Chapter 2 - Chemistry Flashcards
Matter
Anything that takes up space and has mass.
Matter is composed of elements. Solids, liquids, and
gases are matter
Mass
Amount of matter present
Weight
Heaviness due to gravitational pull on mass
Chemistry
Studies composition, properties, interaction
of matter
Biochemistry
Biological chemistry, which studies
physiological process and disease
Elements
Simplest types of matter with certain chemical
properties. There are 92 naturally occurring elements
Compounds
Chemical combinations of different elements
Atoms
Smallest particles of an element that have properties
of that element
Bulk elements:
Required by the body in large amounts
(C,O,H,N,S,P)
Trace elements:
Required by the body in small amounts
(Fe,I)
Ultratrace elements:
Required by the body in very minute
amounts (As)
Atoms
composed of subatomic particles
Protons
large particles
carry a single positive charge
Neutrons
Large particles
carry NO electrical charge
Electrons
Small particles
carry a single negative charge
Atoms consists of a ______ _______ (protons + Neutrons) and _______ in constant motion around the nucleus
Central Nucleus
Electrons
Number of _____ equals number of ______ in a atom; therefore, atoms are electrically _____
Protons
Electrons
Neutral
Atomic Number:
Number of protons in the nucleus of an atom of a specific
element
Each element has a unique atomic number
Mass Number:
The number of protons plus the number of neutrons in one
atom
Electrons do not contribute to the mass of the atom
because they are so light
Molecule
Particle formed when two or more atoms
chemically combine
Compound
Particle formed when two or more atoms of
different elements chemically combine
Molecular formulas:
Depict the elements present and the
number of each atom present in the molecule
H2 = a molecule of hydrogen
C6H12O6 = a molecule of glucose
H2O = a molecule of water
Chemical bonds
form when atoms
combine with other atoms. They result
from interactions between the electrons
of the atoms.
Electrons of an atom occupy regions of
space called
electron shells - these encircle the nucleus
For atoms with atomic numbers of 18 or
less, the following rules apply:
- The first shell can hold up to 2
electrons. - The second shell can hold up to 8
electrons. - The third shell can hold up to 8
electrons
Electrons in outermost shell determine
whether atom will react with other atoms
to form chemical bonds
Ion
An electrically charged atom that gains or loses
electrons to become stable
Cation
A positively charged ion, formed when an atom
loses electrons
Anion
A negatively charged ion, formed when an atom
gains electrons
Ionic Bonds:
Strong chemical bonds formed when ions of
opposite charge attract
Covalent Bonds
Strong chemical bonds, formed between
atoms that share electrons
Two atoms of hydrogen (H) can combine to form
a
hydrogen molecule (H2). Both atoms in the molecule
become stable
Hydrogen molecules (H2) often combine with oxygen (O2)
molecules to form
water molecules (H2O)
Nonpolar covalent bonds:
Covalent bonds in which electrons are shared equally
Found between atoms with same electronegativity
Atoms of same element have same number of protons, and
pull shared electrons equally
Polar covalent bonds:
Covalent bonds in which electrons are not shared equally
Found between atoms with different electronegativities
Forms polar molecules with unequal charge distribution
Atoms with larger number of protons have higher
electronegativity, and pull shared electrons closer to their
nucleus
Water is a polar molecule
Hydrogen bonds:
- Relatively weak attraction
of slightly positive (H) end
of one polar molecule to
slightly negative (N or O)
end of a nearby polar
molecule - Form between adjacent
water molecules - Important for protein and
nucleic acid structure
Chemical reactions
occur when chemical bonds form or
break between atoms, ions, or molecules
Reactants
are the starting materials of a chemical
reaction: the atoms, ions, or molecules
Products
are substances formed at the end of the
chemical reaction
Synthesis Reaction
more complex chemical structure is
formed
A + B => AB
Decomposition Reaction
chemical bonds are broken to
form a simpler chemical structure
AB => A + B
Exchange Reaction
chemical bonds are broken and new
bonds are formed
AB + CD => AD + CB
Reversible Reaction
: the products can change back to the reaction
A + B = AB
Electrolytes
Substances that release ions in water. The
solution can conduct an electric current, so it is called an
electrolyte
NaCl => Na plus + Cl negative
Acids
Electrolytes that dissociate to release hydrogen ions
in water
Bases
Substances that release ions that can combine with
hydrogen ions
Salts
Electrolytes formed by the reaction between an acid
and a base
pH Scale
Indicates the concentration of hydrogen ions in a
solution
Neutral
A pH of 7 indicates equal concentrations of
This is the pH of water.
Acidic
A p H of <7 indicates a greater concentration of
Basic (alkaline)
A pH >7 indicates a higher concentration of
What is the normal range of blood?
7.35 through 7.45
Acidemia occurs when blood pH drops to what?
7.0 through 7.3
Acidosis makes a person feel?
disoriented and fatigued
Caused by vomiting of alkaline intestinal contents, diabetes, lung
disease with impaired CO2 exhalation
Alkalemia occurs when blood pH rises to
7.5 through 7.8
Alkalosis makes a person feel
Dizzy and agitated
Caused by high altitude breathing, vomiting of acidic stomach
contents, high fever, taking excess antacids.
Homeostatic mechanisms help regulate pH
Organic molecules:
- Contain C and H
- Depending on the type, they will dissolve in either water or organic
liquids - Water-soluble organic compounds do not release ions, and are non-
electrolytes - Carbohydrates, proteins, lipids, and nucleic acids
Inorganic molecules
- Generally do not contain C and H
- Usually dissolve in water and dissociate, forming ions, and are
electrolytes - Water, oxygen, carbon dioxide, and inorganic salts
Water
- Most abundant compound in living material
- Two-thirds of the weight of an adult human
- Major component of all body fluids
- Medium for most metabolic reactions
- Important role in transporting chemicals in the body
- Absorbs and transports heat
- Water balance exists when gains equal losses
- Water is a solvent that many solutes dissolve in
Oxygen
- Used by organelles to release energy from nutrients in order to
drive cell’s metabolic activities. - Necessary for survival
Carbon dioxide (CO2)
- Waste product released during metabolic reactions
- Must be removed from the body through exhaling
Inorganic salts:
- Abundant in body fluids
- Sources of necessary ions
- Play important roles in metabolism
- Help control H2O concentration, pH, blood clotting, nerve
and muscle processes - Electrolyte balance exists when gains equal losses
Main source of cellular energy:
- Supply materials to build cell structures
- Water-soluble
- Contain C, H, and O
- Ratio of H to O close to 2:1 (C6H12O6 = glucose)
Size classification of carbohydrates:
Monosaccharides
Disaccharides
Polysaccharides
Monosaccharides are…?
(single sugars): glucose, fructose
Disaccharides
(double sugars): sucrose, lactose
Polysaccharides
(complex carbohydrates): starch,
glycogen, cellulose
Lipids
- Insoluble in water, but soluble in organic solvents
- Include triglycerides (fats), phospholipids, steroids
- Important component of cell membranes, and have several
functions in cell
Most abundant lipids are triglycerides (fats)
- Used for cellular energy
- Contain more energy per gram than carbohydrates
- Contain C, H, and O, but less O than carbohydrates
- Consist of 1 molecule of glycerol and 3 fatty acids
Phospholipids
are similar to triglycerides, except that they
have glycerol, 2 fatty acids, and a phosphate group
Saturated fatty acids
Have only single carbon-carbon bonds
* Most are solid at room temperature
* Most are of animal origin
Unsaturated fatty acids
Have one or more carbon-carbon double bond
* Most are liquid at room temperature
* Most are of plant origin
Phospholipids
Similar to triglycerides, except that they have glycerol, 2
fatty acids, and a phosphate group
* Main structural component of cell membranes
Steroids
- 4 connected rings of carbon
- Widely distributed in the body, various functions
- Component of cell membranes
- Used to synthesize adrenal and sex hormones
- Cholesterol is the main steroid in the body
Proteins
- Used as structural materials, energy source, hormones,
receptors, enzymes, antibodies - Consist of building blocks called amino acids
- An amino acid contains an amino (–NH2) group, a carboxyl
- (COOH) group, and a unique R (side chain) group
- Amino acids are bound to each other by peptide bonds
Peptide bonds
form between the amino group of one
amino acid, and the carboxyl group of the adjacent amino
acid
4 Levels of Protein Structure:
Primary
Secondary
Tertiary
Quaternary
Primary
Amino acid sequence
Secondary
Pleated or twisted structure formed by hydrogen bonding
between nonadjacent amino acids
Tertiary
Unique 3-dimensional folded shape, or conformation, of the
protein, which determines its function
Quaternary
Structure formed by some proteins, when 2 or more
polypeptide chains are connected to become 1 protein
Denaturation
- A change in the secondary and tertiary structure of a protein
- Caused by heat, radiation, pH changes, chemicals
- Sometimes reversible, and other times irreversible
- In case of enzymes, irreversible denaturation stops it from functioning
Nucleic acids:
- Carry genetic code (DNA) or aid in protein synthesis (RNA)
- Nucleic acids encode amino acid sequences of proteins
- Building blocks are called nucleotides, which consist of a
sugar (S), a phosphate group (P), and an organic base (B)
DNA
(Deoxyribonucleic acid): a double chain of nucleotides
RNA
(Ribonucleic acid): a single chain of nucleotides
What are two major types of Nucleic Acids
DNA and RNA
DNA
- Stores the genetic code
- Contains the sugar deoxyribose
- Structure—double helix
- Composed of nucleotides
RNA
- Interacts with DNA to conduct protein synthesis
- Contains the sugar ribose
- Structure—single stranded
- Composed of nucleotides
