Structure and Function of Macromolecules

Four Main Types of MacromoleculesMacromolecules are constructed of smaller units repeating units called monomers CarbohydratesLipidsProteinsNucleic Acids

Making and breaking of polymers:

1. Making polymersDehydration SynthesisLosing a water molecule to join two monomers together.Anabolic reactionBuilding polymers2. Breaking PolymersHydrolysisWater molecules break polymers apart.Catabolic reactionBreaking down polymers

Carbohydratesmonomer monosaccharides known as simple sugars Disaccharide All have a ratio of 1:2:1 ratio of C:O:HCH2O

Monosaccharides:

Examples: pentose sugars. 5 carbons. RiboseDeoxyribose Ribulose hexose sugars 6 carbons Glucose,Galactose Fructose. Typically ring shaped in aqueous environments like the cell.

Disaccharides: These are double sugars with the formula C11H22O11

PolysaccharidesThe basic formula is ( C6H10O5)n . These are macromolecules capable of acting as structural or storage molecules.

PolysaccharidesComposed of repeating glucose molecules.StorageStarchFound in plants rootsBulky moleculeGlycogenFound in liver of animalsMore compact

Structural PolysaccharidesCelluloseFound in plant wallsCannot be digested by animalsChitinOnly carbohydrate containing nitrogen.Found in insect shells

Structural Polysaccharides:

Fats are composed of: Glycerol3 carbon alcohol3 fatty acid molecules

Saturated Verses Non-Saturated

Saturated or Unsaturated?Saturated fatty acidsSingle bond between carbons.Found in animalsTypically solids at room temperature: Lard, butterUnsaturated fatty acids Contain one or more double bonds between the carbons. Double reduces the number of hydrogens that that can be attached to the carbon in the molecule. This causes the molecule to bend or kink at each of the double bond sites. Found in plantsTypically liquids at room temperature: vegetable oil

Saturated vs UnSaturated LipidsLipids: A group of polymers that have one characteristic in common, they do not mix with water. They are hydrophobic. Some important groups are fats, phospholipids, and steroids.

Lipids

Provide insulationServes as an energy storage source 1g.=9 Kcal of energyShock absorber for internal organs. Steroids and sex hormones are made from fats.

Phospholipids:Structurally related to fats but contain 2 fatty acids and one molecule of phosphate. These molecules are found making up the plasma membrane of cells. Amphipathic They exhibit a polar and non polar quality.The phosphate group is hydrophilic while the fatty acid area is hydrophobic.

Steroids:Lipids characterized by a carbon skeleton of 4 fused rings.Cholesterol is an important steroid found in all animal tissue. Plants do not contain cholesterol. Cholesterol is a precursor to steroidsCholesterol adds fluidity to membranes. Animals that live in cold climates have more cholesterol and unsaturated fatty acids in their membranes

Cholesterol

Proteins:

macromolecules that make up 50% of the dry weight of most cells.

Types of proteins:1. Structural ( support) examples: elastin, collagen, and keratin 2. Storage food source, examples: ovalbumin and casein 3. Transport moves other substances, examples: hemoglobin and cell membrane proteinsHormonal coordinates bodily activities, example insulin, 5. Contractile movement, examples: actin and myosin 6. Antibodies defense,examples: Ig.E, IgA, and Ig.G 7. Enzymes aid in chemical reactions,examples: amylase and proteases

Amino Acids:Most amino acids consist of an asymmetrical carbon bonded to an, amino group, hydrogen, an R group,and a carboxyl group.

Amino Acids:

Most amino acids consist of an asymmetrical carbon bonded to an, amino group, hydrogen, an R group,and a carboxyl group.

Protein conformation:refers to the three dimensional shape of a protein molecule. This shape is important to its function. If the conformation is changed, even slightly , then the function of the protein changes.

Nucleic Acids ( DNA and RNA)Nucleotides: monomers that come together to form a nucleic acid. They contain either a ribose or deoxyribose sugar ( ribose has one more oxygen in its molecule), a phosphate and a nitrogen base

DNA Base pairing rules.

DNA