700 likes | 712 Views
Macromolecules. Building Complex Molecules That Comprise Living Things. Comparison of Terms. Four types of organic macromolecules are important in living systems. Macromolecules: Polymers Made of Repeating Monomers. Organic Macromolecules Contain Carbon.
E N D
Macromolecules Building Complex Molecules That Comprise Living Things
Comparison of Terms Four types of organic macromolecules are important in living systems.
Organic Macromolecules Contain Carbon • Question: How many electrons does carbon need to fill its outer energy level? • Answer: Four Each carbon atom can make four covalent bonds with other types of atoms or additional carbons.
Dehydration Synthesis / Hydrolysis Dehydration Synthesis Hydrolysis
Carbohydrates: Structure • Simple • Monosaccharides= one sugar unit Glucose = blood sugar All cells use glucose for energy
CH2OH H HOCH2 O O H HOCH2 CH2OH O H H + O H H H HO H H HO OH H O H HO CH2OH HO CH2OH OH H HO OH HO H HO H HO H HO H Glucose + Fructose HO H Carbohydrates: Structure • Simple • Disaccharides = two sugar units Sucrose & Water
Carbohydrates: Structure • Simple • Disaccharides = two sugar units • Sucrose = glucose + fructose table sugar • Lactose = glucose + galactose milk sugar • Maltose = glucose + glucose seed sugar
Carbohydrates: Structure • Complex • Polysaccharides= many sugar units • Starch -- storage in plants • Glycogen -- storage in animals • Cellulose -- plant cell walls, indigestible • Chitin -- exoskeletons of insects, fungal cell walls
Carbohydrates: Functions • Energy source • Structural component • Cell-cell communication • C:H:O ratio 1:2:1
Carbohydrates: Dietary Recommendations • 58% of calories from carbohydrates • No more than 10% of calories from simple, refined sugars • Emphasize • Complex Carbohydrates • Starch • Fiber (cellulose) • Naturally-occurring simple carbohydrates • Fructose from fruit • Lactose from milk
Applying Your Knowledge • Which molecule consists of two sugar units? • Which choice best describes glycogen? • Which type of molecule provides the basic energy for your cells? • Which type of molecule is found in milk? • Monosaccharide • Polysaccharide • Disacharide
Lipids: Structure • Triglyceride—predominant form in diet • One molecule of glycerol • Three fatty acids • C:H:O ratio- 1:2:very few
Lipids: Structure • Types of Fatty Acids • Saturated – 2H per internal carbon • Unsaturated -- <2H per internal carbon one or more double bonds • Monounsaturated – one double bond • Polyunsaturated – more than one double bond
H H H H H H C H H H H C C C C C O O O OH OH OH C C C C C C O O O O O O OH OH OH C C H H H H C C H H H H C C H H H H C C C O O O H H H H C C H H H H C C H H H H C C H C H H C H H C H C C C C C C H H H H H H H H H H H H H H H H H H C C C H H H H H H C C C H H H H H H H H H HOH HOH HOH TriglycerideFormation Triglyceride Glycerol RemoveTheseWaters Add 3FattyAcids 3 Waters
Which Is a Source of Unsaturated Fatty Acids? Linseed Oil Beef Fat
Lipids: Structure • Phospholipid—component of cell membranes PolarHead Glycerol Fatty Acid Tails Hydrophilic Hydrophobic
Lipids: Structure • Steroids • Linked carbon rings • Natural body components • Hormones • Cholesterol
Estradiol Testosterone Steroids Cholesterol
Lipids: Functions • Concentrated energy source • Structural components of cell membranes • Phospholipids • Cholesterol • Communication • Steroid Hormones • Protection from water • Waxes Cholesterol Phospholipids
Lipids: Dietary Recommendations • < 30% of calories from lipids • < 10% of calories from saturated fats • Limit cholesterol to 300 mg/day • Avoid “trans” fatty acids in partially hydrogenated products • Emphasize • Unsaturated fatty acids from vegetables,fish, legumes,and nuts • Oils: mono- or polyunsaturated
Applying Your Knowledge • Which molecule is made of a series of carbon rings? • Which molecule has more than one double bond? • Which molecule has 2H for each internal carbon? • Which molecule has one double bond? • Polyunsaturated fatty acid • Cholesterol • Monounsaturated fatty acid • Saturated fatty acid
Proteins: Structure • Primary structure = chain of amino acids • Amino acids have common features Carboxylic AcidGroup AminoGroup R “Alpha”Carbon The “R” GroupDiffers for Each Amino Acid
Carboxylic Acid Group AminoGroup “Alpha”Carbon Amino Acids: Phenylalanine Structure Phenylalanine“R” Group
Carboxylic Acid Group AminoGroup Amino Acids: Leucine Structure Leucine “R” Group
Proteins: StructureForming the Protein Chain Phenylalanine Leucine Dehydration Synthesis between COOH & NH2
Proteins: StructureForming the Protein Chain The Peptide Bond Water Phenylalanine-Leucine Dipeptide
Four Levels of Protein Structure Tertiary(Folding by R-group interactions) Primary(Sequence) Quaternary(Two or more chains associating) Secondary(Coiling by Hydrogen Bonding)
Four Levels of Protein Structure Primary Structure = sequence of amino acids in chain
Four Levels of Protein Structure • Secondary Structure Folded structure due to hydrogen bonds between the amino and acid groups of amino acids N C N C H O H O or O H O H N C N C
Found in most proteins Found in silk
Four Levels of Protein Structure • Tertiary Structure: Three dimensional folded structure due to attractions and repulsions between R groups Can involve covalent bonding hydrogen bonding ionic interactions hydrophilic and hydrophobic interactions
StraightHair NaturallyCurlyHair |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| Hair Curling
Four Levels of Protein Structure • Quaternary Structure: Association of two or more protein chains eg. Hemoglobin is composed of 4 protein chains 2 are called alpha hemoglobin 2 are called beta hemoglobin
Proteins: Functions • Structural Component of Cells • Control of Metabolic Reactions: enzymes • Growth and Repair • Communication • Protein Hormones • Cell Receptors • Energy source • C:H:O ratio –no reliable ratio • For proteins Protein Protein
Proteins: Dietary Recommendations • 12% of calories from proteins • 8 essential amino acids obtained from • Lean sources of animal protein • Complementary plant proteins • Beans + Grains • Beans + Seeds
Applying Your Knowledge • Which structure results from hydrogen bonding? • Which structure involves an association of two or more protein chains? • Which structure describes the linear sequence of amino acids? • Which structure depends upon interactions between the R groups of the amino acids? • Primary • Secondary • Tertiary • Quaternary
Nucleic Acids • Nucleic acids store, transmit, and help express hereditary information • The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene • Genes are made of DNA, a nucleic acid made of monomers called nucleotides
Two Types of Nucleic Acids • There are two types of nucleic acids • Deoxyribonucleic acid (DNA) • Ribonucleic acid (RNA) • DNA provides directions for its own replication • DNA directs synthesis of messenger RNA (mRNA) and, through mRNA, controls protein synthesis • Protein synthesis occurs on ribosomes
1 DNA Figure 5.25-1 Synthesis ofmRNA mRNA NUCLEUS CYTOPLASM
1 2 DNA Figure 5.25-2 Synthesis ofmRNA mRNA NUCLEUS CYTOPLASM mRNA Movement ofmRNA intocytoplasm