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BASIC CHEMISTRY. Why study Chemistry in Biology?. Biology - study of LIFE! Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Ex: glucose- C 6 H 12 O 6 water - H 2 O
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Why study Chemistry in Biology? Biology - study of LIFE! Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Ex:glucose- C6H12O6 water - H2O salt - NaCl
Composition of Matter Organisms are composed of matter. Matter is anything that has mass and takes up space. Matter is made up ofelements, which cannot be broken down by chemical reactions.
Elements Pure substances that cannot be broken down chemically into simpler kinds of matter 92 naturally occurring elements, 25 of which are essential to life. 96% of living matter is composed of 4 elements (CHON) CarbonHydrogenOxygenNitrogen
Compounds Most elements do not exist by themselves Elements combine together in a fixed ratio to formcompounds. Ex. H2O, NaCl Compounds are held together bychemical bonds. Reactivity and type of bond are determined by the number of electrons it has
The chemical bonds that are important to Biology are covalent, ionic, and hydrogen bonds.
Covalent Bond (strong) The sharing of electrons between atoms thus forming a molecule (smallest unit of compounds) such as water. Each hydrogen atom shares 2 electrons with the oxygen atom. Impt. to living things Found inBiomolecules Resulting substance isstable, and is referred to as amolecule.
Ionic Bonding • Formed between two atoms when one atomlosesan electron, and the other atomgainsan electron. • This giving & receiving results in charged particles known asions - they have an uneven# ofprotons and electrons.
Hydrogen Bonds (weak) • Occurs when H+ (which is already bonded to an electronegative atom) is ATTRACTED to anotherelectronegativeatom. • . Very weak bond Occurs betweenmolecules, not elements. Important in DNA, water. A single water molecule can form as many as 4 hydrogen bonds at the same time.