A and P: Chapter 2

state the four most abundant elements in the body

Oxygen, carbon, hydrogen, and nitrogen

anything that occupies space and has mass

matter

simplest type of matter with unique chemical properties

elements

smallest PARTICLE of an element that have the characteristics of that element

atoms

Name the subatomic particles of an atom, and indicate their mass, charge, and location in an atom

Proton: Mass of 1 AMU, +1 charge, located inside the nucleus

Neutron: Mass of 1 AMU, no charge = neutral, located in the nucleus

Electron: Mass of 1/200 AMU, -1 charge, located in the electron cloud

Define atomic number

The number of protons in the nucleus of an atom

Define mass number

The number of protons plus the number of neutrons in an atom

Two or more forms of the same element that have the same number of protons but a different number of neutrons

isotopes

occurs when the outermost electrons of an atom are transferred or share between atoms

chemical bonding

Form from the transfer of an electron from one atom to another

ionic bonds

Form when atoms share one or more pairs of electrons

Covalent bonds

Types of covalent bonds

Polar: electrons are shared unequally between atoms

• The nucleus of one atom

  attracts electrons more

  strongly than does the

  nucleus of the other atom.

Nonpolar: electrons are shared equally between atoms

• Atoms have similar

  electronegativities.

Positively charged ion formed by losing electrons

cation

Negatively charged ion formed by gaining electrons

anion

Two or more atoms chemically combine to form a structure that acts as an independent unit

molecule

Substance resulting from the chemical combination of two or more different types of atoms

compound

What creates a hydrogen bond

A positively charged hydrogen (H) of one molecule is attracted to the negatively charged oxygen (O), nitrogen (N), or fluorine (F) of another molecule

Hydrogen bond importance and strength

Determining the shape of molecules is important because the bonds hold the molecules in their normal 3D shape

Ability of one substance to dissolve in another

solubility

When ionic compounds dissolve in water, their ions separate from each other

dissociation

Cations and anions that dissociate in water

electrolyte

chemical reactions occur when bonds between atoms, ions, molecules, or compounds are

formed, rearranged, broken

Chemical combination of two or more reactants to form a larger, more complex product

Ex: A + B = AB

synthesis

decomposition

A larger reactant that is chemically broken down into two or more smaller substances

Ex: AB = A + B

All synthesis reactions that occur within the body

anabolism

Decomposition reactions that occur within the body.

catabolism

Explain how reversible reactions produce chemical equilibrium

When the rate of the forward reaction becomes equal to the rate of the reverse reaction

stored energy that could do work

Potential energy

energy that actually does work

kinetic energy

Reactions that result from the exchange of electrons between the reactants

oxidation and reduction

loss of an electron by an atom

oxidation

gain of an electron by an atom

reduction

Describe the law of conservation of energy

Total energy is constant, energy is neither created nor destroyed, one type of energy can be changed into another

Energy resulting from the position or movement of objects

mechanical energy

potential energy stored in the chemical bonds of substances

chemical energy

Energy that flows between objects that are different temperatures

heat energy

Distinguish between chemical reactions that release energy and those that take in energy

Release energy- Breakdown of ATP

Take in energy- Synthesis of ATP

If potential energy in the chemical bonds of the reactants is greater than that of the products, the reaction _____

releases energy (breakdown of ATP)

If potential energy in the chemical bonds of the reactant is less than that of the products _____

energy must be added for the reaction to occur (synthesis of ATP)

Minimum amount of energy that reactants must have in

order to start a chemical reaction

activation energy

Describe the factors that can affect the rate of chemical reactions

Catalysts increase the rate of a chemical reaction without being permanently changed or depleted.

Ex. enzymes - proteins that decrease activation energy required for reaction to proceed

temperature - increased temp increases the likelihood of chemical reaction, and concentration of reactants - increases the likelihood of two reactants coming into contact with one another.

Describe how the properties of water contribute to its physiological functions

Body Temp: high heat capacity allows it to absorb and release large amounts of heat before changing body temperature

• blood can transfer heat from deep within the body to the body’s surface to be released

Chemical reactions: most chemical reactions necessary for life don't take place unless the reacting molecules are dissolved in water

Protection: acts as a lubricant or cushion to protect the body's organs from damage

• ex: tears for eyes

Transport: polar solvent properties, dissolves ionic substances, forms hydration layers, serves as the body's major transport medium

• Blood transports nutrients, hormones, gases, and wastes throughout the body

Mixing Medium

• combination of two or more substances physically blended together but not chemically combined

Describe the pH scale and its relationship to acidic, basic, and neutral solutions

pH scale indicates the H+ concentration in a solution

Acidic: greater concentration of H+ than OH-, pH < 7

Basic (alkaline): lower concentration of H+ than OH-, pH > 7

Neutral: equal number of H+ and OH-, pH = 7

Define alkalosis

Nervous system becomes over-excitable if blood pH rises above 7.45

Define acidosis

Nervous system becomes depressed if blood pH drops below 7.35

Set point for human blood

7.4 pH

Normal range for human blood

7.35 - 7.45 pH

Compounds consisting of a cation other than H+ and anion other than OH-

salts

resist change in solution pH when either an acid or base is added to the solution

Essential for maintaining a stable, internal pH

buffers

Compare the roles of oxygen, carbon dioxide, and water in the body

Oxygen is required by humans for the extraction of energy from food molecules, carbon dioxide is produced from the breakdown of food molecules, and water helps stabilize body temperature and protects the body's organs from damage, chemical reactions, transport, and mixing medium

Primarily concerned with non-carbon-containing substances

inorganic chemistry

Concerned with substances that contain carbon.

organic chemistry

Explain how enzymes work

Protein catalysts that increase the rate at which a chemical reaction proceeds without the enzyme being permanently damaged, work by lowering the activation energy requirement--> make it easier for chemical reaction to take place

• Enzymes bind to reactants according to the lock-and-key model

  • By bringing the two reactants close to each other it reduces the activation energy for the reaction

carbohydrates

• composed of carbon, oxygen, and hydrogen

• primarily used for energy —> can be broken down to generate ATP

• types:

  • monosaccharides- one sugar (glucose- moves nutrients into body cells)

  • disaccharides - two sugars (sucrose)

  • polysaccharides- many sugars (glycogen)

lipids

• composed of carbon, hydrogen, and oxygen

• energy source, protection/insulation, regulation, structure, vitamins, energy

fats and fatty acids (lipids)

fats: energy source, three fatty acids bound to glycerol

fatty acids:

• Saturated: Contain only single covalent bonds between the carbons

• Unsaturated: Contain one or more double covalent bonds between carbons

lipid types

• Phospholipids:

  • Chief structural components of cell membranes

• Eicosanoids

  • Chemicals derived from fatty acids that regulate physiological processes

• Steroids

  • Include: cholesterol, bile salts, estrogen/progesterone, testosterone

• Fat- soluble vitamins

  • Stored in the liver and fatty tissues, and utilized when needed

proteins

• Contain carbon, hydrogen, oxygen, and nitrogen bound together by covalent (peptide) bonds

• Regulate body processes, muscular contraction, transportation, structure, energy

amino acids 4 components

amine group, carboxyl group, hydrogen atom, side chain

nucleic acids

• Large molecules composed of carbon, hydrogen, nitrogen, and phosphorous

• DNA and RNA

• Nucleotides:

  • Building blocks of DNA/RNA