Basic Chemistry

Biochemistry: Essentials for Life Organic compounds Contain carbon Most are covalently bonded Important organic compounds in the body are carbohydrates, lipids, proteins and nucleic acids. Example: C6H12O6 (glucose)

Biochemistry: Essentials for Life Inorganic compounds Lack carbon Tend to be simpler compounds Example: H2O (water), salts, and many acids and bases.

Important Inorganic Compounds Water Most abundant inorganic compounds Vital properties High heat capacity – it absorbs and releases large amounts of heat before its temperature changes, and prevents the sudden changes in body temperature. Polarity/solvent properties - “universal solvent” All reactions that occur in the body depend upon water’s solvent properties.

Inorganic Compound - continuation Water can act as a transport and exchange medium in the body. Ex. blood plasma exchange between blood and tissue cell. Specialized molecules that lubricate the body uses water as their solvent Ex. Saliva. Chemical Reactivity - It is an important reactant. Ex. To digest foods or break down biological molecules (hydrolysis reaction) Cushioning - Protects Ex. Cerebrospinal fluid and Amniotic fluid.

Important Inorganic Compounds Salts Easily dissociate into ions in the presence of water Vital to many body functions Include electrolytes which conduct electrical currents The most abundant are those containing calcium and phosphorus (bones and teeth)

Important Inorganic Compounds Acids – have a sour taste and can dissolve many metals. Can release detectable hydrogen ions-acids are also define as proton donors because the H ion is essentially a hydrogen nucleus. Bases - have a bitter taste, feel slippery Proton acceptors Neutralization reaction Acids and bases react to form water and a salt.

pH Measures relative concentration of hydrogen ions pH 7 = neutral pH below 7 = acidic pH above 7 = basic Buffers: chemicals that can regulate pH change Figure 2.11

pH: Acid-Base Concentration – (Cont.) Living cells are very sensitive to even slight changes in pH. acid-base balance is regulated by the kidneys, lungs and chemicals called buffers, which are present in body fluids.

Important Organic Compounds Carbohydrates - or hydrate carbon Contain carbon, hydrogen, and oxygen Include sugars and starches (glucose C6H12O6 and ribose C5H10O5 ) Classified according to size Monosaccharides – simple sugars Disaccharides – two simple sugars joined by dehydration synthesis Polysaccharides – long branching chains of linked simple sugars

Organic Compound - Monosaccharides Monosaccharides - are joined to form the molecules of other two groups. They are the structural units, or building blocks of carbohydrates. The most important are: Glucose (blood sugar)-universal cellular fuel. Fructose & Galactose –are converted to glucose for use by the body cells. Ribose and Deoxyribose – form part of the structure of nucleic acids.

Organic Compounds - Disaccharides Dissacarides – or double sugars Formed when two simple sugars are joined by a synthesis reaction “hydration synthesis” where a water molecule is lost as the bond forms. Ex. sucrose (glucose-fructose) which is cane sugar lactose (glucose-galactose) found in milk Maltose ( glucose-glucose) or malt sugar These large molecules must be broken down (digested)to their monosaccharide units, to be absorbed by the digestive tract by hydrolysis. A water molecule is added to each bond, then broken and the simple sugar is released.

Carbohydrates PRESS TO PLAY DISACCHARIDES ANIMATION Figure 2.12a–b

Carbohydrates PRESS TO PLAY POLYSACCHARIDES ANIMATION Figure 2.12c

Important Organic Compounds Lipids Contain carbon, hydrogen, and oxygen Carbon and hydrogen outnumber oxygen Insoluble in water They enter the body in the form of fat-marbled meats, egg yolks, milk products, and oils. PRESS TO PLAY LIPIDS ANIMATION

Lipids Common lipids in the human body Neutral fats (triglycerides) Found in fat deposits Composed of fatty acids and glycerol Source of stored energy May be solid (typical of animal fats -saturated) or liquid (plant oils -unsaturated)

Lipids Common lipids in the human body (continued) Phospholipids Form cell membranes Very similar to triglycerides (here a phosphorus containing group is always part of the molecule) Steroids Include cholesterol, bile salts, vitamin D, and some hormones

Lipids - continuation Cholesterol enters the body in animal products such as meat, eggs, and cheese. It is also made in the liver regardless of dietary intake It is found in all cell membranes, and is particularly abundant in the brain. It is the raw material used to form vitamin D, some hormones and bile salts. Cholesterol have been implicated in atherosclerosis (deposit of fatty substances in artery walls) and arterioeclerosis (hardening of the arteries)

Lipids Figure 2.14a–b

Cholesterol The basis for all steroids made in the body Figure 2.14c

Important Organic Compounds Proteins Made of amino acids Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur The building block are molecule’ s called amino acids. All have an amino group that gives them basic properties and an acid group which allows them to act as acids.

Proteins – cont. Fibrous and Globular Proteins: Fibrous or Globular proteins: are mobile, also called functional proteins. Fibrous or structural proteins. Most often in body structures. Ex collagen (bones, cartilages)

Protein Animations Click below to explore the levels of protein structure PRESS TO PLAY INTRODUCTION TO PROTEIN STRUCTURE PRESS TO PLAY CHEMISTRY OF LIFE© PROTEINS: PRIMARY STRUCTURE PRESS TO PLAY CHEMISTRY OF LIFE© PROTEINS: SECONDARY STRUCTURE PRESS TO PLAY CHEMISTRY OF LIFE© PROTEINS: TERTIARY STRUCTURE PRESS TO PLAY CHEMISTRY OF LIFE© PROTEINS: QUATERNARY STRUCTURE

Proteins Account for over half of the body’s organic matter Provides for construction materials for body tissues Plays a vital role in cell function Act as enzymes, hormones, and antibodies Enzymes are important in the functioning of all body cells. PRESS TO PLAY CHEMISTRY OF LIFE© PROTEINS: ENZYME ANIMATION

Enzymes Act as biological catalysts Increase the rate of chemical reactions Figure 2.17

Important Organic Compounds Nucleic Acids Provide blueprint of life Nucleotide bases A = Adenine G = Guanine C = Cytosine T = Thymine U = Uracil Make DNA and RNA

Nucleic Acids Deoxyribonucleic acid (DNA) Organized by complimentary bases to form double helix Replicates before cell division Provides instruction for every protein in the body Figure 2.18c

Important Organic Compounds Adenosine triphosphate (ATP) Chemical energy used by all cells Energy is released by breaking high energy phosphate bond ATP is replenished by oxidation of food fuels ATP= adenine base, ribose sugar and three phosphate groups. Phosphate groups are attached by high-energy phosphate bonds that when they are ruptured by hydrolysis, energy to do work is liberated.

Adenosine TriPhosphate (ATP) Reaction when used by the cell: ATP ADP + P + E (Adenosine (adenosine ( inorganic energy Triphosphate) diphosphate) phosphate) As ATP is used to provide cellular energy, adenosine diphosphate (ADP) accumulates, and ATP supplies are replenished by oxidation of food fuels.

Adenosine Triphosphate (ATP) Figure 2.19a

How ATP Drives Cellular Work Figure 2.20