Lecture Slides in PowerPoint by Jerry L. Cook Essentials of Human Anatomy & Physiology Seventh Edition Elaine N. Marieb Chapter 2 Biochemistry Slides 2.1 – 2.20 Lecture Slides in PowerPoint by Jerry L. Cook Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Composition of the Body Elements 96% of the body is made from four elements Carbon (C) Oxygen (O) Hydrogen (H) Nitrogen (N) Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Important Inorganic Chemicals Water Most abundant inorganic compound Vital properties High heat capacity- does not change temperature easily Chemical reactivity- serves as a base for reactions Cushioning Expands when it freezes pH of 7 (neutral) Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Important Inorganic Chemicals Salts- Vital to many body functions Include electrolytes which conduct electrical currents ex.- NaCl = sodium chloride, Ca3(PO4)2= calcium phosphate When ionic balance is severely disturbed, virtually nothing in the body works. Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Acids Acids are electrolytes/ Ionize and dissociate in H2O. They can release hydrogen ions (H+). Protons donors. HCl (Hydrochloric acid) H+ (proton) + Cl- (anion) Low pH (below 7), Taste sour If acid ionize completely: strong acid (Ex: HCl) If ionize incompletely: weak acid (Ex: acetic acid) In the body: gastric juice, uric acid, vitamin C, amino acids, nucleic acids, lactic acid, fatty acids Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bases High pH (above 7), Taste bitter, feel slippery Proton aceptors Hydroxides are common inorganic bases. They ionize and dissociate in water forming OH- ion NaOH Na+ + OH- OH- containing bases are strong Weak bases: HCO3-,NH3 Common Foods- baking soda In body: blood, semen Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Important Inorganic Compounds Neutralization reaction Acids and bases react to form water and a salt Ex.- HCl + NaOH H2O + NaCl Slide 2.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

pH Measures relative concentration of hydrogen ions (H+) in moles/L pH below 7 = acidic pH 7 = neutral pH above 7 = basic A solution with pH 6 has 10 times as many H+ ions as a solution with a pH of 7. Figure 2.11

Acid-base balance regulation in the body Cells are extremely sensitive to slight changes in pH. Kidneys, lungs and buffers carefully regulate the pH balance. Buffers are present in body fluids. Chemicals that can regulate pH change by taking up excess H+ or OH- ions.

Acid-base balance regulation in the body Homeostasis of pH is tightly controlled Extracellular fluid = 7.4 Blood = 7.35 – 7.45 < 6.8 or > 8.0 death occurs Acidosis (acidemia) below 7.35 Alkalosis (alkalemia) above 7.45

Examples of pH imbalance in the body If blood pH begin to dip into the acid range, the amount of oxigen that hemoglobin can carry to body cells begins to fall rapidly to dangerous low levels. Significant drops in pH also interferes with cell enzyme systems. It can affect electrolytes balance (Na+, K+, Cl-) and hormones

Important Organic Compounds Carbohydrates Contain carbon, hydrogen, and oxygen in roughly a 1:2:1 ratio Include sugars and starches Classified according to size Slide 2.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Carbohydrates Found in plants Functions: Used by all cells for energy Our body’s primary source of energy Slide 2.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Carbohydrates Monosaccharides – simple sugars Examples - Glucose - Galactose - Fructose - Deoxyribose - Ribose

Carbohydrates Disaccharides – two simple sugars joined Examples: Sucrose = Glucose and Fructose Maltose = Glucose and Glucose Lactose = Glucose and Galactose

Carbohydrates Polysaccharides – long branching chains of linked simple sugars Ex.- Starch and cellulose- plant polysaccharides (cellulose is indigestible) Glycogen- animal polysaccharide Stored in muscle and liver

Lipids Lipids Most are insoluble in water Contain carbon, hydrogen, and oxygen Monomers are fatty acids and glycerol Most are insoluble in water Slide 2.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lipids Can be found in oils and waxes Sometimes referred to as “fats” Functions: Energy storage To cushion organs Insulation Part of the plasma membrane Slide 2.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lipids Saturated- all single bonds Solids at room temp. Animal fats “Pile up” on sides of vessels Unsaturated- some double bonds Liquids at room temp. Plant fats Lipids http://biology.clc.uc.edu/graphics/bio104/fatty acid.jpg http://pirate.shu.edu/~rawncarr/molmodel/fattyacids.jpg

Lipids Common lipids in the human body Neutral fats (triglycerides) Found in fat deposits Composed of 3 fatty acids and glycerol Source of stored energy Slide 2.30a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lipids Common lipids in the human body (cont.) Phospholipids Form cell membranes Composed of: 2 Fatty acids Glycerol Phosphate head Slide 2.30b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lipids Figure 2.14a, b Slide 2.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Lipids: Steroids -Examples: cholesterol, bile salts, vitamin D, and some hormones Figure 2.14c Slide 2.32 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Proteins Made of amino acids 20 different amino acids Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur Slide 2.33a

Proteins Can be found in meat, animal products, and beans Functions: Maintains cell growth/formation of new body tissue Helps build and repair body tissue Aids in the contraction of muscle tissue Aids in the formation of enzymes, some hormones, and antibodies Provides energy if sufficient carbohydrates and fats are not supplied by diet Slide 2.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Proteins Essential amino acids- needed in diet Non-essential amino acids- made in body 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 Slide 2.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Proteins: Enzymes Act as biological catalysts Increase the rate of chemical reactions End in “–ase” http://www.phschool.com/science/biology_place/labbench/lab2/images/enzyme.gif

Types of Proteins: Enzymes Substrate- the substance on which an enzyme is acting Active site- the area on the enzyme to which the substrate binds http://waynesword.palomar.edu/images/enzyme5.gif

Types of Proteins: Enzymes Things that denature (deactivate) enzymes: Heat pH change Addition of ionic substances

Nucleic Acids Composed of nucleotides Sugar (ribose or deoxyribose) Phosphate Nucleotide bases A = Adenine G = Guanine C = Cytosine T = Thymine (Only in DNA) U = Uracil (Only in RNA) A bonds to T (U), G to C

DNA (Deoxyribonucleic Acid) The “Blueprint” of life Provides instruction for every protein in the body Directs growth and development Contains genes

DNA (Deoxyribonucleic Acid) Organized by complimentary bases to form double helix- 2 strands Replicates (copies itself) before cell division Makes up chromosomes/ chromatin

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 Slide 2.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

How ATP Drives Cellular Work ATP has 3 phosphates attached (P) Removal of a P releases energy from the bond, leaving ADP Removal of another P releases less energy, leaving AMP http://www.euronet.nl/users/warnar/atp.gif