Presentation on theme: "The Structure and Function of Macromolecules"— Presentation transcript:
1 The Structure and Function of Macromolecules Chapter 5
2 Macromolecules - larger molecules made from smaller ones. 4 major classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids.3 of these are polymers because they are made from individual building blocks called monomers.
3 Monomers - joined together through condensation or dehydration reaction (form macromolecules) Requires energy; uses covalent bonds (links together monomers)Water produced.
19 Lipids Lipids - no polymers (exception) Lipids nonpolar (no affinity for water)Fat made from glycerol and fatty acids.Glycerol - 3 carbon molecule with hydroxyl group and fatty acid; consists of carboxyl group attached to long carbon skeleton.
21 The 3 fatty acids in a fat can be same or different. No carbon-carbon double bonds, molecule is saturated fatty acid (hydrogen at every possible position)Form bad fats - solid at room temperature (butter, lard)
25 Purpose of fat - energy storage. Gram of fat stores 2X as much energy as gram of polysaccharide.Fat also cushions vital organs.Layer of fat can also function as insulation.
26 Phospholipids - 2 fatty acids attached to glycerol, phosphate group at 3rd position. Fatty acid tails are hydrophobic, phosphate group and attachments form hydrophilic head.When phospholipids added to water, self-assemble with hydrophobic tails pointing toward center, hydrophilic heads on outside.
33 ProteinsProteins - support, storage, transport, defenses, and enzymes.Made in ribosomes in cell.Proteins - amino acids linked together to form polymer.20 different amino acids that can be linked together to form thousands of different proteins.
34 Amino acids link - polypeptides - combine to form proteins. Amino acids made of hydrogen atom, carboxyl group, amino group, variable R group (or side chain).R group makes amino acids different from one another.
48 Protein’s shape can change due to environment. pH, temperature, or salinity (salt concentrations) change - protein can denature (starts to fall apart)Some proteins can return to functional shape after denaturation, others cannot, especially in crowded environment of cell.
53 Monomers of nucleic acids - nucleotides. Nucleotides made up of 3 parts: nitrogen base, five-carbon sugar, and phosphate group.Nitrogen bases, rings of carbon and nitrogen, come in 2 types: purines and pyrimidines.
61 DNA used to show evolutionary similarities between species. Two species that appear to be closely-related based on fossil and molecular evidence also more similar in DNA and protein sequences than more distantly related species.