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

2. Biochemistry Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Studies the chemistry in living organisms Our bodies stay alive due to hundreds of chemical reactions taking place inside of us each day Chemistry is what allows our bodies to function so biochemistry is a big part of physiology

3. Matter and Energy Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Matter – anything that occupies space and has mass (weight) Energy – the ability to do work Chemical Electrical Mechanical Radiant

4. Forms of Energy Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Kinetic = actually doing work moving, we have constant motion in our bodies plus plenty of movement outside Potential = inactive or stored, found as chemical energy stored in our body both as ATP and fat

5. Forms of Energy Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chemical – stored in bonds of food, ATP and fat; a type of potential energy Electrical – occurs in bodies when electrolytes move across cell membranes; needed to contract muscles, keep heart beating, send messages along nerves, etc Mechanical – directly involved in moving matter, like blinking, waving, riding a bike Radiant – travels in waves like light, UV or X-rays; need some UV to stimulate our bodies to make vitamin D

6. Composition of Matter Slide 2.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Atoms Smallest particle; make up the elements Elements Pure substances – only 92 natural ones 96% of the body is made from just four elements Carbon (C) Oxygen (O) Hydrogen (H) Nitrogen (N)

7. Atomic Weight and Isotopes Slide 2.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Isotopes Atoms of the same element that have the same number of protons, but different number of neutrons The atom behaves just like other atoms of that element but is a little heavier or sometimes lighter Usually they lose the extra neutrons over time = radioactivity (but isn’t always bad)

8. Radioactivity Slide 2.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Radioisotope Heavy isotope Tends to be unstable Decomposes (loses neutrons) to more stable isotope Radioactivity Process of spontaneous atomic decay

9. Radioactivity Slide 2.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Radioisotope Serve several important medical purposes Used to tag biological molecules to follow through the body for diagnoses Used in PET scans to look at soft tissues that X-rays don’t see well Use radium & cobalt in radiation therapy for cancer It’s even used in your smoke detectors!

10. Reactive Elements Slide 2.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Every element except helium, neon, argon, krypton & radon is reactive Elements need to gain, lose, or share electrons Allows bonds to form, which makes the atom stable and uses less energy Figure 2.4b

11. Chemical Bonds Slide 2.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Ionic Bonds Form when electrons are lost by one atom and gained by another atom One atom becomes positive (lost electrons) or a cation; the other atom becomes negative (gained electrons) or an anion We need ions or electrolytes in our body for the muscles and nerves to communicate, examples are sodium, phosphate, iron, calcium and magnesium.

12. Chemical Bonds Slide 2.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Covalent Bonds Some atoms share electrons to become stable, and don’t become charged ions Many substances we utilize in our body are covalently bonded: hydrogen, water, oxygen, carbon dioxide, fats (lipids), proteins & carbohydrates Atoms don’t always share their electrons equally, unequal sharing = polar covalent bond Water is really polar and makes up a big % of our bodies so this is a big deal Figure 2.6c

13. Patterns of Chemical Reactions Slide 2.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synthesis reaction (A+B  AB) Atoms or molecules combine Energy is absorbed or needed for bond formation Example: building muscle or new tissue which burns calories, repairing damaged cells Always occurs with anabolic or constructive activities

14. Patterns of Chemical Reactions Slide 2.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Decomposition reaction (AB  A+B) Molecule is broken down Chemical energy is released Example: digesting food and breaking it into smaller components; the liver breaking down glycogen to increase the glucose level in the blood Always present in catabolic (destructive) activities.