Organic molecules in living systems include macromolecules made of polymers of smaller subunits. The four main types of macromolecules are lipids, proteins, carbohydrates, and nucleic acids. Lipids are made of fatty acids and glycerol and function in energy storage and cell membranes. Proteins consist of amino acid monomers and have roles as enzymes, membrane components, and tissues. Carbohydrates polymerize into sugars like starch from monosaccharides and serve as energy sources. Nucleic acids like DNA and RNA store genetic information as polymers of nucleotides. These macromolecules are broken down into their subunits during digestion and rebuilt in cells.

1. The Chemistry of the Cell
(Macromolecules)

2. Organic Molecules
• Organic molecules are those that have carbon atoms.
• In living systems, large organic molecules, called
macromolecules, may consist of hundreds or
thousands of atoms.
• Most macromolecules are polymers, molecules that
consist of a single unit (monomer) repeated many
times.

4. Carbon compound formation
Complex molecules can be formed by connecting carbon atoms
together in a straight line or by connecting carbons together to form
rings.
• The presence of nitrogen, oxygen, and other atoms adds additional
variety to these carbon molecules.

5. Functional groups
*Many organic
molecules share similar
properties because
they have similar
clusters of atoms,
called functional
groups.
• Each functional group
gives the molecule a
particular property,
such as acidity or
polarity.

6. Carbon based Molecules

7. What are Macromolecules?
 Cells and their organelles are made up of smaller
building blocks called macromolecules.
 There are 4 basic types of macromolecules.
They are:
 Lipids
 Proteins
 Carbohydrates
 Nucleic Acids

8. Monomers & Polymers
 Macromolecules are actually made up of even smaller
subunits. Each subunit of a macromolecule is called a
monomer.
 The macromolecules themselves are called polymers,
because they are made up of many of these subunits.
Monomer: one basic unit or subunit
Polymer: a chain of many basic units

9. What you need to know:
 Names of the 4 macromolecules
 Structure- monomers and polymers of each
 Function- what are they used for?

10. Lipids

11. Lipids
• Lipids are organic molecules essential
for life that are composed mostly of C,
H, O
• 4 types of lipids
– fats (triglycerides)
– phospholipids
– steroids
– waxes

12. Structure of Lipids
 Lipids are made up of monomers called fatty acids
 fatty acids have two essential features:
1. A long hydrocarbon chain
• The chain length ranges from 4 to 30 carbons
2. A carboxylic acid group

13. Properties of Lipids
resulted from:
1. Saturation of fatty
acids with Hydrogen:
Saturated f.a’s VS. Unsaturated f.a’s
2. Polarity:
 Some lipids consists of Polar head
(Hydrophilic) and nonpolar tail
regions (hydrophobic)

14. Triglycerides
– Fat molecules
• Structure = 3 fatty acids chains linked to
glycerol
• Functions = long term energy storage
• Can be saturated or unsaturated
Glycerol
3 fatty
acids
ester bond

15. Saturated fats
• All C bonded to H
• No C=C double bonds
– long, straight chain
– most animal fats and butter
– solid at room temperature

16. Unsaturated fats
• At least one C=C double
bond in the fatty acids
– plant & fish fats
– vegetable oils
– liquid at room temperature

17. • Structure: 2 fatty acids (tails) + phosphate
group (head)
• Fatty acid chains = non-polar = hydrophobic “water
fearing”
• Phosphate head = polar = hydrophillic “water loving”
•Function: make up cell
membranes (phospholipid bilayer)
Phospholipids

18. Steroids
• Structure: 4 fused Carbon rings
• examples:
– cholesterol – Function =control the fluidity of the cell
membrane
– hormones – Function = regulate many processes in the
body
– vitamins (A, B, D) – Function = supports metabolism and
cell processes

19. AP Biology
• Solid at room temp
• Insoluble in water
• Function:
– Protective
covering for
animals and plants
• Examples:
– Beeswax
– Cuticle of leaf (keeps
water in)
Wax

20. Functions of Lipids
 Make up the cell membrane, providing cell structure
 Provide insulation (fat keeps body warm)
 Long-term energy storage

21. Proteins

22. Structure of Proteins
 Proteins are made up of monomers
(basic unit) called amino acids
 There are 20 different a.a’s
 Proteins are also called
polypeptides
dipeptide
Amino acids
linked by
peptide
bonds

23. 20 Amino Acids:
Some of these are polar & hydrophilic, others are non-polar and
hydrophobic. Proteins can contain both kinds.

24.  Proteins have complex
structures. The shape of a
protein determines its function!
 The levels of protein structure
are:
 Primary structure: polypeptide
chain
 Secondary structure:
polypeptides in coils or sheets
 Tertiary structure: coils or
sheets form a tangle
 Quaternary structure: more
than one tangle combine to
make a very complex protein

25. Functions of Proteins
 Enzymes- proteins that speed up chemical reactions
 Component of Cell membrane
 Build and repair of muscles and
tissues
Ex. Actin, Myosin, Collagen….

26. Food Sources of Proteins
 Proteins are found in meat, fish, legumes, nuts, milk,
eggs, grains and soy products.
 There are 6 amino acids that our bodies cannot make-
we can only get these from food.
What are they called???

27. Research Question
 Which elements are found in protein????

28. Proteins: Indicator Test
 Biuret’s Test:
 Turns from blue to purple if protein is present

29. Carbohydrates

30. Structure of Carbohydrates
 Carbohydrates are made up of monomers called
monosaccharides.
 Ex.: Glucose, Fructose, ….
 When 2 Monosaccharides are linked
to each other they form a Disaccharide
galactose + glucose = ???
glucose + glucose = ???
glucose + fructose = ???
 Polymer (chain of units): polysaccharides
 Ex.: starch, cellulose, chitin, glycogen
Disaccharide:
2 simple
sugars bonded
together
Glucose

31. Functions of Carbohydrates
 Provide body with energy.
 What should you eat before
playing the big game?
Candy bar or pasta?
 Candy bar: contains simple
sugars, provides a short
burst of energy
 Pasta: contains starch
which takes longer to break
down, provides longer-
lasting energy
 Some carbohydrates are
indigestible by humans
such as cellulose, however,
it serves as fibers in the
digestive system.
Complex carb (ex. Starch)
Simple sugars (ex. Glucose)
Broken down to
disaccharides
Broken down further

32. Food Sources of
Carbohydrates
 Simple sugars are found in
most candy and sweet drinks,
fruit, vegetables, and milk.
They are quickly digested and
give a short burst of energy.
 Complex sugars (like starches)
are found in pasta, bread,
potatoes, legumes & corn. They
take longer to digest, and provide
energy longer.

33. Research Question
 Which elements are found in carbohydrates????

34. Carbohydrates: Indicator Tests
 Simple Sugars:
 Benedict’s solution
 Blue solution turns
orange/green/brown
 Complex sugars:
 Lugol’s
solution/Iodine
 Turns from orange-red-
brown to black-purple
starch
No starch

35. Nucleic Acids

36. Nucleic Acids: Structure
 Nucleic Acids are made up of monomers called
nucleotides
 Polymers (chain of units): DNA or RNA

37. Function of Nucleic Acids
 Stores and carries genetic information

38. Food Sources of Nucleic Acids
 We get nucleic acid components from vitamins and
minerals in our diet. These in turn, come from fruits,
vegetables, grains, meats, & almost anything else
you can think of with some nutritional value (no junk
food!).

39. Research Question
 Which elements are found in nucleic acids????

40. Nucleic Acids: Indicator Test
 You will not be using an indicator test for
these but in case you’re wondering…
 Dische diphenylamine test
 Turns from clear-light blue
to dark blue if nucleic acids
are present

41. Digestion & Reconstruction
 When macromolecules are eaten, they are digested and
broken down into their subunits (monomers).
 Inside the cells, these subunits are reconstructed into the
macromolecules we need.

42. Digestion Products
Macromolecule
eaten:
Broken down in stomach
to:
Carbohydrates Simple sugars (i.e. glucose)
Lipids Fatty acids & glycerol
(glycerol further broken
down to glucose)
Proteins Amino acids
Nucleic Acids Nucleotides