Biology and Chemistry Basics

Study Notes

Basic Biological Concepts

Biology is the study of life, encompassing a vast range of topics from the smallest molecules to the largest ecosystems.
Living organisms share several key characteristics:
- Cellular organization: All living things are made up of cells, which are the basic units of life.
- Metabolism: Living organisms carry out chemical reactions that require energy, such as photosynthesis and respiration.
- Homeostasis: Living organisms maintain a stable internal environment, despite external changes.
- Growth and development: Living organisms grow and develop over time.
- Adaptation: Organisms adapt to their environments over generations through evolution.
- Response to stimuli: Living organisms respond to changes in their environment.
- Reproduction: Living organisms produce offspring.

Basic Chemistry Concepts Relevant to Biology

Matter is anything that has mass and occupies space. It's composed of elements.
Elements are pure substances that cannot be broken down into simpler substances by chemical means. They are represented by symbols (e.g., C for carbon, O for oxygen).
Atoms are the smallest units of an element that retain the chemical properties of that element; they are composed of protons, neutrons, and electrons.
Compounds are substances formed by the chemical combination of two or more different elements in definite proportions. The atoms are held together by chemical bonds.
Chemical bonds link atoms together. Types include:
- Ionic bonds: One atom gives up one or more electrons to another atom, forming ions with opposite charges that attract.
- Covalent bonds: Atoms share one or more pairs of electrons.
- Hydrogen bonds: A weak attraction between a slightly positive hydrogen atom and a slightly negative atom (e.g., oxygen or nitrogen).
Chemical reactions involve the breaking and forming of chemical bonds.
Water is a crucial molecule for life, possessing unique properties that support biological processes:
- Polarity: Water molecules are polar, leading to hydrogen bonding.
- High specific heat capacity: Water can absorb significant amounts of heat without a large change in temperature.
- High heat of vaporization: A lot of energy is required to convert liquid water to water vapor.
- Excellent solvent: Water dissolves many substances (polar and ionic).
- Cohesion and adhesion: Water molecules stick to each other and other substances.
pH and acids/bases:
- pH measures the concentration of hydrogen ions (H+) in a solution.
- Acids release H+ ions, while bases accept them. A pH scale measures this.
- Buffers are substances that resist changes in pH.

Interrelationship of Chemistry and Biology

Biological molecules: Large molecules, like carbohydrates, proteins, lipids, and nucleic acids, are crucial for life's functions, and their structure and function are determined by chemical properties.
Chemical reactions are fundamental to all biological processes. For example, photosynthesis involves complex chemical reactions utilizing light energy and carbon dioxide to produce glucose.
Metabolism is the sum of all chemical reactions in an organism, including those that release energy (catabolism) and those that require energy (anabolism).

Description

This quiz covers fundamental concepts in biology and chemistry, including the characteristics of living organisms and the nature of matter. Learn about cellular organization, metabolism, homeostasis, and the elements that compose matter. Perfect for students exploring the foundational aspects of life sciences.