DSCI112 Biochemistry Mid-Session Notes PDF

DSCI112: Molecules, Cells and Organisms Lecture 1: Chemistry of Life 1  Lecture 1: Chemistry of Life This lecture introduces some basic concepts of chemistry that apply to the study of life, including the ordering of at...

DSCI112: Molecules, Cells and Organisms Lecture 1: Chemistry of Life 1  Lecture 1: Chemistry of Life This lecture introduces some basic concepts of chemistry that apply to the study of life, including the ordering of atoms into molecules. Most organisms are made mostly of water and live in an environment dominated by water. In this lecture we look at the properties of water that make it so indispensable to life on Earth. Lecture outline: This lecture is based upon content within 1. Elements and atoms Chapters 2 & 3 of Campbell Biology, 12th Edition 2. Molecules and bonds 3. Properties of water 2 Lecture 1: Learning outcomes Describe what an element is and be able to list the main elements composing life. List the components of an atom, describe how they are arranged and the significance of each part. Describe the strong bonds which hold atoms together in a molecule and the weak bonds which hold molecules together. Discuss how hydrogen bonds give water its unique properties. 3 1. Elements and atoms Organisms are made up of matter (anything that takes up space and has mass) 11  Matter is made up of elements Na An element is a substance that cannot be broken Sodium down to other substances by chemical reactions 22.9898  Chemists recognise 92 elements occurring in nature Some symbols are derived from Latin or German; for instance, the symbol for Each element has a symbol, usually the first letter or sodium is Na, from the two of its name Latin word natrium 4 All life is composed of the same few elements About 20-25% of the 92 natural elements are essential to life Four elements make up 96% of the living parts of organisms  hydrogen (H)  oxygen (O)  nitrogen (N)  carbon (C) An essential element is one required for health and reproduction Trace elements are only required in minute quantities (