Chapter 2 - Chemical Levels of Organization

Chemistry

the science of structure and interactions of matter

Matter

anything that has mass and takes up space

Mass

the amount of matter that makes up an object, does not chance, measured in daltons

Weight

the force of gravity acting on mass

How matter is organized

• exists in three forms: solid, liquid, gas

• all forms of matter are composed of chemical elements

The human body is composed of __ different elements

26

Four major Elements in Body (96%)

oxygen, carbon, hydrogen, nitrogen

Eight Lesser Elements in Body (3.6%)

Ca, P, K, S, Na, Cl, Mg, Fe

Fourteen Trace Elements in Body make up __%

0,4

Structure of Atoms

protons, electrons, neutrons

Atom definition

smallest units of matter that retain the properties and characteristics of an element

Protons

positively charged, also atomic number

Neurons

no charge, determine if an istope of a certain element, add mass

Electrons

negatively charged

Atomic mass

the average mass of the all its naturally occuring isotopes

Mass number

the sum of protons and neutrons in an atom and indicates how much gravity acts on the atoms (always a whole number)

Masses of Subatomic Particles in Daltons

Proton: 1.007 Daltons

Neuron: 1.008 Daltons

Electron: 0.0005 Daltons

Molecules

formed when there are interactions between the electrons of two or more atoms

Compound

a substance that can be broken down into two or more different elements

Ions

atoms that have given up or gained an electron to its outer shell, have an uneven amount of protons and electrons

Free Radical

electrically charged atom or group of atoms with an unpaired electron in its outer shell, unstable and highly reactive

Antioxidants

substances that inactivate oxygen-derived free radicals

Chemical Bonds

occurs when atoms of a molecule or compound are held together by forces of attraction

Ionic Bonds

forms when an atom loses or gains a valence electron

Cations

positively charged ions that have given up one or more electrons

Anions

negatively charged ions that have picked up one or more electrons

Electrolyte

ionic compound that splits into positive and negative ions in solutions

Covalent Bonds

formed by the atoms and molecules sharing 1,2, or 3 pairs of valence electrons

most common chemical bond in human body

Non-Polar

atoms share the electrons equally, most common

Polar

formed by the unequal sharing of electrons between atoms, forms water molecules

Hydrogen Bonds

weak interactions between hydrogen and adjacent electronegative atoms

result from attraction between partially positive hydrogen and partially negative atoms that are different atoms

bonding provides cohesion which creates high surface tension

Chemical Reactions Definition

occur when bonds between atoms or molecules are formed or broken

Metabolism

the sum of all the chemical reactions in the body

Reactants

materials that are present at the start of a chemical reaction

Products

substances at the end of the chemical reaction

Law of Conservation of energy

the total mass of reactants equals the total mass of the products

Kinetic Energy

energy of matter in motion

Chemical Energy

energy stored in chemical bonds

Potential Energy

energy stored due to an objects position

Exergonic Reactions

release more energy than they absorb by breaking a bond with more energy than the one being formed

Endergonic Reactions

require energy be added to form a bond

Activation Energy

energy required to break chemical bonds in the reactant molecules so a reaction can start when the molecules collide

Factors that cause a collision

• temperature

• concentration of reactants

• presence of absence of a catalyst

Catalyst

• chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur

• can neither be consumed nor produced in the reaction and can be reused until they are broken down or removed

Concentration

increased by adding more particles present or increasing temp

when temp is increased the speed of the moving particles increases

Types of Chemical Reactions

• synthesis

• decomposition

• exchange

• reversible

Synthesis Reactions

anabolism (ex: building proteins from amino acids)

Decomposition Reactions

catabolism (ex: sucrose degraded to glucose + fructose)

Exchange Reactions

ex: H2O + CO2 (with a catalyst) forms H + HCO

Reduction Reactions

breaks down food molecules to produce energy

Oxidation

loss of electrons and in the process the oxidized substance releases energy

Reduction

gain of electrons and in the process the reduced substance gains energy

Inorganic Compounds Definition

structurally simple molecules that usually lack carbon

consist of water, salts, acids, and bases

Water Characteristics

polarity

is a solvent

often acts as a lubricant

sticky

high surface tension due to weak hydrogen bonds

Water has a ___ heat capacity

high

Water can ___ or ____ a relatively large amount of heat

absorb, release

Heat of Vaporization

amount of heat needed to change from a liquid to gas is high

Hydrophilic

substances which contain polar covalent bonds and dissolve in water, are charged

Hydrophobic

substances which contain non-polar covalent bonds

Dehydration Synthesis Reaction

occurs when two small molecules combine to form one large molecule and one water molecule

Hydrolysis

to loosen or break apart molecules with the addition of water

Organic Compounds Definition

always contain carbon and are usually large, complex molecules, usually contain hydrogen, always have covalent bonds

Organic Compounds Create

• carbohydrates

• lipids

• proteins

• nucleic acids

• adenosine triphosphate (ATP)

Functional Groups

found attached to the carbon skeleton, have characteristics components and impart certain properties

Isomers

have some molecular formulas but different structures

Macromolecules

very large, can be any of the products created of organic molecules

Carbohydrates characteristics

• provide most of the chemical energy needed for life (sugars, starches, glycogen, cellulose)

• made of carbon, oxygen, hydrogen

Carbohydrates: Monosaccharides

• glucose, fructose, galactose

• simple sugars

• 5 carbon sugars are used in nucleic acids

Carbohydrates: Disaccharides

• made by combining two monosaccharides by removing a water molecule(dehydration synthesis)

Sucrose = what products

glucose and fructose

Lactose = what products

glucose and galactose

Carbohydrates: Polysaccharides

• largest carbs

• glycogen is the most common in human body

Lipids characteristics

• contains carbon, hydrogen, oxygen

• hydrophobic and mostly insoluble in water because they lack polar covalent bonds

For Lipids to become water soluble, they form ____ and explain

Lipoproteins

lipid combines with an amphioathic protein molecules

Fatty Acids

• simplest lipid

• building blocks of triglycerides and phospholipids

• consist of a carboxyl group and a hydrocarbon chain

Saturated Fatty Acids

contain single covalent bonds between adjacent carbon atoms

Unsaturated Fatty Acids

contain carbon that is not completely saturated with hydrogen atoms

Lipids: Triglycerides

provide protection, insulation, and energy

contain one glycerol to three fatty acids

Triglycerides are produced by ….

dehydration synthesis and can be reduced through hydrolysis

Triglyceride storage is unlimited as it is efficient..

storage of energy for later use, twice as much energy per gram than proteins or carbs

Triglycerides are the ___ concentrated form of ____ energy

most, chemical

Brain ____ use lipids

cannot

Lipids: Phospholipids

• important cell membrane component

• amphipathics

• have polar head and two non-polar fatty tails

Amphipathic

contain both polar and non-polar regions make them soluble in both water and fats

Lipids: Steriods

• have four rings of carbon atoms

• can comes in forms such as cholesterol, hormones, bile salts, vit d, and eiocosanoids

Cholesterol

serves as important component of cell membranes and as starting material for synthesizing other steriods

Hormones

including cortisol and sex hormones

Proteins characteristics

• large molecules

• contain carbon, hydrogen, oxygen, and nitrogen

• constructed from combinations of amino acids

Amino Acid

have same basic structure - central carbon with four bonds (hydrogen, amino group, acid group, R group changes)

Dipeptides

formed from two amino acids joined by a covalent bond (peptide bond)

involves dehydration synthesis, hydrolysis of the peptide bond can release amino acids

Polypeptide Chains

contains 10-2000 amino acids, protein structure and function is determined by amino acid sequence and final shape of protein

Protein Structure Organization

• primary

• secondary

• tertiary

• quaternary

Protein Structure Organization: Primary

gives the unique sequence of AA, genetically determined

Protein Structure Organization: Secondary

the repeated twisting and folding of primary sequence, alpha helix and beta pleated sheets between non-sequencial R groups

Protein Structure Organization: Tertiary

3-d shape from folding of secondary level, from bonds between non-adjacent amino acids

Protein Structure Organization: Quaternary

arrangement of individual ploypeptide chains in proteins containing more than one polypeptide

Shape generally influences its ability to ____ and bind to other molecules and be functional

recognize

Desaturation

loss of protein structure

loss of protein characteristic shape and function, conditions outside of homeostatic ranges can cause this

Protein: Enzymes characteristics

• catalyze metabolic reactions in all living cells

• enzymes has effect on the substrates