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Concept 3: Biologically Significant Macromolecules. Biology Standard 3.5 Section 2.3. Key Idea:. Complex macromolecules are made of repeating units. Monomer. Monomer. Monomer. Monomer. Polymer. Organic Molecules. Living things = organic Organic = contains CARBON
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Concept 3: Biologically Significant Macromolecules Biology Standard 3.5 Section 2.3
Key Idea: Complex macromolecules are made of repeating units. Monomer Monomer Monomer Monomer Polymer
Organic Molecules Living things = organic Organic = contains CARBON Carbon is special- can form up to FOUR bonds, and can bond with itself H H H H C C C C H H H H H H
Carbon-Based Molecules • Many carbon-based molecules are chains of small subunits called monomers. • Monomers strung together make up polymers.
Carbon-Based Molecules • Most molecules that make up living organisms can be classified as macromolecules. • Macro- meaning large, big, or long. • Molecule- comprised of multiple atoms. • All biologically significant macromolecules can be classified into four categories: • Carbohydrates • Lipids • Proteins • Nucleic acids
Carbohydrates • Main Purpose = ENERGY • main source of fuel for cellular respiration • Starch = energy storage molecule in plants • Glycogen = energy storage molecule in animals • Additional Use = Structure/Support • Cellulose is used in plant cells (cell wall)
Carbohydrates • Monomers = monosaccharides (Ex. Glucose) • Polymers = polysaccharides (Ex. starch or cellulose)
Carbohydrates • Carbohydrates are initially synthesized by photosynthesis, or “production by light.” • When glucose is consumed, digestion breaks the bonds between the monomer units, making simple sugars that the body can absorb. • Eventually, sugars are absorbed by individual cells, and simple sugars are broken down through cellular respiration, resulting in ATP (the body’s energy “currency”). • Carbohydrates = 400 cal/g.
Lipids • Main Function = Long Term Energy Storage • Other Functions = cushioning organs, insulating the body, hormones, cell membrane • Made of glycerols (heads) and fatty acids (tails) Testosterone Estrogen
Lipids • Have more C-H bonds than carbohydrates (more bonds = more energy released when bonds are broken during digestion) • This means fats contain more calories than carbohydrates. Lipid = 900 cal/g. • Monomer = Fatty Acid • Polymer = ex. cholesterol
Lipids • Saturated (all single bonds) • Unhealthy fats • Solid at room temperature (butter, dairy) • No “gaps” so they pack together tightly and can clog arteries • Unsaturated (monounsaturated = one double bond, polyunsaturated = two or more double bonds) • Healthier fats • Liquid at room temperature (vegetable oil) • Double bonds provide “gaps” so these fats slide past each other and do not clog arteries
Proteins • Proteins are involved in almost every function of the human body. • When proteins are consumed, they are broken down into monomer units and recycled to suit the organism’s needs. • Proteins assemble and fold in different ways – STRUCTURE DETERMINES FUNCTION
Proteins • Proteins play a number of roles. • Transport proteins help move substances like oxygen throughout the body. (Can be embedded in cell membrane) • Structural proteins provide support, like keratin that forms hair or fingernails. • Hormone proteins carry out signaling around the body, like insulin regulating blood sugar. • Contractile proteins help control movement, like in muscle fibers. • Enzyme proteins work to accelerate the speed of chemical reactions.
Proteins • Monomer = amino acids • Polymer = polypeptides.
Proteins • About 20 different amino acids exist, 12 of which the human body can synthesize itself. • The others must be consumed from foods like beans, nuts, or meat.
Proteins • While proteins can be burned for energy, they represent a last resort. • Carbohydrates and lipids must both be exhausted before the body will use proteins for energy. • Proteins must first be converted to carbohydrates before they can be burned for energy. • Proteins = 400 cal/g. (same as carbs)
Proteins • While the instructions for building proteins are carried on DNA, proteins represent the finished structure, and carry out the functions of life. • Sometimes these functions can fail. • i.e. Sickle-cell anemia
Nucleic Acids Main Purpose = carry genetic information Polymers = DNA and RNA Monomer = Nucleotide Nucleotides are made of a sugar ring, a phosphate group, and a nitrogen-containing base (below). DNA – ATCG RNA – AUCG
Outside Carbohydrates Picture Lipids Picture Nucleic Acids Picture Proteins Picture Inside Subunit = ? Example = ? Function in the body = ? Subunit = ? Example = ? Function in the body = ? Subunit = ? Example = ? Function in the body = ? Subunit = ? Example = ? Function in the body = ?