INTRODUCTION ‘Cell’ means a small room or chamber, cells are the structural and functional units of all living organisms. The major parts of a cell are the nucleus and the cytoplasm. The electron microscope allowed classification of cells into two major groups, prokaryotes and eukaryotes, based on the presence and absence of the true nucleus. Eukaryotes ï Eukaryotes have nucleus which is covered by nuclear membrane. (Greek: Eue = true, karyon = nucleus). Animals, plants and fungi belong to the eukaryotes. ï Eukaryotic cells are much larger than prokaryotes. ï Unlike prokaryotes, eukaryotes have a variety of other membrane-bound organelles (subcellular elements) in their cytoplasm, including:

1. SCIENCE
The natural phenomenon

2. Biology
1.Biology is the scientific study of living organisms and their
interactions with each other and their environments. It is a diverse
and dynamic field that encompasses a wide range of topics, from the
molecular and cellular levels to ecosystems and the biosphere. Here
are some key aspects of biology:
Levels of Organization:
1. Molecular Biology: Examines the structure and function of biological
molecules, such as DNA, RNA, proteins, and lipids.
2. Cell Biology: Focuses on the structure and function of cells, the basic units
of life.
3. Organismal Biology: Investigates the structure, function, and behavior of
entire organisms.
Genetics and Heredity:
4. Genetics: Studies the principles of inheritance and variation in living
organisms.
5. Genomics: Involves the study of entire genomes, including the identification
and mapping of genes.

3. Introduction
Science is a systematic enterprise that builds and organizes
knowledge in the form of testable explanations and predictions
about the universe. It is a disciplined and methodical approach to
understanding the natural world and the underlying principles that
govern its behavior. The primary goal of science is to uncover the
patterns and regularities in nature through observation,
experimentation, and logical reasoning.

4. Key features of science include:
1.Empirical Evidence: Scientific knowledge is based on
empirical evidence obtained through observation and
experimentation. This evidence is gathered using the five
senses or through the use of instruments that extend human
perception.
2.Systematic Observation: Scientists carefully observe and
gather data in a systematic manner. This involves developing
hypotheses, conducting experiments, and analyzing results to
draw meaningful conclusions.

5. • Testability: Scientific hypotheses and theories must be testable
and falsifiable. This means that there must be a way to
experimentally verify or refute a hypothesis based on
observable evidence.
Predictive Power: Successful scientific theories not only
explain past observations but also have the ability to make
accurate predictions about future events or phenomena.

6. Reproducibility: Scientific findings should be reproducible,
meaning that other researchers should be able to conduct similar
experiments and obtain similar results. This helps validate the
reliability of scientific claims.
Universal Principles: Scientific principles and laws are often
universal, applying consistently across different contexts and
environments. This contributes to the development of a unified
understanding of the natural world.

7. Branches of science
• Physical Sciences:
• Physics: The study of matter, energy, and the fundamental
forces that govern the universe.
• Chemistry: The study of the composition, properties, and
behavior of matter, as well as the changes it undergoes during
chemical reactions.
• Astronomy: The study of celestial objects, including stars,
planets, galaxies, and the universe as a whole.

8. • Life Sciences (Biology):
• Biology: The study of living organisms, their structure, function,
growth, evolution, and distribution.
• Botany: Focuses on the study of plants, including their
structure, growth, reproduction, and classification.
• Zoology: Concentrates on the study of animals, including their
behavior, physiology, classification, and evolution.

9. • Earth Sciences:
• Geology: The study of the Earth's structure, composition, and
processes, including the study of rocks, minerals, and the
forces that shape the Earth's surface.
• Meteorology: Investigates the Earth's atmosphere, weather
patterns, and climate.
• Oceanography: Examines the physical and biological aspects
of the oceans, including their currents, ecosystems, and
geology.

10. 1.Environmental Sciences:
1.Environmental Science: Focuses on the study of the environment,
including the impact of human activities on ecosystems, conservation,
and sustainable practices.
2.Social Sciences:
1.Psychology: The study of the human mind and behavior.
2.Sociology: Examines human society, social relationships, and
institutions.
3.Anthropology: Studies human cultures, societies, and their
development.

11. Physics
• Physics is the branch of science that studies the fundamental
principles governing the behavior of matter and energy in the
universe. It seeks to understand the nature of the physical
world, from the smallest particles at the quantum level to the
vast expanses of the cosmos. Here are some key aspects of
physics:

12. Chemistry
• Chemistry is the branch of science that explores the properties,
composition, structure, reactions, and changes of matter. It is
often referred to as the "central science" because it connects
and overlaps with other scientific disciplines, such as physics,
biology, and environmental science. Here are key aspects of
chemistry:

13. Biochemistry
• Biochemistry is the branch of science that combines principles
of biology and chemistry to study the chemical processes and
substances that occur within living organisms. It focuses on the
molecular mechanisms that underlie various biological functions
and processes. Biochemistry seeks to understand the structure,
function, and interactions of biomolecules, as well as the
metabolic pathways and signaling networks that regulate
cellular activities. Here are key aspects of biochemistry:

14. Enzymes
• Enzymes are biological molecules that act as catalysts,
facilitating and accelerating chemical reactions within living
organisms. They play a crucial role in various physiological
processes, contributing to the maintenance and regulation of
cellular functions. Here are key features and functions of
enzymes:

15. Chemical kinetics
• Chemical kinetics is the branch of chemistry that studies the
rates of chemical reactions, the factors that influence these
rates, and the mechanisms by which reactions occur. It provides
insights into how reactants transform into products over time.
Understanding chemical kinetics is crucial for optimizing
reaction conditions, designing efficient industrial processes, and
gaining insights into the underlying molecular mechanisms.
Here are key concepts in chemical kinetics:

16. • Reaction Order and Rate Determining Step:
• Rate-Determining Step: The slowest step in a reaction
mechanism, determining the overall rate of the reaction.
• Overall Reaction Order: The sum of the individual orders of
reactants in the rate-determining step.

17. • Carbohydrates are organic compounds comprising carbon, hydrogen,
and oxygen. They serve as a primary energy source for the body.
There are three main types:Monosaccharides: Single sugar units (e.g.,
glucose, fructose).Disaccharides: Two linked sugar units (e.g., sucrose,
lactose).Polysaccharides: Long chains of sugar units (e.g., starch,
glycogen, cellulose).Carbohydrate digestion begins in the mouth with
salivary amylase breaking down starch into smaller sugars. In the
small intestine, pancreatic enzymes further digest carbohydrates.
Absorbed sugars enter the bloodstream, regulating blood glucose
levels. Excess glucose is stored as glycogen in the liver and muscles.
Dietary fiber, a non-digestible polysaccharide, promotes digestive
health.

18. • INTRODUCTION
• ‘Cell’ means a small room or chamber, cells are the
• structural and functional units of all living organisms. The
• major parts of a cell are the nucleus and the cytoplasm.
• The electron microscope allowed classification of cells
• into two major groups, prokaryotes and eukaryotes,
• based on the presence and absence of the true nucleus.
• Eukaryotes
• ï Eukaryotes have nucleus which is covered by
• nuclear membrane. (Greek: Eue = true, karyon =
• nucleus). Animals, plants and fungi belong to the
• eukaryotes.
• ï Eukaryotic cells are much larger than prokaryotes.
• ï Unlike prokaryotes, eukaryotes have a variety of
• other membrane-bound organelles (subcellular
• elements) in their cytoplasm, including: