Transcript THE MOLECULES OF LIFE - Christian Heritage School

“In the beginning God created the heavens and earth...” -Gen 1:1
Welcome to
Biology!
Block 3
Front of the room
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"
“In the beginning God created the heavens and earth...” -Gen 1:1
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"
Carbon is the main ingredient of
organic macromolecules.
(Concept 5.1 )
page 92
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.
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.
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.
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
Concept Check 5.1
1. 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.
Carbohydrates provide fuel
and building material.
(Concept 5.2 )
page 95
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.
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.
Disaccharides
Sugars
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.

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.
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
Figure 5-8
Glycogen, 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
Concept Check 5.2
1. 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
Lipids include fats and
steroids.
(Concept 5.3 )
page 98
-list
-Demo
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.
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.
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.)
Figure 5-9
Certain 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.
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.
Figure 5-10
The 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.
Steriods

cholesterol: essential steroid molecule present in the
plasma membranes of animal cells.
Activity 5.3
Concept Check 5.3
1. 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
Proteins perform most function
in cells.
(Concept 5.4 )
page 100
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.