Anatomy & Physiology 34A Lecture
Chapter 2 – Chemistry Comes Alive: Biochemistry
I. Overview
A. Inorganic Compounds
1. Water
2. Salts
3. Acids, Bases & pH
B. Organic Molecules
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
II. Inorganic Compounds
A. ________ - the body is composed of about 60% water, which has important functions
1. _________ (hydrophilic) molecules and salts dissolve in water, the universal
__________
a. The degree to which a molecule dissolves is its ___________
b. The more readily a molecule ____________, the higher its solubility
2. ___________ (hydrophobic) molecules (e.g., _________) do not dissolve in water
3. Water’s surface ___________ is important in lung function
4. Water’s high heat ___________ (amount of heat needed to raise the temperature of 1
gram of water by 1C = 1cal/g) prevents sudden changes in body temp.
5. Water’s high heat of _____________ allows sweat to evaporate and cool the body
6. Water’s ____________ facilitates dehydration synthesis and hydrolysis chemical
reactions.
B. __________ (electrolytes) are molecules that ionize in water to form solutions that can
conduct electricity.
1. Important human __________________ include: Na+, Cl-, K+, Ca2+, Mg2+, PO43-, and
HCO32. Electrolytes are essential for __________ and muscle function
C. Acids, Bases, & pH
1. Liquid water dissociates into equal numbers of ___ & ____ ions, in addition to a
majority of H2O molecules (e.g.: H2O  H+ + -OH)
2. _________ - dissociate in water and release ___ ions (protons) (e.g.: HCl  H+ + Cl-);
the more H+ ions released, the _______ the acid
3. ________ - dissociate in water and take up ____ ions or release _____ (hydroxide)
ions (e.g.: NaOH  Na+ + -OH)
4. The pH _________ is used to measure acidity and basicity
a. _____ number indicates degree of acidity or basicity of solution
b. pH = power of __________ - the negative logarithm of the hydrogen ion
concentration of a solution (pH 3 = -log 3 [H+] = 10-3 M H+). pH is an
_____________ scale of H+ concentration
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c. Acid is ______ than pH 7; the lower the number, the more ____, the more acidic. A
decrease of 1 pH increases acidity ____ fold
d. Neutral is pH ___. In pure water (pH7) H+ = -OH
e. Base is _______ than pH 7; the higher the number, the less ___, the more basic. An
increase of 1 pH increases basicity ___ fold
5. Blood pH must be maintained within _____-______ pH.
a. H+ ion concentrations lower or higher than this range can interfere with
___________ bonding and Van der Waals forces holding organic molecules together
6. ____________ - chemicals that take up excess H+ or -OH ions and keep the pH
constant
a. Example: carbon dioxide and water in the blood combine to form weak
___________ _______, which dissociates into hydrogen ions and bicarbonate ions.
The ______________ is a buffer that can take up excess H+ ions.
(CO2 + H2O ↔ H2CO3  H+ + HCO3-)
III. ____________molecules compose living (or previously living) things
A. ___________ molecules always contain carbon and hydrogen
1.
_______ has 4 electrons in its outer shell, therefore can form up to ___ covalent
bonds with other atoms (i.e., H, O, N, S)
2. This property allows carbon to become the ____________ of organic molecules
3. Functional groups, such as carboxyl (-________ = acid) and hydroxyl (-____ =
base), methyl (-____), amine (-____), and phosphate (-______) can be bonded to
carbon groups
B. Four classes of organic ____________ are: carbohydrates, lipids, proteins, and
nucleic acids
IV. ______________ – hydrophilic molecules that contain C, H, and O in a ratio of about 1C:2-H:1-O; function: primary ________ source & structural role in cells. (Energy = ___
kcal/gram)
A. ______saccharides - simple sugars with 3-7 carbon atoms in [CH2O]n form; the basic
____________ blocks of carbohydrates. pentose sugars have ___ carbons, hexose sugars
have ___ carbons.
1. _________ (C6H12O6) - primary energy source for cells (______ sugar)
2. __________ (C6H12O6) - ___________ sugar
3. ______________ (C6H12O6) - _________ sugar
B. ____saccharides - two ________saccharides bond together
1. ____________ - glucose + fructose
2. ____________ - glucose + glucose
3. ____________ - glucose + galactose
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C. ________saccharides - polymers of many monosaccharides (usually __________
molecules) covalently bonded together
1. ___________ - storage form of glucose in animals; stored in our ______ and muscle
cells, broken down to glucose when needed
2. __________ - storage form of glucose in plants; stored in starch granules in plant
cells, digested to __________ in our bodies
3. ___________ - main component of plant cell walls; also known as _________; we
can’t digest this because the covalent bonds between the glucose molecule are slightly
different than those in starch and glycogen
4. Most carbohydrates are broken down to __________, which is used in cellular
respiration to produce _______ energy
V. _________ - molecules composed of CHO in a variable ratio; functions: long-term
_________ storage, adipose tissue insulates and cushions organs. (Energy = ___ kcal/gram)
Lipids are ___________, do not mix with water. Types of lipids include:
A. ________ ________ - hydrocarbon chain with carboxylic acid group at one end and a
methyl group at the other end
1. ____________ - have no double bonds between carbons; _____________ fats,
mostly from animal sources and hydrogenated plant oils; _________ at room
temp.
2. ____________ - have one or more double bonds between carbons;
__________ oils, from plant sources, _________ at room temp.
B. _______________ - three fatty acids bonded to one ___________; nonpolar molecule;
excess in blood contributes to heart disease
C. __________lipid - two fatty acids (nonpolar) and a ___________ group (polar) bonded
to one glycerol; found in ______ membranes
D. ________ - have a backbone of 4 fused carbon rings with different functional groups;
includes cholesterol and several hormones
1. _______________ - manufactured in animal ________, used in cell membranes, bile,
and steroid hormones. Circulates in the blood in two main forms:
a. _______ (Low Density Lipoprotein) - “_____” cholesterol, excess in blood clogs
arteries
b. _______ (High Density Lipoprotein) - “_______” cholesterol, recycles
cholesterol back to liver
2. ______________ hormones include the ______ hormones estrogen, progesterone, and
testosterone
E. ______________ are 20 carbon compounds derived from the fatty acid arachadonic acid
1. Include leukotrienes, thromboxanes, and _________________
2. These are _____________ molecules in inflammation, blood clotting, and control of
blood vessel diameter
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VI. __________ - large organic molecules consisting of chains of 50 or more amino acids
composed of carbon, hydrogen, oxygen, ________, and sometimes sulfur. (Energy = ___
kcal/gram)
A. Structural proteins - give strength and shape to different tissues (e.g.: keratin in hair &
nails, collagen in connective tissues, _________ proteins, etc.)
B. Functional proteins - such as __________, hormones, membrane proteins, antibodies,
etc., are proteins that facilitate metabolic reactions.
C. _________ ________ - basic building blocks of proteins; there are ___ different amino
acids, each of which has the following bonded to a central ________ atom (see book for
the 20 amino acid names)
1. Amine group (-_____)
2. Carboxylic acid group (-______)
3. Variable “___” (radical) group; some “R” groups are _______ (hydrophilic), and some
are ____________ (hydrophobic)
4. ____________ atom
D. Amino acids may be ___________ or nonessential
1. Nonessential AAs are the ____ that are synthesized by the body
2. Essential AAs are the ____ that cannot be synthesized by the body, thus must be
obtained by eating complete proteins
E. Peptide – two to nine amino acids linked together by __________ ________, formed
between the amine group of one amino acid and the carboxyl group of another (HOOCNH2)
1. ______________ – 10-50 bonded amino acids
2. ____________ – polypeptide of more than 50 amino acids
F. Levels of Protein Organization
1. __________ Structure - linear sequence of amino acids bonded together. All
polypeptides have specific amino acid _________
2. ___________ Structure - twisting or folding of the polypeptide chain (e.g.: alpha
________ or beta-pleated sheet), formed by hydrogen bonding between negative C=O
and positive N-H
3. ___________ Structure – folding and coiling of a polypeptide (e.g.: to _________ or
___________) due to interactions among R groups and surrounding water
4. _______________ Structure – association of ___ or more polypeptide chains
together (e.g.: hemoglobin has 4 polypeptide chains)
5. Proteins must _______ into precise shapes to function properly
6. Proteins, such as enzymes, can be ______________ (nonfunctional shape change) by
heat or strong pH
G. Proteins, lipids, and carbohydrates can combine to form ______proteins, glycolipids, or
______proteins
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VII. Nucleic Acids - include DNA, RNA, and ATP; functions include cellular reproduction
(_____), protein manufacturing instructions (DNA & ______), and cellular energy source
(____)
A. _____________ - basic building block of nucleic acids; composed of a phosphate group,
a pentose sugar, and a nitrogenous base
B. ______ (Deoxyribonucleic Acid)
1. Found in ________________, mostly in the cell nucleus
2. Forms _______ (specific sequences of DNA) that regulate the growth & reproduction
of cells and direct the order in which amino acids are put together to form
___________
3. DNA is a double-stranded _________ (like a twisted ladder) held together by
hydrogen bonds and is composed of:
a. ______________ sugar and ____________ groups form the side rails of the
“ladder”
b. Nitrogenous _______ held together by __________ bonds form the ladder steps.
These bases include:
1) Thymine (__) 2) Adenine (__)
3) Cytosine (__)
4) Guanine (__)
C. ______ (Ribonucleic Acid)
1. Works with DNA for __________ synthesis
2. Is mostly a __________-stranded molecule
3. Has __________ sugar
4. Has the same nitrogenous bases as DNA, except it has __________ instead of
thymine
D. _____ (Adenosine Triphosphate)
1. Is a nucleotide composed of _________, a ribose sugar, and 3 ___________
groups held together with high energy bonds
2. ATP is formed via the process of cellular _________, during which glucose bond
energy is transferred to ATP bonds
3. Functions as the main ________ source in cells due to energy in the phosphate
bonds
4. Other molecules related to _____ include cAMP, NAD+, and FADH
a. cAMP is a cell ____________ molecule
b. NAD+ & FADH are _______ transfer molecules in cell respiration