Introduction to Biology

Introduction to Biology

• Biology is the scientific study of life.
• Living organisms share common characteristics like organization, metabolism, growth, reproduction, adaptation, and response to stimuli.
• Levels of biological organization include atoms, molecules, cells, tissues, organs, organ systems, organisms, populations, communities, and ecosystems.

Characteristics of Life

• Organization: Living things exhibit a highly ordered structure, from atoms to complex organ systems.
• Metabolism: The sum of all chemical reactions in an organism, including energy acquisition and use.
• Growth and Development: Increase in size and complexity.
• Reproduction: Producing offspring, either sexually or asexually, transmitting genetic information.
• Adaptation: Evolutionary processes that favor organisms better suited to their environment, enabling survival and reproduction.
• Response to Stimuli: Ability to react to internal or external changes in the environment.
• Homeostasis: Maintenance of stable internal conditions, necessary for survival.

Basic Chemistry in Biology

• Matter: Anything that occupies space and has mass.
• Elements: Fundamental substances composed of atoms of only one type.
• Atoms: Basic units of matter, composed of protons, neutrons, and electrons.
• Molecules: Groups of two or more atoms held together by chemical bonds.
• Water: Essential for life, involved in many biological processes. A polar molecule.
• pH: Measure of acidity or alkalinity in a solution.
• Organic Molecules: Four major classes of organic molecules crucial to life: carbohydrates, lipids, proteins, and nucleic acids.
  • Carbohydrates: Source of energy, structural components.
  • Lipids: Energy storage, structural components of cell membranes.
  • Proteins: Perform diverse functions like catalysis, transport, and structure.
  • Nucleic Acids: DNA and RNA, store and transmit genetic information.

Cell Structure and Function

• Cells are the fundamental units of life.
• Prokaryotic cells lack a nucleus and membrane-bound organelles (e.g., bacteria).
• Eukaryotic cells have a nucleus and membrane-bound organelles (e.g., animals, plants).
• Major cell organelles include the nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, and chloroplasts (in plant cells).
• Cell membranes regulate what enters and leaves the cell.

Introduction to Biological Processes

• Energy: All biological processes require energy.
• Photosynthesis: Process in which plants convert light energy into chemical energy (glucose).
• Cellular Respiration: Process in which cells break down glucose to release energy in the form of ATP.
• Enzymes: Biological catalysts that speed up chemical reactions.
• Diffusion: Movement of molecules from high to low concentration.
• Osmosis: Diffusion of water across a selectively permeable membrane.

Scientific Method

• Observation: Gathering information about the natural world.
• Question: Formulating a specific question about an observation.
• Hypothesis: A testable explanation for the observed phenomenon.
• Prediction: A logical consequence of the hypothesis, if true.
• Experiment: Testing the hypothesis.
• Data Analysis: Interpreting the results of the experiment.
• Conclusion: Supporting or rejecting the hypothesis based on the data.

Scientific Ethics

• Integrity: Honesty and accuracy in research.
• Objectivity: Fair and unbiased assessment of data.
• Transparency: Open sharing of research methods and data.
• Safety: Ensuring the safety of researchers and participants in studies.
• Responsibility: Accountability for the potential impact of research.