macromolecules macromolecules (1000’s of atoms and weigh over 100,000 daltons) 4 kinds of...
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MACROMOLECULES
• Macromolecules (1000’s of atoms and weigh over 100,000 daltons)
• 4 Kinds of macromolecules: Carbohydrates, lipids, proteins, and nucleic acids (know this in your sleep!)
MACROMOLECULES ARE:
POLYMERS: chainlike molecules made up of -
MONOMERS: (the repeated units)
Diversity of Polymers – different sequences of the basic 40-50 monomers
How do monomers make polymers? Condensation /Dehydration
reaction: One monomer provides
an ‘–OH’ and the other provides a ‘-H’ and together these form H2O
H2O is REMOVED; Covalent bond is formed between MONOMERS = Polymers are made!
Needs ATP and Enzymes Anabolic/biosynthesis reactions use
this to make macromolecules for growth/replacement
How do polymers break up?
Hydrolysis Reaction: Covalent Bond is broken; H2O
is added across the broken bond
Polymers make Monomers Provides ATP and Uses
Enzymes Used for digestion, cell
respiration
I) Sugars are all - Carbohydrates
Monomer Unit of Carbohydrates called: Monosaccharides
Polymer called PolysaccharideGeneral formula: [CH2O]n
– For example, glucose has the formula C6H12O6.
– Most names for sugars end in -ose.
FRUCTOSE (from FRUIT!!)
LACTOSE (from MILK)
MALTOSE (from ‘Malt’ – a fermentation product)
SUCROSE (from cane sugar)
DEXTROSE (=glucose)
Monosaccharide Classification Overview:
1) Based on Aldehyde or Ketone Functional group (aldose/ketose)
2) Number of Carbon atoms (pentose, hexose…)3) Arrangement of Carbon Atoms - Isomers4) Straight chain or ring structure
- Know how to identify a simple sugar/monosachcharide by sight as a ring structure and a straight chain structure
- Know the glycosidic linkage is represented as an -O- when 2 monosachcharides are connected
Monosaccharide Classification
1) Based on Functional Group:
• KETOSE = Ketone function group (C=O)
• ALDOSE = Aldehyde functional group
(-CHO)
FRUCTOSE GLUCOSE
Monosaccharide Classification
2) Based on Number of Carbons:
HEXOSE = 6 C PENTOSE = 5 C TRIOSE = 3C
GLUCOSE (6)RIBOSE (5)
Monosaccharide Classification
3) Based on Arrangement of Carbon Atoms:
Enantiomers: Isomers (Glucose and Galactose)
No test ques. on this for your level!
Monosaccharide Classification4) Based on Ring Structure : Linear monomers form rings in solutions (Alpha and Beta Rings – based on plane of –OH -skip details)
Monosaccharide to Disaccharide(dehydration reaction)
Glucose Fructose+ = Sucrose
Glucose + Galactose = Lactose
Glucose + Glucose = Maltose
- Important Disaccharides (Sucrose – table sugar, Lactose – Milk, Maltose – Beer)
Monosaccharide to Disaccharide A Glucose monomer and a fructose monomer can be joined using a GLYCOSIDIC LINKAGE to form
SUCROSE (know to identify this link) SUCROSE is a DISACCHARIDE
Glucose
FructoseSUCROSE
Monosaccharide to Disaccharide A Glucose monomer and a fructose monomer can be joined using a GLYCOSIDIC LINKAGE to form
SUCROSE SUCROSE (table sugar) is a DISACCHARIDE
Glucose
FructoseSUCROSE
Monosaccharide to Polysaccharide
G G+
= Polysaccharide
G + G+
- 1000’s of monosaccharides join up to form POLYSACCHARIDES
+ ………………
Carbohydrate ReviewMonosacharrides Disacharrides
(glucose, fructose) (sucrose, lactose)
Condensation/dehydration reaction
Polysacharrides
Structural Storage
Cellulose Starch (Plant)
Chitin Glycogen (Animals)+ +
a) Storage Polysaccharides
1) STARCH (in potatoes – ‘stored NRG’ in plants)
MONOMER is Glucose
Links up to form starch many, many glucose molecs)
a) Storage Polysaccharides
1) STARCH has 2 polymers: (skip details)
1-4 linkage of Glucose Monomers (amylose -helical)
1-6 linkages causes branching (amylopectin)
a) Storage Polysaccharides
2) GLYCOGEN
(in animals – ‘stored ATP’ in muscle and liver)
MONOMERS – Glucose
b) Structural Polysaccharides
1) CELLULOSE
(in plant cell wall)
Monomers-Glucose
1-4 linkage
b) Structural Polysaccharides
2) CHITIN
(in exoskeleton of arthropods)
Monomers-Glucose
Glucose has a ‘-N group’ attached
Starch Test – Lugol’s Iodine
Benedict’s Test
• Will be positive for Reducing Sugars (monosaccharides, disaccharides except sucrose)
Benedict’s Test
• CuSO4 Cu++ + SO4
--
• 2 Cu++ + Reducing
Sugar Cu+ (electron donor)
• Cu+ Cu2O
II) Lipids
Lipids – are hydrophobic
(mostly hydrocarbons) They are NOT polymers Important classes: FATS,
PHOSPHOLIPIDS, and STEROIDS
FATS
Fats– are triglycerides - have glycerol and fattyacids linked up by an ‘ester’ bond
Glycerol is a 3C alcohol
Fatty acid is RCOOH and can have long hydrophobic C-H chains- these can have double bonds or single bonds or a mixture
Saturated fats - solids at room temp. - have all Carbons SATURATED - that means every carbon has max. number of hydrogen attached Ex. butterUnsaturated fats - liquid at room temp. - have some Carbons UNSATURATED - that means DOUBLE BONDS from some carbons having less than max. number of hydrogen attached Ex. Oil. DOUBLE BONDS = freedom of movement!
CARCINOGENIC
Percent Fatty Acid Present in Triglycerides
Fat or Oil Saturated Unsaturated
Palmitic Stearic Oleic Linoleic Other
Animal Origin
Butter 29 9 27 4 31
Lard 30 18 41 6 5
Beef 32 25 38 3 2
Vegetable Origin
Corn oil 10 4 34 48 4
Soybean 7 3 25 56 9
Peanut 7 5 60 21 7
Olive 6 4 83 7 -
Artherosclerosis-plaque in artery
Fat Substitutes
• Olestra - sucrose (sugar) with fatty acids (No digestion!!)
• Hydrogenated Vegetable Oils: Peanut Butter, Shortening, Margarine
Fat Functions
• Energy Storage (1 gm of fat = 2 gm starch; fat- 4 cal/gm)
• Plants use starch to store energy (bulky); seeds have oil
• Animals – store energy as fat• Insulation; Protect vital organs• Absorption of Vitamins K, E,
D, A
Phospholipids
• Two fatty acids attached to glycerol and a phosphate group at the third position
• Phosphate Group is –ve
• R – fatty acid hydrocarbon chain
• X – other groups
• Fatty acids (hydrophobic)+ glycerol+ phosphate group +polar group (hydrophilic)
• The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head
• -know to recognize it!
Steroids
• Consist of 4 fused rings
• Cholesterol, sex hormones
• Vary in functional groups
Lipid Test
• Brown paper turns translucent with lipid (grease test)
• Sudan IV Test:
Proteins
• Proteios – first place!!
• Polymers made up of Amino Acid Monomers
Amino Acids
• Have Carboxyl (COOH) and amino groups (NH2)
• Center – Alpha Carbon
• ‘R’ – 20 different possibilities = 20 amino acids
• Ionized at neutral pH inside the cell (COO- and NH3
+)
Amino Acids
• Hydrophobic ‘R’ groups
Amino Acids
• Hydrophilic Polar ‘R’ groups
Amino Acids
• Electrically charged ‘R’ groups (Acidic/ Basic; also hydrophilic)
Amino Acids
• Peptide Bond Formation: (O=C-NH) Dehydration reaction linking amino acid monomers into a polypeptide chain- know this bond!
Amino Acids
• Primary Structure: Sequence of amino acid chain - is it Val-His-Leu… or Val-Glu-Leu….
• Change in Primary Structure can cause protein to function abnormally (DUH!)
Amino Acids
• Secondary Structure: Result of H Bonding between O=C and N-H (atoms in this secondary structure are in the polypeptide backbone)
Helix (coils) – every 4th aa linked Pleated Sheets (folds)
Lysozyme
Helix
Pleated Sheets
Amino Acids
• Tertiary Structure: Result of H Bonding between side chain ‘R’ groups H bonds among polar and/or
charged groups; ionic bonds between charged
R groups, and hydrophobic interactions
and van der Waals interactions among hydrophobic Rgroups
Disulfide Bridges (know this is important in tertiary structure!)
Amino Acids
• Quarternary Structure: Result of noncovalent interactions between polypeptide chainsDimers, Trimers,
Tetramers – aggregations of many polypeptide subunits
Why is folding important?
“Diseased prions induce healthy prion proteins to change their shape, and clusters of disease build, leaving holes in the brain.” – SF Chronicle
Denaturation
• Protein Denaturation – Loss of biological activity• Loss of Native Confirmation/folding due to changes in pH, salt concentration, temperature • Protein can come back to original confirmation (Renatured)
Chaperonins
• The folding of many proteins is protected in cells by chaperonin proteins that shield out bad influences.
Biuret Test
• Biuret Reagent has CuSO4 and KOH
• Blue-violet = proteins• Purple/pink = peptides• Will not detect free amino
acids
• Amino Acid Sequence of a Polypeptide is coded by a GENE
• A gene is a specific sequence of DNA
• DNA is made of Nucleic Acids
Nucleic Acids
• GENE codes for a messenger RNA in the nucleus
• mRNA is translated in the cytoplasm
• Protein is synthesized using the mRNA
Nucleic Acids
Nucleic Acids
• DNA and RNA are Nucleic Acids
• Nucleic Acids are Polymers
• The monomers are called NUCLEOTIDES
Nucleotides
• NUCLEOTIDES are made of:
• Pentose Sugar• Nitrogen Base• Phosphate group
Nucleotides- Nitrogen Base
• Nitrogen Base can be of 2 types:
• Purine – 2 rings; Adenine and Guanine
• Pyrimidine – 1 ring; Cytosine, Uracil, and Thymine
Nucleotides- Nitrogen Base
• Purines and Pyrimidines bond with each other
• A can form a bond with T or U
• G can form a bond with C
Nucleotides-Sugar
• Pentose Sugar is Ribose• DNA has Deoxy Ribose• RNA has Ribose
Nucleosides-No Phosphate group
• Pentose Sugar + Nitrogen Base
Nucleotides
• Pentose Sugar + Nitrogen Base + Phosphate
Nucleotides join together to make Nucleic Acids
Sugar – Phosphate backbone
DNA is a double helix – 2 strands are complementary
1953
DNA Spooling
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