Macromolecules Molecules of Life
Learning Objectives know the difference between a dehydration synthesis reaction and a hydrolysis reaction know the different types of biological macromolecules be able to identify them know the role they play in biology
Lecture Outline 1. macromolecules and the reactions used to make and break them 2. the macromolecules
Macromolecules large molecules made up of smaller building blocks or subunits polymer: a long molecule made by repeating smaller units strung together monomer: the small units that make a polymer (not all macromolecules are polymers...)
Making polymers: Dehydration Syntheses requires cellular energy
Breaking polymers: Hydrolysis Reactions releases energy
Types of macromolecules Carbohydrates Lipids Proteins Nucleic acids
Carbohydrates ratio of atoms 1C : 1 H 2 O ex: glucose C 6 H 12 O 6 primary fuel for all cellular activity hydrophilic polar molecules types of carbohydrates monosaccharides polysaccharides
Carbohydrates: Monosaccharides the simplest of sugars; contain 3-7 C atoms C skeletons are used as raw material for manufacturing other organic molecules ex. glucose Usually in ring form in solution
Carbohydrates: Monosaccharides Glucose an incredibly important monosaccharide! in humans, most forms of carbohydrates converted to glucose in digestive tract glucose circulates in our blood and is... used immediately as energy for cellular activity stored temporarily as glycogen (in liver & muscle) converted to fat for long term storage
Carbohydrates: Polysaccharides polymers of monosaccharides made by dehydration synthesis; complex carbs as many as 10,000 joined monosaccharides two functions energy storage glycogen; in animals starch; in plants structural support cellulose; in plant cell walls ( fiber ) chitin; in insects, crustaceans, & cell walls of fungi
Making a polysaccharide: What type of biochemical reaction makes a polysaccharide?
Polysaccharides
Types of macromolecules Carbohydrates Lipids Proteins Nucleic acids
Lipids diverse group of compounds with one common trait: they are hydrophobic many more C-H bonds than carbs & contain significantly more energy *NOT a polymer, but a large molecule made up of 2 smaller molecules linked by dehydration synthesis types of lipids fats (triglycerides) phospholipids sterols/steroids
Lipids: Fats Structure: a glycerol backbone with fatty acid tails attached to it Formation: dehydration synthesis between a glycerol and fatty acid(s)
Lipids: Fats (triglycerides) 3 fatty acid chains linked to a glycerol molecule main function: energy storage also protection & insulation two kinds of fat unsaturated saturated (in reality, there is a range)
Monounsaturated & polyunsaturated fats
Phospholipids 1 glycerol, 2 fatty acids, and a phosphate group hydrophilic end (polar) and hydrophobic end (non-polar) on same molecule major component of cell membranes controls the flow of material into & out of cell
Forming the Phospholipid bilayer of a Cell Membrane Single Phospholipid Liposome Micelle Bi-layer Sheet
Lipids: Sterols/steroids help regulate growth & development carbon skeleton is 4 fused rings ex: cholesterol component in animal cell membranes starting material for other steroids, including sex hormones estrogen & testosterone Anabolic steroids can increase muscularity, but with serious health consequences: extreme aggression, high cholesterol and cancer
Types of macromolecules Carbohydrates Lipids Proteins Nucleic acids
Proteins chief building blocks of all life 1000s of different proteins enzymes (speed up chemical reactions) structural (connective tissue, hair, feathers, webs) contractile (muscle) defensive (antibodies) signal (hormones) receptor (in cell membrane) transport (delivers O 2 to muscles & tissues) all proteins are polymers of amino acid monomers
Amino acids central carbon atom with a general structure - a carboxyl group, an amino group & an R group (side chain/group) the R group determines the characteristics:
Amino acids, continued There are 20 R groups, therefore there are 20 amino acids which make up all proteins! Forming a Protein: proteins are formed by linking aminao acids together a peptide bond refers to a bond b/w 2 amino acids formed by dehydration synthesis between the carboxyl group of one AA and the amine group of another polypeptide = a chain of amino acids (which = a protein)
Making a protein by dehydration synthesis (or, break proteins down by removing an amino acid by hydrolysis)
Protein structure and function most proteins are globular in shape, structural proteins typically are fibrous shape is very specific to job if proteins lose their shape they cannot function properly, called denaturation caused by changes in ph excessive heat excessive salt concentrations
Types of macromolecules Carbohydrates Lipids Proteins Nucleic acids
Nucleic acids Nucleic acids form: DNA and RNA function: carry genetic information polymers of nucleotide monomers monomers can also function as energy carriers!» ADP, ATP, GTP made by dehydration synthesis
Nucleotide structure three parts 5 carbon sugar phosphate group 1 nitrogenous base cytosine guanine adenine thymine uracil
Part of a polynucleotide dehydration synthesis b/w the phosphate group of one nucleotide and the sugar of another called the sugar-phosphate backbone
Comparing DNA & RNA DNA deoxyribose nucleic acid double stranded (double helix) bases C, G, A, & T RNA ribonucleic acid single stranded bases C, G, A, & U
Summary: Biological macromolecules are made via dehydration syntheses and form carbohydrates, lipids, proteins & nucleic acids The most common chemical reactions involved in making macromolecules are the dehydration synthesis, hydrolysis reactions and hydrogen bonding Biomolecules form the energy storage systems, structural support features, information and communication networks of living organisms