Key Concepts in Chemistry & Biochemistry

Anything that occupies space and has mass

Matter

Amount of matter in an object

Mass

States of matter relevant to physiology

Solids; liquids; gas

Has defined shape and volume

Solids

Has defined volume; undefined shape

Liquids

Has both undefined shape and volume

Gases

Study of matter and how the building blocks of matter are put together

Chemistry

__ elements required to build a human

24

Makes up 96.1% of body mass

Major elements

Major elements

Oxygen; carbon; hydrogen; nitrogen

Makes up 3.9% of body mass

Minor elements

Sodium; chlorine; calcium; potassium; phosphorus; sulfur; magnesium; iron; iodine

Minor elements

Less than 0.01% of body mass

Trace elements

Copper; zinc; manganese; cobalt; chromium; selenium; molybdenum; fluorine; tin; silicon; vanadium

Trace elements

_____ are building blocks of elements

Atoms

Atoms are composed of ____ types of subatomic particles

3

Subatomic particle with positive electrical charge

Proton

Subatomic particle with no electrical charge

Neutron

Subatomic particle with a negative electrical charge

Electron

Atoms are electrically ______

Neutral

Some atoms gain or lose electrons to become _____

Ions

Atoms that gain a net electrical charge because they gained/lost one or more electrons

Ions

Ion with a net positive charge due to the loss of one or more electrons

Cations

Ion with a net negative charge due to the gain of one or more electrons

Anions

An energy relationship between the electrons of reacting atoms

Chemical bond

Combination of 2 or more atoms held together by chemical bonds

Molecules

The atoms can be all the same elements in a molecule

True

The atoms can be different elements in a molecule

True

Molecules do not range in size

False

Chemical bonds from between chemically reactive elements

True

Chemically reactive elements are stable due to how their electrons are arranged

False

Chemically reactive elements aim to achieve stability by forming chemical bonds

True

3 key types of chemical bonds

Ionic; polar covalent; non-polar covalent

Complete transfer of one or more electrons from one atom to another

Ionic bond

Forms between two atoms that share one or more electrons unequally

Polar covalent bond

Forms between two atoms that share one or more electrons equally

Non-polar covalent bond

Creates anion & cation; opposite charge holds them together

Ionic bond

Creates polarity; one end has slight negative charge; other end has slight positive charge

Polar covalent

Charge is balanced; no polarity

Non-polar covalent bond

Weak—most break when added to water

Ionic bond

Chemical bonds are forms and/or broken by chemical reactions

True

A reaction that forms, breaks, or rearranged chemical bonds

Chemical reaction

Starting substances

Reactants

New substances generated by the reaction

Products

Sum total of all chemical reactions occurring in the body

Metabolism

Reactions that join smaller, simpler reactants together to form larger, more complex products

Anabolic reactions

Energy consuming reactions

Anabolic reactions

Larger, complex reactants are broken down into smaller, less complex products

Catabolic reactions

Energy releasing reactions

Catabolic reactions

A mixture that has exact same composition throughout

Solution

Substance present in greatest amount

Solvent

_____ is the most important solvent in physiology.

Water

Substances dissolved in solvent

Solutes

Amount of a particular solute present per volume of solution

Concentration

Carbon-containing molecules made by living things; held together by covalent bonds; can be huge

Organic molecules

All other molecules; some held by together by covalent bonds; other by ionic bonds; H2O, salts, many acids and bases

Inorganic molecules

______ most abundant inorganic molecule

Water

Water makes up ______ body weight

50-60%

Makes water resistant to changes in temperature

High heat capacity

Allows water to carry lots of excess heat away from body once it evaporates

High heat of vaporization

Dissolves polar and ionic molecules to facilitate chemical reactions and transport

Polar solvent properties

Functions as a reactant in many chemical reactions essential for life

Reactivity

Provides protection from physical trauma

Cushioning

Molecules that releases hydrogen ions when dissolved in water

Acid

Molecule that removes hydrogen ions from solutions

Base

Scale used to measure the free hydrogen ion concentration of a solution

pH scale

Neutral

pH 7

Acidic solution

pH less than 7

Alkaline solution

pH greater than 7

____ forms backbone of all organic molecules

Carbon

Carbohydrates; lipids; proteins; nucleic acid

4 classes of organic molecules

Polymers are assembled from monomers by ___________

Dehydration synthesis

Polymers broken down into monomers by _______

Hydrolysis

3 main subclasses of carbohydrates

Monosaccharides; disaccharides; polysaccharides

Provide a ready, easily used source of energy for all cells

Hexose sugars (6 carbons)

Serve as a structural component of nucleic acids

Pentose sugars (5 carbons)

Polysaccharide consisting of highly branched polymer of glucose; stores energy for future use

Glycogen

Covalent bonds mostly non-polar, therefore insoluble in water

Lipids

3 main subclasses of lipids

Triglycerides; phospholipids; steroids

Glycerol; 3 fatty acids; highly non-polar

Triglycerides (fat)

Stores energy; insulates deep tissue from heat loss; cushions deep tissue

Functions of triglycerides (fat)

1 glycerol; 1 phosphate; 2 fatty acids

Building blocks of Phospholipids

Hydrophilic

Polar head group

Hydrophobic

Non-polar tails

Phospholipid ______ form main lipid component of all cell membranes

Bilayers

Cholesterol

Most important steroid

Structural component of cell membranes

Steroids

Building blocks of proteins

Amino acids

Amino acids are joined by _____

Peptide bonds

Building blocks of nucleic acids

Nucleotides

2 classes of nucleic acids

Deoxyribonucleic acid (DNA); ribonucleic acid (RNA)

3 components of nucleotides

Pentose sugar; nitrogen containing base; a phosphate

Pentose sugar of DNA

Deoxyribose

Purines contain

Adenine (A); Guanine (G)

Pyrimidines contains

Thymine (T): Cytosine (C)

Stores genetic information that specifies the amino acid sequence of all proteins

Deoxyribonucleic acid (DNA)

Pentose sugar of Ribonucleic acid (RNA)

Ribose

Pyrimidines of RNA

Uracil (U); Cytosine (C)

Uses genetic information stored in DNA to build all proteins

Function of RNA