary role of labour in the modern world
How breast cancers are classified?
How the cells of our body communicate?
How the Lymphatic System Works?
How Digestive System Works
How to complete your capstone projects effectively?
How to write a research project
Healthcare technologies that help patients with better self-management
How to choose the topic of the senior capstone project
How to make your business survive at economic crisis
How can immigrants blend in the American society?
The Looming Energy Crisis in America
Top benefits of performance-based engineering
The More Languages You Know, The More Times You Are a Man
Things to consider while writing an Argumentative Essay
Top Ways to Improve Your Academic Writing Skills
Tips to Excel in Creative Writing
The origins of films in the early 19th century
Top career options in Architecture
The Elevator Pitch
Top finance trends 2020
The basic Structure and functionality of robots
The Way to Success
The election system of the President in the United States of America
Two-party System in United States of America
Top trends in urban design
The history and theory of African American filmmaking
Top benefits of creative writing
Tinnitus Guide: Common Symptoms and Treatment Options
The language of dance
The digital image processing management
Top famous politicians of the World
Top methods of political science!
The history of the feminist movement
The blood flow in cardiovascular system - Biofluid Mechanics
The best of Leonardo Da Vinci
The Structure and Function of Macromolecules
The structure of cell: a research on the bricks of the human body!
Tissue and organ construction: Adhesion and recognition between cells
The kinetics of the transformation processes
The Modeling of Biological Systems
Tips for writing a great thesis statement
The Defense mechanisms against infections
The impact of the technological innovations in medicine
Top journalism trends to know about
The relation between mass media & politics
Theranostics: Diagnosis and Care through Nanoparticles
The practical Applications of X-rays
The applications of Ultrasound in medicine
Transfer mechanisms of genetic information in Bacteria
The regulation of cellular metabolism in the diagnosis
The Principles of MRI Contrast agents
The technical basis of optical coherence imaging
The New Media: Emerging Trends
The Structure of Interest Rates and the Yield Curve
Technological perspectives and reflections of neural engineering
Types of bioreactors and their applications
The Role of Government Policy in Improving Economic Outcomes
Types of corporate responsibility
What is a Definition Essay?
What are diagnostic essays?
What is the relation between art structural engineering?
What is a Narrative Essay
What are robotics and intelligence systems?
What are the benefits of studying health sciences?
What is artificial intelligence and why it matters?
What is comparative Literature?
Why study neuroscience
What is Wi-Fi and how does it works
What is French history famous for?
What are Humanistic Studies?
What is covered in Biophysics?
What is modern journalism?
What is Virtualization? Benefits & Applications
What are modern public relations?
What is plasma physics?
What is teacher preparation?
What is rapid prototyping for 3D printing?
What is contemporary European Politics?
Why should you learn American Ballet?
What is engineering physics?
What is the purpose of African American Literature?
Ways to learn the Rhythm
What is digital art used for?
What are Enzymes and how do they work
Who is the father of political science?
Why Study Political Science - Job?
What is the Philosophy of Feminism?
What is a quantum computer?
Ways B2B Startups Streamline Their Conversion Strategies
Why do biomedical signals need processing?
What are the long term effects of climate change?
Why study labour relations
What is Holoprosencephaly?
What is antisocial disorder?
What are the important principles of evolution?
What is the cytoplasm and its function?
What is biopolymers?
What Makes a Good Leader
Women empowerment in modern generation
What is the history of political thought?
What is Gene recombination
What is synthetic biology
What is business cost analysis?
What is Inflation
What are the consequences of unemployment?
What is lithotripsy and its types?
What is transition elastography?
What is the purpose of deep brain stimulation?
What is a Brain-Computer Interface (BCI)
What is neuroethics?
What is Market and Supply and Demand
What is optogenetics?
What are the techniques to record brain activity?
What happens if the interest rate increases?
What is immunotherapy?
What is the economic role of the financial market?
What are the factors behind illegal immigration?
What is the lymphocyte activation?
What is financial market and its types?
What is the structure of financial markets?
What are the methods of measuring business performance?
What is the Credit market?
What is business ethics and code of ethics
What are the Causes of financial instability?