1. Biology 211 Anatomy & Physiology I
Macromolecules of Importance in Human Anatomy & Physiology

2. Many molecules in the human body are very large, consisting of hundreds or even thousands of atoms.
These are called macromolecules.
Four types of macromolecules are particularly important in the human body:
Proteins
Carbohydrates / Polysaccharides
Lipids
Nucleic Acids

3. All of these macromolecules are polymers which consist of repeating smaller subunits called monomers
Polymer: Monomers
Protein Amino acids
Carbohydrate/ Monosaccharides
Polysaccharide
Lipid Fatty acids & Glycerol
Nucleic Acid Nucleotides

4. Rather than draw out these large molecules, we typically use a set of shorthand figures for them
Amino acids are usually shown as circles
Monsaccharides are usually shown as polygons showing the number of carbons
Fatty acids are usually shown as wavy lines
Nucleotides are usually shown with three parts

7. Polymer: Monomers:
Protein Amino acids

8. Some important functions of proteins in the human body:
Membrane Proteins
Enzymes
Structural proteins
Some Hormones
Antibodies
Contractile Proteins
Blood Clotting

9. Proteins are composed of unbranching chains of amino acids arranged in different sequences. There are different amino acids, all of which have the same basic structure:
Where "R" is different for each amino acid

13. Glycine - Alanine - Glutamine - Alanine – Serine – Lysine -Valine and
The sequence of amino acids in a protein is called its primary structure
Thus, the proteins
Glycine - Alanine - Glutamine - Alanine – Serine – Lysine -Valine
and
Alanine – Valine - Alanine - Glycine – Lysine - Serine - Glutamine
have different primary structures even though they contain the same seven amino acids
(Scientists are lazy: Amino acids are
often shown as circles instead of
drawing out all the atoms)

14. The chain of amino acids in a protein will fold into specific patterns, called its secondary structure
Different parts of each chain fold in different ways;
Thus, they have different secondary structures

15. This folded protein folds even further to form its tertiary structure
Since proteins with different primary structures will fold into different secondary structures, they will also fold into different tertiary structures

16. Obviously, proteins with different primary structures
These folded proteins may group together, providing the protein with its quaternary structure.
Obviously, proteins with different primary structures
will have different secondary structures
and thus different tertiary structures
which will group into different quaternary structures
Hemoglobin
Immunoglobulin (antibody)

17. The specific function of any protein depends on its three-dimensional shape (secondary, tertiary, and quaternary structures)
If the shape of the protein is changed, it will no longer function as it should.
This is called denaturing the protein

18. Polymer: Monomers:
Protein Amino acids
Carbohydrate Monosaccharides

19. Different monosaccharides have different structures, but all share the same basic formula: Cn H2n On
Most common monosaccharides: C6 H12 O6
Also found: C3 H6 O3
C4 H8 O4
C5 H10 O5

20. Two monosaccharides
linked by dehydration synthesis
= disaccharide

21. 2 monosaccharides = disaccharide
3 monosaccharides = trisaccharide
Many monosaccharides = polysaccharide
(too many to count)
Monosaccharides
Disaccharides
= sugars
Fuzzy terminology:
Sometimes: All monosaccharides
disaccharides called "carbohydrates"
polysaccharides

22. Two Important Functions of Carbohydrates:
1) Storage of fuel for energy:
Amylose (starch) in plants; Glycogen in animals
Human cells can digest starch but not synthesize it.
They can both synthesize & digest glycogen

23. Two Important Functions of Carbohydrates:
Digestion of starch or glycogen in
the digestive system produces Glucose
(Scientists are lazy: Glucose & other
monosaccharides are often shown as
hexagons instead of drawing out all
the atoms)
which is further broken down within cells to release lots of energy.
Waste products: Carbon dioxide
Water

24. Two Important Functions of Carbohydrates:
(1. Storage of fuel for energy)
2) Structural carbohydrates
Many in extracellular matrix of all tissues
Receptors on cell surfaces
(usually bound to proteins or lipids)
(Cell walls in plants / bacteria = cellulose & others)
(Exoskeletons of invertebrates = chiton)
We will discuss the use of carbohydrates for producing energy and for use as structural molecules at various times throughout this course and BIOL 212

25. Lipid Fatty acids & Glycerol
Polymer: Monomers:
Protein Amino acids
Carbohydrate Monosaccharides
Lipid Fatty acids & Glycerol

26. Lipids: Molecules which are hydrophobic and do not mix
with water
Two major types: Fats (& Oils)
Steroids

27. If it’s solid at room temperature it’s a fat
Fats & Oils:
Monomer (basic repeating units) are fatty acids bound to a 3-carbon molecule called glycerol
If it’s solid at room temperature it’s a fat
If it’s liquid at room temperature it’s an oil
Fatty acids
Glycerol
(Scientists are lazy: Fatty acids are often shown as wavy lines
instead of drawing out all the atoms)

28. Fatty acids are long carbon chains (up to 20 or more carbons) with a carboxyl group at one end.
If they have no double
Bonds between carbons,
they are called
saturated fatty acids
If they have one or more
double bonds between
carbons, they are called
unsaturated fatty acids
Always an even number of carbons

29. Glycerol is a 3-carbon molecule to which fatty acids
bond by dehydration synthesis

30. Most common:
Diglycerides
(2 fatty acids
bound to
glycerol)
Triglycerides
(3 fatty acids

31. Diglycerides and triglycerides are energy-storage molecules.
They can be found in most type of cells, but are primarily found in adipocytes, in which they form large fat droplets in the center.
When needed for energy, fatty acids can be released from triglycerides and diglycerides and broken down to release energy. (we’ll discuss the details in BIOL 212)

32. Related to triglycerides are phospholipids, in which one fatty acid is replaced by a phosphate-containing group.

33. Phospholipids are major components of cellular membranes because the phosphate-containing group is highly hydrophilic while the fatty acids are highly hydrophobic
(Scientists are lazy:
Instead of drawing out all
the atoms, phospholipids
are often shown as a
circle for the phosphate
group with wavy lines for
the two fatty acids)
Phospholipids are also the surfactant molecules which allow the small air sacs (alveoli) of the lungs to stay open

34. Fats and oils are one type of “lipid” Another type of lipid: Steroids
Do not contain glycerol or fatty acids
Hormones from adrenal gland
testes
ovaries
Cholesterol
Vitamin D
Bile Salts (help absorb fat)
(other places)

35. Polymer: Monomers:
Protein Amino acids
Carbohydrate Monosaccharides
Lipid Fatty acids & Glycerol
Nucleic Acid Nucleotides

36. Each nucleotide has three parts:

37. There are five different base groups in nucleic acids
Both DNA & RNA
Adenine
Cytosine
Guanine
DNA
RNA
Uracil
Thymine

38. Ribonucleic acid
(single chain of nucleotides)

39. Deoxyribonucleic acid
(double chain of nucleotides)