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Macromolecules. Ch 3.3-3.20. In- Macromolecules . Today we will begin discussing the four classes of macromolecules: Carbohydrates, lipids, proteins and nucleic acids. Give two to three examples of each type of macromolecule. Functional Groups.
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Macromolecules Ch 3.3-3.20
In- Macromolecules Today we will begin discussing the four classes of macromolecules: Carbohydrates, lipids, proteins and nucleic acids. Give two to three examples of each type of macromolecule.
Functional Groups • All the functional groups we have learned are polar • The functional groups attach themselves to carbon skeletons and exhibit their chemical properties. • They are usually the direct participants in chemical reactions.
Making large molecules • Monomer-fundamental molecular unit. • Polymers- macromolecules made by linking together several monomers • Each of the macromolecules we will discuss are constructed of monomers strung into polymers
Dehydration Synthesis • Molecules synthesized by the loss of a water molecule between monomers • Builds polymers
Hydrolysis • “breaking apart with water” • Breaks down or degrades a polymer
Four Classes of Macromolecules • Carbohydrates • Lipids • Proteins • Nucleic Acids
Carbohydrates • The word “carbohydrate” indicates that these compounds are made of carbon and water (hydrates). • Monosaccharide is the simplest carbohydrate (monomers) • (CH2O)n – general formula for monosaccharide
Monosaccharides • “-ose” indicates sugar (fructose, glucose, etc) • In solution, many monosaccharides form a ring shaped molecule. • The basic role of simple sugars are as fuel to do work, as raw material for carbon backbones, and as monomers from which disaccharides and polysaccharides are synthesized.
How sweet it is… • Humans are born preferring sweet tasting foods and consume, on average in the US, 125 pounds per person per year. • There seem to be important biological reasons for this predilection from the standpoint of both animals and plants. What might they be?
Polysaccharides • Using glucose as a monomer, different organisms build several polymers. • Starch, glycogen and cellulose are all polysaccharides
Polysaccharides How are each of the polysaccharides made? Dehydration Synthesis How are they broken down? Hydrolysis
Starch • Used for long term energy storage in plants. • Helical and may be branched (amylose) or un-branched (amylopectin) • Animals can hydrolyze the polymer to obtain glucose.
Glycogen • Used for long term energy storage only in animals. • Can by hydrolyzed to obtain glucose • Several branches. Why?
Cellulose • Principal structural molecule in the cell walls of plants and algae. • Different bonds between monomers than starch or glycogen. Forms linear polymers that are cross linked with other chains • Animals cannot hydrolyze this polymer for energy, only certain bacteria, fungi and protozoan's. What about cows? • Also known as fiber
Out - Carbohydrates Construct a table that summarizes the information we have discussed about carbohydrates. Remember to include names of monomers, polymers, uses, types, where they are found, shape, etc
In- Lipids Fats are lipids. What is the difference between saturated and unsaturated fat in physical appearance and molecular structure? Give examples of each type of fat.
Lipids • Fats Oils, waxes, steroids • Serve primarily as energy storage • Predominantly carbon and hydrogen, fewer oxygen. • (CH2)n
Lipids-Structure • Polymers of glycerol and fatty acid chains • Formed by dehydration synthesis reactions
Unsaturated *double bonds in fatty acid chains *liquid at room temperature *flexible, do not pack into globules *plant fats Saturated *single bonds between C *solid at room temp *pack together into large globules *animal fats Unsaturated vs. Saturated Fats
Other types of Lipids • Phospholipids-major component of cell membrane. Glycerol head, two fatty acid “tails” • Waxes – hydrophobic coatings formed by organisms to ward off water. Fatty acid linked to an alcohol. • Steroids- an example of which is cholesterol, responsible for the breakdown of fats and the production of sex hormones.
Out Lipid model construction
Proteins • Proteins are essential to the structures and activities of life • Structure, defense, contractile, storage, transport, signaling, catalyst. • Structure of the protein determines function • Constructed from amino acids
Proteins-Amino Acids • Only 20 kinds of AA make all of the proteins in living things • Central carbon atom covalently bonded to one hydrogen, one amino group, one carboxyl group, and one other chemical group (R) • The R group gives the AA its properties
Amino Acids • Linked by peptide bonds (dehydration synthesis) that form a chain called polypeptide • Chain is then folded into a specific shape • The shape of the chain determines the function of the protein
Primary Primary Secondary Tertiary Quaternary
Protein Structure • Primary -amino acid sequence -changes in primary structure affect overall structure
Protein Structure • Secondary • Polypeptide coiling or folding • Produced by hydrogen bonding between –NH and –C=O groups of AA along chain • Alpha helix or pleated sheet
Protein Structure • Tertiary -Overall shape of the polypeptide -results from the clustering of hyrophobic/hydrophilic R groups as well as ionic and hydrogen bonding between R groups.
Protein Structure • Quaternary • Relationship btwn multiple polypeptides of a protein • Many (but not all) proteins consist of more than one primary chain. - Mostly hydrogen bonds
Nucleic Acids • Information-rich polymers of nucleotides • Store genetic information • DNA nucleotide sequences (genes) code for the production of proteins
Nucleotides • Three functional parts: phosphate group, 5 carbon sugar, nitrogenous base • 5 types: Adenine, Guanine, Cytosine, Thymine in DNA. Uracil in RNA instead of Thymine.