1 Biochemistry The study of the chemistry of life. Textbook Chapter 2

2 Chemistry Review Atom – Basic unit of matter. Subatomic particles of atoms: –electrons – negatively charged particle in constant motion around the nucleus. –protons – positively charged. (Equals atomic #) –neutrons – No charge. *Protons & Neutrons form the nucleus of an atom.

3 It’s elemental… Element – a pure substance that consists entirely of ONE type of atom and more than 100 known elements. There are only about 2 dozen found in living organisms. Compound – Substance formed by the chemical combination of 2 or more elements.

4 Bonding Ionic Bonds -When electrons are transferred from one atom to another. –Involves a metal and a non-metal

5 Bonding, cont. Covalent Bonding – between two or more non-metals. Electrons are SHARED. –Most of your compounds in biology are covalently bonded!

6 Covalent Bonding in Water Oxygen shares its 6 electrons Each hydrogen shares 1 electron Oxygen now has 8 electrons around it all times!

7 Properties of Water Water is the single most abundant compound in living things. Water has an unusually high boiling point and freezing point Water expands when frozen and is less dense as a solid Polarity – molecules in which the charges are unevenly distributed that attract like a magnet. This allows water molecules to easily attract other water molecules.

8 States of water

9 Adhesion and Cohesion Water is attracted to other water. This is called cohesion. Water can also be attracted to other materials. This is called adhesion. The oxygen end of water has a negative charge and the hydrogen end has a positive charge. –The hydrogens of one water molecule are attracted to the oxygen from other water molecules. This attractive force is what gives water its cohesive and adhesive properties.

10 Surface Tension Surface tension is the name we give to the cohesion of water molecules at the surface of a body of water. –All the water molecules on the surface of the bead are 'holding' each other together or creating surface tension.

11 Capillary Action Capillary action is related to the adhesive properties of water. You can see capillary action 'in action' by placing a straw into a glass of water. The water 'climbs' up the straw. Plants use capillary action to pull water into themselves

12 Solutions and Suspensions Mixture – Materials composed of 2 or more elements or compounds physically mixed together but not chemically. –Ex: salt and pepper: New substance NOT formed.

13 Solutions Types of mixtures made with water: 1. Solutions – components are evenly distributed. a. Solute – substance that is dissolved. b. Solvent – substance which does the dissolving. Watch this flash movie!flash movie *Water is the universal solvent.

14 Acids and Bases pH Scale – scale used to determine the concentration of Hydrogen+ ions in a solutions. Scale ranges from 0 – is an equal # of H ions (balance). Below 7= acidic/ Above 7= basic. Acid – high concentrations of H ions. Base – low concentrations of H ions.

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16 More about pH Buffer – weak acid or base that can react with strong acids or bases to prevent sharp, sudden changes in the pH level. *Maintaining pH is essential to maintaining homeostasis in living things.

17 Suspensions Suspension – Mixtures of water and no dissolved materials. –Blood is an example of a suspension. Can you name these other examples?

18 Carbon Compounds The basis of biochemistry

19 Organic Chemistry – Is the study of compounds that contain carbon atoms. Carbon can: 1.Bond with many different elements. 2.Forms millions of different, large complex structures. *No other element comes close to the versatility of carbon which is why it is found in living things.

20 Molecule size Macromolecule – Giant molecules. Monomer – smaller molecules Polymer – many joined monomers.

21 Saturated vs. Unsaturated Saturated Fats – solid form of fats. These fats do not break down easily. They can cause hardening of the arteries. Only found in animal products. Polyunsaturated Fats – liquid at room temperature. Ex: cooking oils, such as corn, sesame, olive oil. Found in plant products.

22 Nucleic Acids Nucleic Acids – macromolecule - largest in the body. Forms and transmits the genetic code. Nucleotides – polymers assembled from individual monomers. –3 parts: Sugars/ Phosphates/ Nitrogen Bases.

23 Nucleotides 2 types of Nucleotides: –a. DNA – deoxyribonucleic acid. The master copy of the information code. –b. RNA – ribonucleic acid. Makes protein molecules.

24 4 Groups of Organic Compounds of Living Things

25 Carbohydrates Carbohydrates – main source of energy in living things. (starches/sugars) –a. monosaccharides – single sugar molecules. Glucose, galactose (milk), fructose (fruits) –b. polysaccharides – excess sugar stored in animals & plants. 1. glycogen – sugar stored as in animal tissues. 2. Cellulose – sugar stored in plant tissues. The tough, flexible fibers found in plants.

26 Lipids Lipids – not soluble in water. Fats, oils, waxes. –Store energy, –make up membranes –coverings in living things –Steroids are lipids too.

27 Proteins Proteins – polymer of molecules called amino acids. –Each protein has a specific job such as cellular components and muscles and bones.

28 Amino Acids Amino Acids – building blocks of proteins. More than 20 types found in nature.

29 Chemical Reactions & Enzymes *Everything that happens in an organism. Growth, interactions with the environment, movement, etc. are based on chemical reactions. Chemical Reaction – process that changes 1 set of chemicals into another. Always involves change and cannont be undone.

30 Chemical Reactions Energy exchanges – energy is released anytime chemical bonds form or break. Activation energy – energy needed to get a reaction started. Enzymes – proteins that speed up chemical reactions. Catalyst – substance that speeds up the rate of chemical reactions

31 How do Enzymes Work? 1. Substrates – sites where reactions can be brought together. Bonds to the site on the enzyme which fits just right like a lock and key. 2. Regulation – cells that contain proteins that can turn “on” or “off” enzymes when needed.