CHAPTER 6.4 The Structure and Function of Macromolecules

1
CHAPTER 6.4The Structure and Function of
Macromolecules

• You are what you eat!

2
6.4 The Building Blocks of Life

• The elements of life
• Organisms are made up of cells. Cells contain
  molecules made up of the following elements
• CHNOPS
• Carbon (C)
• Hydrogen (H)
• Nitrogen (N)
• Oxygen (O)
• Phosphorus (P)
• Sulfur (S)
• These elements come from the foods we eat.

3
Matter Cannot be Created nor Destroyed!

• It gets recycled!!!!

4
How does CHONPS get into our cells?

5
Carbon

• All life on Earth is made of carbon-containing
  molecules.
• Carbon can form 4 covalent bonds with other
  atoms.
• Examples
• Glucose (C6H1206)
• Carbon Dioxide (CO2)
• The chemistry of all living things is based on
  the key element CARBON

6
Organic Chemistry

• Because of the many important and unique
  properties of carbon-based molecules, there is a
  special branch of chemistry devoted just to the
  study of these molecules.
• Organic chemistry is the study of compounds
  containing carbon.
• The carbon compounds we are studying are called
  Macromolecules.

7
There are 4 major categories of macromolecules
http//www.brainpop.com/health/bodysystems/bodyche
mistry/

• Carbohydrates
• CHO
• Lipids
• CHO
• Proteins
• CHONPS
• Nucleic Acids
• CHNOP

8
What does it mean to be a MACROmolecule?

• You must be a Large molecule
• You have a complex structure

Macromolecule
little molecule
9
I. Most macromolecules are polymers, built from
monomers

• What is a polymer?
• Poly many mer part.
• A long molecule made of monomers bonded together
• What is a monomer?
• A monomer is a sub-unit of a polymer.

10

• Three of the classes of lifes organic molecules
  are polymers (made up of monomers)
• Carbohydrates, Proteins, Nucleic acids

11
A. Making and Breaking Polymers

• How do monomers bind to form polymers?
• condensation reactions called dehydration
  synthesis (removal of water)

12
How can polymers break down when monomers are
needed?

• Hydrolysis reaction
• Hydro water lysis break
• Water is added and the lysis of the polymer
  occurs.

13
Hydrolysis
14
II. Classes of Organic Molecules

• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

15
1. CARBOHYDRATES
16

• What are Carbohydrates?
• Sugars and their polymers
• Carbo carbon, hydrate water carbohydrates
  have the molecular formula (CH2O)n
• Functions of Carbohydrates in living things
• Major fuel/energy source
• Can be used as raw materials for other
  Macromolecules
• Complex sugars building material in plants
• What is the Carbohydrate Monomer?
• Monosaccharide (mono one saccharide
  sugar)

17
1. Structure of Monosaccharides

• Contain only C, H, O
• Hydroxyl group is attached to each carbon
• One carbon contains a carbonyl group

18

• Classified according to the size of their carbon
  chains and location of Carbonyl group

19

• In aqueous solutions many monosaccharides form
  rings

20
2. Structure of Disaccharides

• Consist of two monosaccharides
• Are joined by a glycosidic linkage
• What reaction forms the glycosidic linkage?
• Dehydration synthesis

21
(No Transcript)
22
3. Polysaccharides

• Structure Polymers of a few hundred or a few
  thousand monosaccharides.
• Functions energy storage molecules or for
  structural support

23
(No Transcript)
24

• Starch is a plant storage form of energy, easily
  hydrolyzed to glucose units

25

• Cellulose is a fiber-like structural material
  made of glucose monomers used in plant cell walls

26
Why is Cellulose so strong?

• Glucose monomers are flipped to expose equal
  Hydroxyl groups on either side of the chain
• When Cellulose chains are lined up next to each
  other, they Hydrogen Bond making a strong
  material thats difficult to break!

27
(No Transcript)
28

• Glycogen is the animal short-term storage form of
  energy
• Glucose monomers

29

• Chitin is a polysaccharide used as a structural
  material in arthropod exoskeleton and fungal cell
  walls.

30
2. LIPIDS

• What are Lipids?
• Fats, phospholipids, steroids, waxes, pigments
• Hydrophobic (hydrowater phobic fearing)
• Consist mostly of hydrocarbons
• Do NOT consist of monomers and polymers

31

• Functions of Lipids in living things
• Energy storage
• membrane structure
• Protects against desiccation (drying out)
• Insulates against cold.
• Absorbing shock

32
1. Structure of Lipids

• Consist of a single glycerol and usually 1-3
  fatty acid hydrocarbon chains
• Glycerol an alcohol with three carbons
• Fatty Acid - Long Hydrocarbon chains with a
  Carboxyl group at one end.

33
Saturated and Unsaturated Fats

• Unsaturated fats
• one or more double bonds between carbons in the
  fatty acids allows for kinks in the tails
• liquid at room temp
• most plant fats
• Saturated fats
• No double bonds in fatty acid tails
• solid at room temp
• most animal fats

34
(No Transcript)
35
Saturated fatty acid
36
A. Phospholipids

• Structure Glycerol 2 fatty acids phosphate
  group.
• Function Main structural component of
  membranes, where they arrange in bilayers.

37
Phospholipids in Water
38
B. Triglycerides

• Structure - Have one glycerol and three fatty
  acid chains
• Function - necessary for certain bodily functions
  (fat stores), but high levels of them can lead to
  heart disease.

39
This is a triglyceride
40
C. Waxes

• Function
• Lipids that serve as coatings for plant parts and
  as animal coverings.

41
D. Steroids

• Structure Four carbon rings with no fatty acid
  tails
• Functions
• Component of animal cell membranes (Ex
  Cholesterol)
• Modified to form sex hormones

42
PROTEINS
43
3. Proteins

• What are Proteins?
• Chains of amino acid monomers connected by
  peptide bonds
• Have a 3 dimensional globular shape

44
Examples of Protein Functions

• Enzymes (see next slide for a visual)
• Act as catalysts to speed up the rate of
  reactions
• Immune System
• Binding of antibodies (proteins) to foreign
  substances in the body
• Transport
• Transport proteins move substances across cell
  membranes
• Hemoglobin carries oxygen, iron, and other
  substances through the body
• Muscle Contraction
• actin and myosin protein fibers interact in
  muscle tissue
• Cell Signaling
• Hormones such as insulin regulate sugar levels in
  blood

45
Enzymes

• Are a type of protein that acts as a catalyst,
  speeding up chemical reactions up to 10 billion
  times faster than they would spontaneously occur.

46
(No Transcript)
47
Amino Acids

• Are the monomers of polypeptides
• Structure amino groups, carboxyl groups, and
• Differing side chains, called R groups, effects
  the properties of amino acids.

48
20 different amino acids
The sequence of amino acids and the interactions
of the different amino acids determine a proteins
shape
49

• Peptide bonds connect amino acids to form
  polypeptide chains
• One or more polypeptide chains make up a protein

50
Proteins are very complex! Their specific
structure determines their function.
HEMOGLOBIN Transport of gases and iron in blood
ACTIN Filament involved in muscle contraction
51
Four Levels of Protein Structure

• Primary structure
• Is the unique sequence of amino acids in a
  polypeptide

52

• Secondary structure
• Is the folding or coiling of the polypeptide into
  a repeating configuration resulting from hydrogen
  bonding of amino with carboxyl groups
• Includes the a helix and the ß pleated sheet

53

• Tertiary structure
• Is the overall three-dimensional shape of a
  polypeptide
• Results from interactions between amino acids and
  R groups

54

• Quaternary structure
• Is the overall protein structure that results
  from the aggregation of two or more polypeptide
  subunits

55

• Chaperonins
• Are protein molecules that assist in the proper
  folding of other proteins

56
Sickle Cell Disease A simple change in Primary
Structure
57
Factors That Affect Protein Shape

• Proteins can denature (fall apart) if
• pH is too high or too low
• Temperature is too high
• Salinity is too high
• Denatured proteins are biologically inactive

58
NUCLEIC ACIDS
59
4. Nucleic Acids The stuff of Genes

• Nucleic acids store and transmit hereditary
  information
• Genes
• Are the units of inheritance
• Program the amino acid sequence of polypeptides
• Are made of nucleic acids

60
Two Kinds of Nucleic Acids

• DNA (Deoxyribonucleic acid)
• double stranded
• can self replicate
• makes up genes which code for proteins
• is passed from one generation to another
• RNA (Ribonucleic acid)
• single stranded
• functions in actual synthesis of proteins coded
  for by DNA
• is made from DNA

61
(No Transcript)
62
1. Monomers of Nucleic Acids

• Both DNA and RNA are composed of nucleotide
  monomers.
• Nucleotides are composed of a 5 carbon sugar, a
  phosphate group, and a nitrogenous base

Nitrogenous Base
Phosphate
5 Carbon Sugar
63
(No Transcript)
64
2. Building the Polymer

• On your paper, label the phosphate groups and 5
  carbon sugars. List the 4 different kinds of
  nitrogenous bases, too.

65

• DNA
• Double helix
• 2 polynucleotide chains wound into the double
  helix
• Base pairing between chains with H bonds
• A - T
• C - G

66
Summary of the Organic Molecules
67
Saturated fatty acid
Unsaturated fatty acid
Why are Unsaturated Fats better for you than
Saturated Fats?