The Chemical Level of Organization
AtomsMoleculesMacromolecules• Organic v. inorganic• 4 major macromolecules• Water• Acids/bases
Macromolecules
Large Molecules
There are 4 primary types of macromolecules• Carbohydrates• Lipids• Proteins• Nucleic Acids
Carbohydrates
Composition (elemental)C, H, O’s
Twice as many H’s as O’s
Simple sugars
Complex carbohydrate
Carbohydrates Cont.Made of Elements• C, H, O (twice as many H’s as O’s or C’s)
Structure: rings or chains of carbons• Monosaccharides: a single chain or ring
e.g., glucose, fructose, galactoseInteresting note; glucose and fructose are isomers
• Dissaccharides: two monosaccharides bonded togethere.g., sucrose, maltose, lactose
• Polysaccharides: many monosaccharides bonded togethere.g., glycogen, starch
Important Characteristic• Carbs are polar and mix/dissolve well in water
-Water soluble
What are carbohydrates used for?
Major Functions:• Structural: they are building materials for
cells and tissues.
• Energy Release: the covalent bonds in carbs are broken to release energy for cells to use
• Energy Storage: carbs can be added together to store chemical energy for future use
LIPIDS
Made of Elements:• C, H, O’s (relatively few O’s)
Unsaturated fat (triglyceride)
LIPIDS
Made of Elements:• C, H, O’s (relatively few O’s)
Important Characteristic• Non-polar
-not water soluble
Types of Lipids• Triglycerides• Phospholipids• Eicosanoids (inc. prostaglandins)
• Steroids (cholesterol & hormones)
• Fat Soluble Vitamins (vitamins A, K, D, & E)
LIPID FUNCTIONS:What lipids are used for
Depending on the type of lipid:Energy Storage and Release • (e.g. triglycerides)
Insulation • (e.g., triglicerides)
Building Material/Structural • (e.g., phospholipids help make the plasma membrane of cells)
Chemical Signalers/Hormones (regulate activity)• (e.g., steroid based hormones send signals to cells that regulate/alter activity of the
receiving cell)
Fat Substitutes
Olestra; can’t be broken down
Xenical (a.k.a. Alli); a drug that blocks pancreatic lipase/enzymes so lipids are not broken down and therefore not absorbed so no caloric intake occurs…..but wear dark pants…..
What are Proteins?Made of Elements• C, H, O, + N
Structure• made of amino acids linked together• 20 different types of amino acids
--different combinations of amino acids make different kinds of proteins--200,000+ different types in humans
• amino acids are covalently bonded-peptide bond
What are Proteins?Protiens are made of chains of amino acids that fold into a specific 3D shape.
Amino acids
Proteins
Protein shape is very important to its function
Simple chains of amino acids –> primary structure
Primary structures folds to creating twists and folds due to hydrogen (and other weak) bonds secondary structure
The protein then folds again to make into a distinct 3D shapetertiary structure
some conditions can cause the protein to lose its shape—denature—and stop functioning
Primary structure
Secondary structure
Tertiary structure 3D shape related to function of protein
folding
folding
Proteins are used for/to:Major Functions
Structural: they are building materials of cells and other body material
Hormones: regulate phys and dev
Enzymes: initiate and regulate chemical reactions (rxns)
Receptors: binding sites on cells for other molecules
transport: moves things across the plasma membrane, within cells, and through blood
Movement: produces contraction/movement
Antibodies: fight infections/immune response
To a lesser extent: an energy source
EnzymesProteins that promote chemical reactions• Almost all chemical reactions in the body
“need” an enzyme to occur• Specific enzymes promote specific reactions• Allows reactions to be regulated• No enzymes no reaction
What are Nucleic Acids?
Made of Elements:• C, H, O, N, + P
Three Types• DNA• RNA• ATP
DNAFunction:
Instructions/Information on how to build and operate cells, to repair cell damage, and to make anything the cell needs to produce• When and how to make protiens• Heritable genetic material: passed from one
cell to the next (and from one generation to the next via sperm and eggs….which are cells)
DNAStructure• Made of nucleotides
-- 4 different nucleotides each with a different base molecule
• A double strand of nucleotides that are twisted like a corkscrew
• Organized into chromosomes
B
RNAStructure• A single strand of nucleotides
Many different forms of RNA
Function of mRNA• It is a copy of DNA’s protein building
instructions that is used to directly make proteins
ATP
Structure:• A molecule of adenosine + 3 phosphates
Function:• Energy from broken down carbs, lipids, and
proteins are transferred to ATP.• ATP is the direct source of chemical energy for
cell activity
ATP-ADP Cycle
ATP
ADP
Phosphate
+
Energy from broken
covalent bond
(e.g., carbs)
Phosphate
+
Usable energy for cell
ACIDS AND BASES
Acidsproduce hydrogen ions H+
• Increased H+ in solution
• Lower the pH, the more acidic
Basesproduce hydroxide ions OH-
• Increased OH- (or decreased H+) in solution
• the higher the pH, the more basic
• Alkaline=basic
Acids and Bases / pH scale
The more acidic, the lower the pH value
Refer to your lecture notes for:
Organic v. inorganicThe Properties of Water
“COMPOSITE MOLECULES”
glycolipids• sugar/carb + lipid
Glycoprotein• sugar/carb + protein
Lipoprotein• Lipid + protein
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