10/3/2014 1 Introduction to Biochemistry What is the chemical makeup of living things? Life is Organized in Increasing Levels of Complexity atom organelle tissue cell organ organ system organism simple molecule macromolecule Inorganic Molecules A. Water (H 2 0) 65-95% of the weight of an organism. Very good solvent (polar). Source of hydrogen and oxygen. Do NOT contain hydrocarbons(H connected to C). B. Carbon Dioxide (CO 2 ) Used by plants for photosynthesis. Source of carbon for organic molecules. C. Oxygen (O 2 ) 21% of air Needed for respiration (breakdown of food to release energy). Life is Organized in Increasing Levels of Complexity atom organelle tissue cell organ organ system organism simple molecule macromolecule Organic Molecules Carbon is very unique! It has up to 4 bonding sites. Able to form single, double, or triple bonds. Lots of possibilities! Composed of hydrocarbons.
Transcript
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Introduction to Biochemistry
What is the chemical makeup of living things?
Life is Organized in Increasing Levels of Complexity
atom
organelle
tissue
cell
organ
organ system
organism
simple molecule
macromolecule
Inorganic Molecules
A. Water (H20)
65-95% of the weight of an organism.
Very good solvent (polar).
Source of hydrogen and oxygen.
Do NOT contain hydrocarbons(H connected to C).
B. Carbon Dioxide (CO2) Used by plants for photosynthesis.
Source of carbon for organic molecules.
C. Oxygen (O2) 21% of air
Needed for respiration (breakdown of food to release energy).
Life is Organized in Increasing Levels of Complexity
atom
organelle
tissue
cell
organ
organ system
organism
simple molecule
macromolecule
Organic Molecules
Carbon is very unique! It has up to 4 bonding sites.
Able to form single, double, or triple bonds.
Lots of possibilities!
Composed of hydrocarbons.
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Why Carbon?
C C C
Major Classes of Organic Molecules
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
Important Terms
Polymer: large molecules made up of a repeating subunits
Train made of many cars (subunits)
Strand of pearls
Monomer: a single subunit used to build a polymer
Individual train car
Single pearl
Life builds itself up, then breaks itself down, in
never ending cycles of chemical reactions.
Life builds itself up and breaks itself down in never ending cycles of chemical reactions.
Learning Target:
Describe how polymers are built and broken down.
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How monomers join to form polymers?
Dehydration Synthesis: Process of removing water (“dehydrate”) to make a large molecule (“synthesize”).
OH H Monomer Monomer Monomer
1.
2.
3.
H Monomer OH Monomer Monomer OH H
H2O removed
H Monomer OH H Monomer OH H Monomer OH
H2O removed
How monomers join to form polymers?
Dehydration Synthesis: Process of removing water (“dehydrate”) to make a large molecule (“synthesize”).
OH H Monomer Monomer Monomer
1.
2.
3.
H Monomer OH Monomer Monomer OH H
H Monomer OH H Monomer OH H Monomer OH
How are polymers broken down into
monomers?
Hydrolysis: Addition of water (“hydro”) to split apart a
polymer (“lysis”).
OH H Monomer Monomer Monomer
H2O
1.
2.
3.
H Monomer OH Monomer Monomer OH H
H2O
H Monomer OH H Monomer OH H Monomer OH
Let’s Review!
What is the difference between organic and inorganic molecules?
What is a monomer?
What is an isomer?
What is a polymer?
What is dehydration synthesis?
What is hydrolysis?
Carbohydrates
Carbohydrates
What elements make up carbs?
C, H, and O.
Examples: sugar, starch, cellulose, etc.
What is the main function of carbs?
Primary energy source for organisms (food,
fuel, etc.).
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Monosaccharides
1. Monosaccharides: simple sugars.
All are C6H12O6.
“Quick” energy.
Examples…
“Mono” = One
“Saccharide” = Sugar
HO
Disaccharide
2. Disaccharide: double sugars.
2 monosaccharides
All are C12H22O11!
“Di” = Two
“Saccharide” = Sugar
C6H12O6
C6H12O6 +
C12H24O12
Making a disaccharide involves joining
two monosaccharides in a process
called
Dehydration Synthesis
Dehydration Synthesis of a Disaccharide
H20 Removed
REACTANTS PRODUCTS
Mono + Mono + E Disaccharide + water
+ E
Breaking apart a disaccharide involves
separating two monosaccharides in a
process called
Hydrolysis
Hydrolysis of a Disaccharide
+ E
Disaccharide + water Mono + Mono + E
REACTANTS PRODUCTS
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Polysaccharide
Complex carbohydrates
a) 3 or more sugars
b) Usually thousands of simple sugars c) Used for stored energy
“Poly” = Many
“Saccharide” = Sugar Examples of Polysaccharides
Starch: carb storage in plants
(usually in the roots).
Glycogen:
• Animal starch
• Storage of excess carbohydrates
• Found in muscle and liver
Cellulose:
• Structural material in
plant cell walls
• Major component of
wood
Review… What are the three types of carbohydrates?
More Review…
Which chemical process is illustrated below? How do you know?
Hydrolysis, water is being added to break down a molecule
Lipids
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Lipids
A) What elements compose Lipids?
C, H, and O…but greater proportion of H
atoms than in carbohydrates
What are some example?
Fats, Waxes, Oils
What two monomers make up Lipids?
1 Glycerol + 3 Fatty Acids
Dehydration
synthesis
Hydrolysis
Two Types of Fatty Acids
Saturated Fatty Acids
No double bonds between carbon atoms.
Very stable; hard to digest.
Animal fats (i.e. butter, bacon grease).
Solids at room temp
Cause of heart disease.
Carboxyl group
Two Types of Fatty Acids
Unsaturated Fatty Acids
Has double bonds between carbon atoms.
Less stable; easier to digest.
Liquids at room temp
Plant fats (peanut oil, corn oil, olive oil).
Do lipids like water?
No way!
Lipids DO NOT dissolve in water:
insoluble.
This is called hydrophobic:
water - fearing.
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Not all lipids are “bad” !!!
Fat is needed to allow vitamin
D to assist in calcium
absorption.
Steroids are lipds.
Ex. Hormones are steroids
that serves as chemical
messengers
Importance of Lipids
Long term storage of energy.
Major component of cell membranes.
Protective coat for animals.
Insulation
Cushions internal organs.
phospholipids
Let’s Review…
What two monomers make up a lipid?
How many fatty acids are found in a lipid?
What is the difference between a saturated and unsaturated
lipid?
Name at least two reasons why lipids are important.
Proteins
Protein Function
1. Form body/cell structures
for example:
Protein Function
Keratin Hair, nails, horns, claws.
Collagen Ligaments, cartilage, bone, tendons.
Hemoglobin Transports oxygen in red blood cells.
Muscle Movement and heart function.
Antibodies Fight off viruses and bacteria.
Membrane Channels Allow substances into and out of cells
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Protein Function cont’d
2. Control chemical reactions in cells as ENZYMES
Enzymes are very efficient catalysts for biochemical
reactions
CATALYSTS: molecules that speed up reaction rates
(SEE MORE DETAILS ON ENZYMES ON PAGE 9)
Protein Structure
Proteins(large polymers) are composed of
monomers called AMINO ACIDS.
They contain elements C, H, O, and N.
Most abundant organic compound
There are 20 different kinds of amino acids, all
with the same basic structure!
What is the basic structure of an amino acid?
Amino group Carboxyl
group
R group
(side chain)
Hydrogen
atom
Amino acids are named for their different “R”
groups (3 out of 20 shown below).
R-Group: side chain that
makes each amino acid
(monomer) unique.
How are proteins made?
Dehydration synthesis -the amino group (-NH2) reacts
with the carboxyl group (-COOH).
Peptide Bond: a bond formed between amino acids.
Dipeptide: TWO amino acids bonded together.
Polypeptide: more than two amino acids bonded
together..
+ +
+ 2 H20
Peptide Bonds
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How is protein structure determined?
Sequence of the amino acids determines the
protein’s folding pattern and therefore its
unique 3-D structure.
The unique 3-D structure determines its
FUNCTION.
***Proteins contain 1000s of amino acids***
Two sample polypeptide chains: Polypeptide A
Ala- Ser-Tyr- Ala-Glu- Ser- Glu– Glu –Phe –Try- Ser
Polypeptide B
Ala- Ser-Tyr- Ala- Glu- Ser- Glu- Phe- Try- Ser- Ala
Fibrous Proteins
Usually structural proteins.
Globular Proteins
Usually enzymes.
Structural
Proteins
Enzymes
Remember!!!
Sequence of AA determines how it folds
determines its shape determines proteins
function
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ENZYMES are globular proteins that control
chemical reactions in living things.
In any living thing, the chance that two molecules
(A and B) will meet and react at the right place, the right time, and in the right positions is completely RANDOM.
