Biochemistry: The branch of chemistry that relates directly to life processes

1. Biochemistry:The branch of chemistry that relates directly to life processes Chemistry of Life: Chapter 2

2. Basic Chemistry: • Matter: • Anything that occupies space and has mass • Exists as solid, liquid, or gas Examples of each state are found in the human body… solid bones, teeth liquid  blood gas  air we breathe

3. Energy • Contrasts to matter because it is massless and does not take up space • Can only be measured by its effects on matter • Commonly defined as the “ability to do work” or “put matter into motion” • Really important inside the body and there are several types….

4. Forms of Energy with Anatomy Connections: • Chemical: • Stored in bonds of chemical substances Anatomy Connection: All body cavities are “run” by the chemical energy harvested from the foods we eat

5. Forms of Energy with Anatomy Connections: • Electrical: • Results from movement of charged particles Anatomy Connection: In your body, an electrical current is generated when charged particles (ions) move across cell membranes… Why do “tasers” work?

6. Forms of Energy with Anatomy Connections: • Mechanical: • Directly involved in moving matter Anatomy Connection: As the muscles in your legs shorten, they pull on your bones, causing your limbs to move-so you can do things like pedal a bike, smiling, waving at someone

7. Forms of Energy with Anatomy Connections: • Radiant: • Travels in waves, that is, energy of the EM spectrum which includes X-rays, infrared, visible light, radio, microwaves, UV light, etc… Anatomy Connection: Light stimulates your eyes so you can see….UV waves give you your suntan and stimulates production of Vitamin D

8. Energy Conversions • With few exceptions, energy is converted from one form to another… • In the body, chemical energy of foods is trapped in the bonds of a high-energy chemical called ATP and ATP’s energy may ultimately be transformed into the electrical energy of a nerve impulse or mechanical energy of shortening muscles

9. Energy Conversions & Heat • Energy Conversions are quite inefficient • Some energy is “lost” to the environment as heat. (It is not really lost because energy cannot be created or destroyed, but the part given off as heat is unusable so we call it lost) • All energy conversions that occur in the body liberate heat • It is this heat that makes us warm-blooded animals and contributes to our relatively high body temperature, which has an important influence on body functioning (the higher the temperature, the faster chemical reactions in the body can occur)

10. R.A.F.T. & GISTExplaining how the Taser Shotgun shell WorksTaser Video • R (Role of Writer): Who are you as the writer? You are a friend trying to explain something to another friend. • A (Audience): To whom are you writing? Your troublesome friend who was recently shot with a Taser because he ran from the cops at a party. • F (Format): What form will the writing take? A short, easy to comprehend letter (because your friend really doesn’t like to read long, complicated things) • T (Topic): What’s the subject or the point of this piece? The point is to explain to your friend how the Taser shotgun shell works…basically, explain to your friend what happened to his body when he was tased. • The Catch: • The letter can only be 20 words or less….giving only the GIST of what your friend needs to know!

11. Elements: • Periodic Table • Basic substances that cannot be broken down into simpler substances • All living and nonliving things are composed of elements • There are 92 naturally occurring elements (think about this…there are only 92 and they make up everything, living and nonliving…pretty cool) • 96% of the human body is composed of just 4 elements: • Carbon (C) Oxygen (O) Hydrogen (H) & Nitrogen (N) • Common Elements in the body (be sure to review) on Page 28, Table 2.1

12. Atoms • An atom is the smallest unit of an element that still retains the chemical and physical properties of an element • Atoms are made up of subatomic particles: • Protons-positive charge • Neutrons-no charge or neutral • Electrons-negative charge • Protons and Neutrons make up the nucleus or core of the atom while Electrons circulate around the core in specific orbital paths • The number of protons an atom has defines what element it is…for example, Carbon always has 6 protons, if it had 7, it would then be Nitrogen! • The number of neutrons can vary and electrons are involved in bonding, so in a sense, their number can vary as well.

13. Isotopes • Isotopes are atoms of the same elements that have different numbers of neutrons • Why do we care in Anatomy?? • Certain isotopes called “radioactive isotopes” undergo decay…as they decay, they emit radiation. Radiation can be detected using a special counter or scanner. • Radioactive isotopes are widely used in biological and medical research….

14. Examples of Radioactive Isotopes in medical/Biological Research: • The thyroid gland uses Iodine (I). It is possible to administer a dose of radioactive iodine and then observe later that the thyroid has taken it up! • Radiation can interfere with cell division in larger doses. Radioisotopes have been used in the treatment of cancer (a disease characterized by uncontrolled cell division). The radiation interferes with cancer cells multiplying. • In your textbook, Page 20, Third Column: PET…also observe picture on Page 21.

15. Bonding: Atom to Atom Interaction • Bonding is all about the electrons… • Ionic: Transfer of electrons that leaves behind charged particles called “ions: • Covalent: Atoms share electrons • Hydrogen Bond: Occurs whenever a H is attracted to an H in another molecule. Very common with water. It is a weak bond that is easily broken • Anatomy Connection: H-bonds help determine 3-dimensional structure of large molecules such as proteins and DNA

16. Chemical Reactions • Chemical reactions involve the making or breaking of bonds between atoms • The total number of atoms remains the same, but the atoms appear in new combinations • Most chemical reactions you need to know for Anatomy have one of the three recognizable patterns described next…

17. Chemical Reaction Types with Anatomy Connections • 1. Synthesis Reactions: • 2 or more atoms or molecules combine to form a larger, more complex molecule • Anatomy Connection: • Synthesis reactions underlie all anabolic (constructive) activities that occur in body cells. They are particularly important for growth and repair of worn out or damaged tissues • Synthesis reactions are necessary for bone development and hair & nail growth.

18. Chemical Reaction Types with Anatomy Connections • 2. Decomposition Reactions: • Occur when a molecule is broken down into smaller molecules, atoms, or ions. • Anatomy Connection: • Decomposition reactions underlie all catabolic (destructive) activities that occur in body cells. • Decomposition reactions are necessary for digestion of foods into their building blocks for our body to use • Also, breakdown of glycogen (a large carbohydrate molecule stored in the liver) to release glucose when blood sugar levels start to decline

19. Chemical Reaction Types with Anatomy Connections • 3. Exchange Reactions: • Involve synthesis and decomposition…Bonds are made and broken. During exchange reactions, a switch is made between molecule parts and different molecules are made. • Anatomy Connection: • This type of reaction occurs in the body when ATP reacts with glucose and transfers its end phosphate group, forming glucose-phosphate. At the same time, the ATP becomes ADP. This important reaction, which occurs whenever glucose enters a body cell, effectively traps the glucose fuel molecule inside the cell for use!

20. Inorganic VS. Organic • All chemicals found in the body fall into one of two major classes of molecules: inorganic or organic • Difference between the 2 is determined solely (with only a few exceptions CO2 and CO) by the presence of Carbon • Inorganic: • Lacks Carbon! Tend to be small, simple molecules • Organic: • Contains Carbon! Are fairly or very large covalently bonded molecules • Both are important and equally essential for life!

21. Inorganic Compounds: 1. Water • Is the single most abundant compound in the body • Acts as a universal solvent in which electrolytes (salts, acids, bases) ionize and in which chemical reactions occur • Is the basis of transport and lubricating fluids • Slowly absorbs and releases heat, thus helping to maintain homeostatic body temperature • Protects certain body structures (such as the brain) by forming a watery cushion

22. Inorganic Compounds: 2. Salts • In ionic form are involved in nerve transmission, muscle contraction, blood clotting, transport of oxygen by hemoglobin, cell permeability, metabolism, and many other reactions. • Additionally, calcium salts (as bone salts) contribute to bone hardness.

23. Inorganic Compounds: 3. Acids • Are proton donors • When dissolved in water, they release Hydrogen ions • Strong acids dissociate (break down) completely in water & weak acids dissociate incompletely in water • Example in body: Hydrochloric acid produced in the stomach aids in digestion

24. Inorganic Compounds: 4. Bases • Are proton acceptors • The most important inorganic bases are hydroxides • Bicarbonate ions are important bases in the body (part of blood). • When bases and acids interact, neutralization occurs-that is, a salt and water are formed.

25. pH Scale: H+ Can be Measured • The pH scale is used to indicate the acidity and basicity (or alkalinity) of a solution. • It is a scale of 0-14 where 7 is neutral and the smaller the number the more acidic and the larger the number the more basic the substance. • As we move down the pH scale, each unit has 10 times the number of H+ ions as the previous unit. • In living things, pH needs to be maintained within a narrow range or there are health consequences. • Norma blood pH ranges from 7.35-7.45. Slight deviations outside this range can be fatal!

26. organic Compounds: 1. Carbohydrates • Contain carbon, hydrogen, and oxygen • Classified according to size as monosaccharides, disaccharides, or polysaccharides • Their building blocks are monosaccharides (these join to form the “di” and “poly”) • Monosaccharides include glucose, fructose, galactose, deoxyribose, and ribose • Disaccharides include sucrose, maltose, and lactose • Polysaccharides include starch and glycogen • Carbohydrates are ingested as sugars and starches • Carbohydrates (in particular glucose) are the major energy sources for the formation of ATP

27. organic Compounds: 2. Lipids • Include triglycerides, phospholipids, and steroids (including cholesterol) • Triglycerides (neutral fats) are found primarily in adipose tissue where they provide insulation and reserve body fuel • Phospholipids and cholesterol are found in all cell membranes. Cholesterol also forms the basis of certain hormones, bile salts, and vitamin D

28. organic Compounds: 3. Proteins • Are constructed from building blocks called amino acids • 20 common types of amino acids are found in the body • Amino acid sequence determines the proteins constructed • Fibrous, or structural proteins are the basic structural materials of the body • Globular proteins are also called functional proteins; examples of these include enzymes, some hormones, and hemoglobin • Disruption of the hydrogen bonds of functional proteins leads to their denaturation and inactivation • Proteins account for over 50% of the organic matter in the body and have the most varied functions

29. organic Compounds: 4. Nucleic Acids • Role is fundamental: they make up genes, which provide the basic blueprint of life…not only do they determine what type of organism you will be, but they also direct your growth and development! • Nucleic Acids include: • Deoxyribonucleic Acid (DNA) which maintains genetic heritage by replicating itself before cell division and contains the code-specifying protein structure • Ribonucleic Acid (RNA) which acts in protein synthesis to ensure that instructions of the DNA are executed

30. organic Compounds: 5. Adenosine Triphosphate ATP • Is the universal energy compound used by all cells of the body • Without ATP, molecules cannot be made or broken down, cells cannot maintain their boundaries, and all life processes grind to a halt! • Although glucose is the most important fuel for body cells, none of the chemical energy contained in its bonds can be sued directly to power cellular work…instead, energy released as glucose is catabolized, captured, and stored in the bonds of ATP molecules as small packets of energy

31. The terrorist attacks on New York City’s world Trade Center killed more than 3,000 people, their bodies buried in millions of tons of rubble. In a situation like this, how can we identify individuals with any certainty? Table Talk: