Biochemistry The Chemistry of Living Things Unit II

Basic Chemistry I. Elements- Simplest form of matter A. Living things are made of large percentages (96 %) of the following elements: H – Hydrogen O – Oxygen N – Nitrogen C – Carbon II. Compounds- Composed of two or more different elements bound together chemically. ex. H 2 O – Water A. The two categories of compounds in biology are Organic and Inorganic compounds. 1. Organic compounds contain both the elements Carbon and Hydrogen. ex. C 6 H 12 O 6

Basic Chemistry Examples of organic compounds found in living things: Carbohydrates-sugars & starches Lipids-fats, oils and waxes Proteins-enzymes & structural proteins Nucleic acids-DNA & RNA

Basic Chemistry Organic Compounds include Carbohydrates that consist of Sugars and starches which contain Carbon, hydrogen oxygen Lipids Nucleic acids Proteins that consist of Fats and oils Nucleotides Amino Acids which contain Carbon, oxygen hydrogen Carbon, hydrogen oxygen, nitrogen and phosphorus Carbon, nitrogen, Hydrogen, oxygen

Basic Chemistry Examples of inorganic compounds found in living things: Water – H 2 O Organisms contain 60 -98% water. Water is used for transport and chemical activities inside the cells. Salts – Na. Cl Important for chemical and electrical balance within cells. Na+ Sodium & Cl- Chlorine

Basic Chemistry Minerals – Fe, Ca, and Zn etc… Generally elements used by organisms in synthesizing materials. Usually found in small amounts within these organisms. Vitamins – “Enzyme Helpers” Vitamins aid organisms by speeding up chemical processes. ex. Vitamin K – helps clot blood Vitamin D – helps body absorb Ca+

Basic Chemistry Acids, Bases and the p. H Scale - Acids contain more H+ than OH- ions - Bases contain more OH- than H+ ions - p. H paper is an Indicator that can show if a solution is acidic, basic or neutral - Neutralization reaction (HCl + Na. OH Na. Cl + H 2 O)

Basic Chemistry

Basic Chemistry n n n Biologists test for the presence of inorganic and organic substances through the use of indicators An indicator will tell you if a substance is present in your sample or not Examples of indicators include: -Benedicts solution-tests for the presence of a simple sugar (+=yes, -=no) -Lugols iodine-tests for the presence of a complex sugar -Biuret’s solution-tests for the presence of a protein -p. H paper-tests specific p. H acid of a substance -litmus paper-tests whether something is acidic or basic

Carbohydrates II. Carbohydrates -Sugars A. Generally found to contain Hydrogen and oxygen in a ratio of 2 to 1 ex. C 6 H 12 O 6 C 12 H 24 O 12 B. Carbohydrates form simple sugars (monosaccharides and disaccharides) and complex carbohydrates (polysaccharides) 1. Simple sugars- Monosaccharides have a hexagonal ring shape: Mono= one Saccharide= ring type molecule 2. Complex sugars- Di and Polysaccharides are made of two or more saccharide molecules bonded together. Di= two Tri= three Poly= many

Carbohydrates C. Monosaccharides - Simplest stable carbohydrate - Simplest type of sugar - Formed around a chain of 5 or 6 carbon atoms - Used as a quick source of energy - ex. Glucose - Structural formula of Glucose:

Carbohydrates - D. Disaccharides - More complex form of carbohydrates - Double sugar - Chain of 10 or 12 carbons - ex. Maltose - Structural formula of Maltose:

Carbohydrates E. Polysaccharides: - A complex form of carbohydrate - Poly = many - polysaccharide = many sugars together - Starch is a common name for a polysaccharide - Used in animal cell membranes, plant cell walls and as a source of stored energy in both plants (starch) and animals (glycogen)

Carbohydrates F. Names of Common Carbohydrates -Monosaccharides – Glucose, Fructose -Disaccharides – Maltose, Sucrose -Polysaccharides – Cellulose, Starch, Glycogen G. Synthesis and Hydrolysis of Carbohydrates 1. Dehydration Synthesis- Building larger molecules by removing water.

Carbohydrates 2. Hydrolysis- Splitting apart by adding water.

Lipids III. Lipids (Fats, Waxes and Oils) A. Structure- Contain the elements C, H, and O -Used primarily for storing energy in organisms -Lipids form when 3 fatty acid molecules combine with 1 glycerol molecule Acids: Structure of Fatty

Lipids n Structure of Glycerol: Dehydration Synthesis of a Lipid Molecule:

Proteins IV. Proteins A. Structure- Contain the Elements C, H, O and N -Used as building materials for body structures as well as antibodies, hormones and enzymes. -Proteins are made of units called Amino Acids B. Structure of an Amino Acid: Amino group Carboxyl group General structure Alanine Serine

Proteins Amino Acids contain: 1 Carboxyl group 1 Amino group 1 Hydrogen atom 1 Side Chain (symbolized by the letter R) this side chain is different in each different amino acid (~20 different side Groups) (~20 different Amino Acids)

Proteins Dehydration Synthesis of a Protein: (Joining Amino Acids)

Proteins n Example of a Dipeptide (the simplest Protein):

Proteins Note: If one amino acid in a peptide chain changes, the whole protein can change in structure and in function!

Enzymes V. Enzymes - A specific class of proteins that act as Organic Catalysts. Enzymes make chemical reactions go faster. - Each chemical reaction needs its own specific enzyme. A. The structure of Enzymes - All enzymes are proteins (complex Polypeptides) - Enzyme names end in -ase - Enzymes are named after the reactant (substrate) on which they work. Ex. disacchridase, protease, lipase etc.

Enzymes B. Enzyme Substrate Model (The Lock and Key Theory) - This is an association between enzymes and substrate (see above). - Only certain substrates can fit in certain enzymes. - A substrate binds to an enzyme at the enzymes active site. - A chemical reaction takes place (molecules are rearranged). - The new molecules leave the active site. - The enzyme can now move on to other substrate. - The enzyme looks like a lock, the substrate a key fitting into the lock

Enzymes n Enzyme Substrate Model:

Enzymes C. Factors Affecting Enzyme Rates of Reaction 1. Temperature As the temp increases the rate of reaction increases… UP TO A POINT, then the rate of reaction quickly drops off. At temperatures that are too high, enzymes start to break down. This is process is called Denaturation. Human body temp is 37˚C, this is the perfect temperature for most human enzymes. Denaturation begins at 40˚C.

Enzymes 2. Concentration affects enzyme rates -If there are more enzymes, they can perform more chemical reactions (until substrate molecules run out) -If there is more substrate for an enzyme to work on, this too will cause an increase in the rate of chemical reactions. (Until that enzyme reaches its maximum rate) 3. p. H affects enzyme reaction rates - Enzymes work best at a certain p. H - Enzymes are specific to the acid, base or neutral environment in which they work

Enzyme Activity vs. Ph for 3 different enzymes

Enzyme Activity vs Temperature