Organic Molecules Carbohydrates, Proteins, Lipids and Nucleic Acids NC Essential Standard Bio.4.1

Organic Molecules Large compounds or macromolecules that contain carbon Required by all living things 4 Organic Molecules: Carbohydates, Lipids, Proteins, and Nucleic Acids All form polymers: chains of subunits How do we get these molecules?

Carbohydrates Composed of Carbon, Hydrogen and Oxygen Ratio: 1:2:1 (always 1 C: 2 H: 1 O) Collectively called SUGARS Importance: Main source of ENERGY for your body! Cells convert the carbs you eat into energy the cells can use!

Carbohydrates Formation of sugars (into polymers): Condensation/dehydration reaction Produces water Breakdown of sugars: Hydrolysis reaction Requires water 3 Classifications of Carbohydrates: Monosaccharides, Disaccharides, Polysaccharides

Monosaccharides: 1 sugar “simple sugars” Consists of 1 sugar subunit Ex.: glucose, fructose (fruit), galactose (milk) Glucose the primary energy source for cells Made by plants during photosynthesis “blood sugar” in the human body

Disaccharides: 2 sugars Sugar made of two monosaccharides Examples: sucrose — common table sugar = glucose + fructose lactose — major sugar in milk = glucose + galactose Serve as energy storage Form of glucose transfer in the body

Polysaccharides: Many sugars Sugar made of more than two monosaccharides 3 polysaccharides Starch – glucose storage in plants; branched polymers pasta, grains, rice, potatoes Glycogen – glucose storage in animals; highly branched polymers Provide glucose to blood when needed; energy for muscles Cellulose – found in plant cell walls; organized ‘chain-linked fence’ polymers Provides structure and support in plants Fiber!!! – humans can’t digest this; improves bowel function

Whole Grains vs. Refined Grains Why are whole grains better for you than refined grains (processed white flour) Processing to make white flour removes many of the nutrients and fiber from the grain Leaves behind only the starchy part “enriched white flour” – has some nutrients added back synthetically

Carbohydrates in your diet Monosaccharides: simple Glucose, quick energy - enter the bloodstream fast Candy, honey (fructose), fruits Polysaccharides: complex Polymers, take time to break down and enter bloodstream, more sustained energy; fiber (whole grains)! Starches: Pasta, cereal, breads Ex. Runner’s diet

Glucose in your body Human body requires a steady amount of glucose daily – fuel/energy for the body! We don’t eat bits of food all day long Insulin – hormone secreted by the pancreas; removes glucose from blood and sends it to cells of liver, muscles, and fat so that it can be used or stored (as glycogen) Diabetes: improper regulation of blood sugar (glucose); causes high blood sugar Body does not make enough insulin or does not respond to it normally

Lipids Organic compounds that have much less oxygen than carbohydrates Referred to as fats and oils Ex. Beef fat: C57H110O6 Insoluble in water because they are non-polar Used by cells for energy storage, insulation (adipose tissue), protective coating, cell membrane function

Types of Lipids 2 Main Types of lipids: Phospholipids Key components in cell membranes Control movement of materials in and out of cells Triglycerides: We consume these!!! Source of energy; contain more energy than other organic molecules Can be Saturated or Unsaturated

Triglyceride Structure

Triglycerides Unsaturated Fats Contain double bonds on the fatty acid chains Not “saturated” with Hydrogen Kinked molecules; not linear Example: olive oil, vegetable oil, etc.; usually liquids Benefits when used in moderation: Can reduce cholesterol and cardiovascular risks

Triglycerides Saturated Fats Contain single bonds between the carbons of the fatty acid chain “Saturated” with Hydrogen, as much as it can hold linear molecules Ex. Steak fat, butter fat, usually solid (animal derived)

Triglycerides Problems with too many saturated fats: Don’t really need them in diet; body makes what it needs Can increase “bad” cholesterol Fat can build up on arteries; atherosclerosis Can increase risk of cardiovascular disease

Proteins Most abundant organic molecule of the body! Composed of C, H, O, N and sometimes S Amino Acids are the building blocks of proteins. 20 amino acids found in nature. Amino acid polymer order determines the type of protein. *DNA code determines polymer order!!! Peptide Bond: The covalent bond found between two amino acids to create an amino acid polymer Protein polymers are called “polypeptide chains”

Proteins Importance Tissue Building! Keratin: Hair, Fingernails; Exoskeletons Hemoglobin: Carry O2 in blood Insulin: lowers blood sugar; helps it get stored as glycogen; other hormones too Antibodies: help provide immunity, etc. ENZYMES Proteins that make it easier for a reaction to take place

Proteins - Enzymes Enzymes Make it easier for reactions to occur Act as catalysts to speed up a reaction They lower the activation energy (energy necessary for the rxn. to occur) Lock and Key Model Makes enzymes only work for specific reaction Important in controlling reactions of the body Ex.: amylase, catalase, lactase “Enzymes are proteins that end in –ase”

Enzyme Structure – Lock and Key

Denaturing Proteins Denature: when the shape of the protein gets permanently changed Enzyme can’t function any longer Caused by: change in pH or temp Cold = usually slows enzymes down Hot = denatures enzymes Too acidic or basic = usually denatures enzymes *Important to maintain homeostasis!

Denaturing Proteins

Nucleic Acids complex macromolecules that stores cellular info. in the form of a code. Made up of smaller subunits called nucleotides. Composed of C, H, O, N, P atoms Can contain the information necessary to synthesize proteins.

DNA DNA: DeoxyriboNucleic Acid. A master copy of an organism’s genetic information Double helix shape Strands of DNA form genes, which are the components of chromosomes. RNA: RiboNucleic Acid. Helps in the formation of DNA and many proteins. Not a double helix – single strand