THE MOLECULES OF LIFE

1
In the beginning God created the heavens and
earth... -Gen 11
Welcome to Biology!
Block 3
Nielsen, Caleb Chaverri, Patrick Merritt, Emily Lee, Sung Jin "Felix Roccuzzo, John Loria, Charles Gulick, Emma Wolf, Elijah

Meyer, Nicolas Georgina Santhosh Smith, Bethany Obrecht, Nathaniel Michaela Korman D'Haiti, David Schneider Christian Jiao, Peng "Anna"

 


Front of the room
2
In the beginning God created the heavens and
earth... -Gen 11
Welcome to Biology!
Front of the room
Block 3
Nielsen, Caleb Chaverri, Patrick Merritt, Emily Lee, Sung Jin "Felix Roccuzzo, John Loria, Charles

Meyer, Nicolas Georgina Santhosh Smith, Bethany Obrecht, Nathaniel Michaela Korman D'Haiti, David

Gulick, Emma Wolf, Elijah Schneider Christian Jiao, Peng "Anna"


3
Carbon is the main ingredient of organic
macromolecules. (Concept 5.1 ) page 92
4
Carbon Skeletons and Functional Groups

• organic molecule carbon-based molecule
• inorganic molecule non-carbon-based molecule
• hydrocarbon organic molecule composed of only
  carbon and hydrogen atoms
• E.g Methane CH4 most abundant hydrocarbons in
  natural gas.

5
Carbon Skeletons and Functional Groups

• functional group group of atoms within a
  molecule that interacts in predictable ways with
  other molecules
• E.g. hydroxyl groups are hydrophilic.
• hydrophilic attracts water molecules.

6
Monomers and Polymers

• Some biomolecules may be composed of hundreds or
  even millions of atoms.
• monomer small molecular unit that is the
  building block of a larger molecule
• polymer long chain of small molecular units
  (monomers)
• Life's large molecules are classified into four
  main categories carbohydrates,
• lipids,
• proteins,
• and nucleic acids.

7
Building and Breaking Polymers

• Each time a monomer is added to a chain, a water
  molecule is released, This is called a
  dehydration reaction because it involves removing
  (de-) water (hydro-).
• Cells break bonds between monomers by adding
  water to them, the reverse of dehydration, This
  process is called a hydrolysis reaction because
  water (hydro-) is used to break down (-lysis) the
  polymer.
• Activity 5.1

8
Concept Check 5.11. Draw a molecule that has
a three-carbon skeleton and a hydroxyl group on
the middle carbon. (Hint The molecule's formula
is C3H8O.) 2. Explain the connection between
monomers and polymers.3. What molecule is
released during construction of a polymer? What
is this reaction called?4. Draw at least three
ways in which five carbon atoms could be joined
to make different carbon skeletons.
9
Carbohydrates provide fuel and building
material. (Concept 5.2 ) page 95
10
Sugars

• carbohydrate organic compound made of sugar
  molecules (Carbo hydrate)
• Contains carbon, hydrogen, and oxygen in the
  ratio of
• 1 2 1. 1carbon 1hydrogen 1oxygen
• Basic formula of CH2O. Most found in nature have
  a ring shape.

11
Sugars
Monosaccharide

• monosaccharide sugar containing one sugar unit
• Glucose, fructose, and galactose are examples of
  monosaccharides. (suffix -ose.)
• E.g. Honey contains both glucose and fructose.
• Glucose exists in both straight-chain and
  ring-shaped forms.
• Used for energy, or stored as
• large carbohydrate, or used to
• make fat molecules.

12
Sugars
Disaccharides

• disaccharide sugar containing two
  monosaccharides.
• Using the dehydration reaction, cells construct
  from two monosaccharides.
• The most common disaccharide is sucrose glucose
  fructose.
• E.g. Plant sap (maple syrup) contains sucrose.
• E.g. Table sugar is sucrose.

13
Polysaccharides

• polysaccharide long polymer chain made up of
  simple sugar monomers
• E.g starch polysaccharide in plant cells that
  consists entirely of glucose monomers .
• Humans and most other animals are also able to
  use plant starch as food by breaking it down
  within their digestive systems.
• Potatoes, rice, and corn
• are examples of foods rich in starch.

14
Polysaccharides

• glycogen polysaccharide in animal cells that
  consists of many glucose monomers.
• In humans, most glycogen is stored as granules in
  liver and muscle cells. When the body needs
  energy, it breaks down these glycogen granules,
  releasing glucose.
• cellulose polysaccharide consisting of glucose
  monomers that reinforces plant-cell walls
• Read last two paragraphs in 5.2

15
Figure 5-8Glycogen, cellulose, and starch are
three types of polysaccharides found in food.
Though all three polymers are composed of the
same monomer, glucose, the way the glucose
monomers link together is different for each.
Activity 5.2
16
Concept Check 5.21. Explain the difference
between a monosaccharide and a disaccharide. Give
an example of each.2. Compare and contrast
starch, glycogen, and cellulose.3. How do
animals store excess glucose molecules?
Meet two Biochemists
17
Lipids include fats and steroids. (Concept
5.3 ) page 98-list-Demo
18
Characteristics of Lipids

• lipid one of a class of water-avoiding compounds
• hydrophobic avoids water molecules
• lipids act as a boundary that surrounds and
  contains the aqueous (watery) contents of your
  cells.
• lipids circulate in your body as chemical signals
  to cells.
• lipids known as fats store
• energy in your body.

19
Fats

• fat organic compound consisting of a
  three-carbon backbone (glycerol) attached to
  three fatty acids
• Some fats are solid at room temperature. Other
  fats called oils are liquids at room temperature.
  
• In addition to storing energy for later use,
  fatty tissues cushion your organs and provide
  your body with insulation.

20
Fats

• saturated fat fat in which all three fatty acid
  chains contain the maximum possible number of
  hydrogen atoms .
• (Most animal fats, such as lard and butter, are
  saturated. They are solid at room temperature.)
• unsaturated fat fat with less than the maximum
  number of hydrogens in one or more of its fatty
  acid chains.
• (The fats in fruits, vegetables, and fish are
  generally unsaturated, as are corn oil, olive
  oil, and other vegetable oils.)

21
Figure 5-9Certain vegetable oils contain
unsaturated fat molecules, which have at least
one double bond in at least one of the fatty acid
chains. In this case, the double bond is located
about halfway along the bottom chain.
22
Steriods

• steroid lipid molecule with four fused carbon
  rings.
• Steroids are classified as lipids because they
  are hydrophobic, but they are very different from
  fats in structure and function.
• Some steroids circulate in your body as chemical
  signals. The steroids estrogen, a female sex
  hormone, and testosterone, a male sex hormone,
  function in this way.

23
Figure 5-10The only difference in these two
steroid hormones is the location of their
functional groups. Yet, these two molecules
contribute to major differences in the appearance
and behavior of male and female mammals.
24
Steriods

• cholesterol essential steroid molecule present
  in the plasma membranes of animal cells.

Activity 5.3
25
Concept Check 5.31. What property do
lipids share?2. What are the parts of a fat
molecule?3. Describe two ways that steroids
differ from fats.4. What does the term
unsaturated fat on a food label mean?
-Finish Macromolecule Lab concept check
5.3 -Online resources -Outline 5.4
26
Proteins perform most function in cells.
(Concept 5.4 ) page 100
27
The functions of proteins.

• protein a polymer constructed from a set of just
  20 kinds of monomers called amino acids.
• For example
• -hair, fur, muscles.
• -long-term nutrient storage.
• -circulate in the blood and defend the body from
  harmful microorganisms.
• -act as signals, conveying messages from one
  cell to another.
• -controls the chemical reactions in a cell.
• Structure of proteins is key to understanding its
  function.