Biochemistry Notes - Topic 2-1 to 2-3 PDF

Topic Two: Biochemistry Carbohydrates Lipids Proteins Nucleic Acids  Four Types of Organic Molecules There are 4 major types of organic molecules important in biology. Proteins Primary,...

Topic Two: Biochemistry Carbohydrates Lipids Proteins Nucleic Acids  Four Types of Organic Molecules There are 4 major types of organic molecules important in biology. Proteins Primary, Secondary, Tertiary, Quaternary Nucleic Acids Carbohydrates DNA, RNA monosaccharides, disaccharides, Lipids polysaccharides Triglycerides, Phospholipids, Waxes, Steroids 2  Metabolism Metabolism: All the chemical reactions that occur in the body. – Can be catabolic or anabolic – Over 200,000 reactions occur in your body cells Monomers are basic subunits used to build larger molecules. – Eg. Amino acids Polymers are molecules composed of many monomers bonded together – Eg. Many amino acids bond together to form a protein. 3  Catabolic vs. Anabolic Reactions Catabolic Reactions: Anabolic Reactants: Larger molecules Small units (monomers) (polymers) break down combine to make larger into smaller units molecules (polymers) (monomers) Ex. Plants and Ex. Digestion (breaking photosynthesis down food) 4  Catabolic Monomers Polymers Reactions Anabolic Reactions  Hydrolysis “water” “to cut” Larger molecule is broken down using water Water is taken up at the broken bond site + H2O 6  Dehydration Synthesis “To take water out” “To make” Larger molecules are formed by removing water + H2O 7  Catabolic vs. Anabolic Reactions How to Remember these terms: CHAD: Catabolic – Hydrolysis, Anabolic – Dehydration Synthesis 8 Natural Polymers 9 Human-made Polymers 10 Biomolecules by the Amoeba Sisters 8:12 https://www.youtube.com/watch?annotation_id =annotation_3541811209&feature=iv&src_vid= Ptmlvtei8hw&v=YO244P1e9QM  Topic 2-2: Carbohydrates CHO Carbohydrates are the body’s most important source of energy! The human body cannot make carbohydrates itself We must consume plants for carbohydrates. 12  Characteristics of Carbohydrates A carbohydrate can be a single sugar or polymer of many sugars Carbohydrates are composed of carbon (C), hydrogen (H), and oxygen (O) – Ratio of carbon, hydrogen, oxygen = 1:2:1 – Ex. Glucose C6H12O6 13  Two Purposes of Carbohydrates Structural Major structural component of cell organelles, membranes, cell wall Ex. cellulose Energy Produced by photosynthesis, carbohydrates are the major energy source for cells. Energy is released through cell respiration 14  Types of Carbohydrates Monosaccharides Classified by the “1 sugar unit” number of sugar Ex: glucose/fructose units they contain Disaccharides “2 sugar units” Ex: sucrose Polysaccharides “many sugar units” Ex: starch/ glycogen 15  Carbohydrates How are disaccharides and polysaccharides formed? Dehydration Synthesis!! + H2O  Monosaccharides Monosaccharides are made of single sugar units Examples include: – glucose – fructose – These are all isomers Same chemical formula C6H12O6 17  Use the chart to help fill in your workbooks Monosaccharide Origin Purpose From food, found in Main source of Glucose human blood plasma fuel for cells + all cells Fructose Found in fruits and Sweetest naturally honey. Twice as occurring sweet as glucose carbohydrate. Used for sweeteners. 18  Disaccharides Formed by the joining of two monosaccharides – Process called dehydration synthesis (water molecule is extracted from the two monosaccharide sugar molecules that come together) Disaccharides: aka double sugars!!! 19  Disaccharides - Sucrose  Ex: glucose + fructose make sucrose and water  The reverse process is called HYDROLYSIS (uses water) 20  A Common Disaccharide Disaccharide Monomers General comments (ISOMERS) Glucose + Fructose From sugar cane Sucrose plant, used as table sugar What sugar does to your body (3:31): https://youtu.be/Yda8RtOcVFU 21 Polysaccharides: also known as Complex Carbohydrates 22  Polysaccharides Formed by the union of many monosaccharides by dehydration synthesis Major Role a) Energy Storage  energy storage molecles in organisms are  starch (plants)  glycogen (animals) liver 23  Polysaccharides Major Role b) Structural Support  such as cellulose (plants) and chitin (exoskeletons) 24  Important Polysaccharides What are the two important polysaccharides used for energy storage in organisms? STARCH (PLANTS) and GLYCOGEN (ANIMALS)  Starch Monomers used: Starch is multiple subunits of glucose Function: Energy storage molecule in plants Other: Glucose molecules formed during photosynthesis that are not required for growth or energy in the cell are linked together to form starch 26  Glycogen Monomers used: Branched chains of glucose Function: Storage of glucose in animals (liver and muscle cells) High Blood Glucose -Glycogen formed in the liver Low Blood Glucose -Glycogen is broken down Other: When energy is needed by the cell, stored glycogen is broken down into glucose molecules to be used for Darker meats mean most energy of the stored glycogen has broken down into lactic acid 27  Glycogen Monomers used: glucose Function: Storage of glucose in animals (liver and muscle cells) – High Blood Glucose -Glycogen formed in the liver – Low Blood Glucose -Glycogen is broken down Other: When energy is needed by the cell, stored glycogen is broken down into glucose molecules to be used for energy 28  Cellulose Monomers used: glucose Function: Main structural material in plant cell walls Other: The bonds between the glucose molecules are difficult to break, so cellulose is not easily digested. – Cotton, wood and wood products like paper are almost entirely made of cellulose! – Digestion in cows, horses, goats and termites is done by microorganisms that live in their digestive tracts 29  Why can’t we digest cellulose?? Humans don’t have cellulase – an enzyme to break down cellulose) But… we still need cellulose (aka fiber) to hold water in the large intestine, and help eliminate wastes 30  Chromebook Activity on Carbohydrates http://www.tv411.org/sci ence/tv411-whats- cooking/carbohydrates- science-lesson  Topic 2-3: Lipids CHO Lipids are insoluble (do not dissolve) in water Contains carbon, hydrogen, and oxygen Ratio of H to O is greater than 2 to 1 Examples include – triglycerides – phospholipids – steroids 33  Long Term Energy Storage Purposes of – Lipids are long term energy storage molecules Lipids contain more than twice the calories compared to carbohydrates or proteins Structural Material – cell membranes – cushion for organs – carriers for vitamins – raw materials for synthesis of hormones – insulators 34  Types of Lipids: Triglycerides Triglycerides – Commonly known as fat – Formed from one glycerol and 3 fatty acids by dehydration synthesis O Fatty Acid glycerol O Fatty Acid Triglyceride (fat) O Fatty Acid Total = 3 waters produced  2 Types of Fatty Acids: SATURATED FAT – Source: usually from animals – Single/double bond: only single bonds between carbon atoms – Reactivity: Very Stable -- hard to break down – Solid/liquid: solid or semi- solid at room temperature – Example: butter 36  Types of Fatty Acids UNSATURATED FAT Source: usually from plants Single/double bond: unsaturated fatty acids have some double bonds between carbon atoms Reactivity: more reactive than fats and easy to break down Solid/liquid: liquid at room temperature Example: Canola oil Bill Nye- Fat is bad. Fruit, veg good 1:53 – 3:23 http://www.youtube.com/watch?v=YlCX2NCEgcM&sa Bill Nye- clots 4:30 – 6:18 fety_mode=true&safe=active http://www.youtube.com/watch?v=RiYOu ASAP Science – butter vs. margarine 3:09 I7iyp8&safety_mode=true&safe=active https://www.youtube.com/watch?v=KG_ybdk1VaE  Types of Lipids: Phospholipids Phospholipids are a major component of cell membranes Formed from one glycerol, two fatty acids and one phosphate O Fatty Acid glycerol O Fatty Acid O Phosphate 39  Cell Membrane Hydrophilic Hydrophobic – Phosphate replaces one of the fatty acids Phosphate is hydrophilic (polar) Fatty acid tails are hydrophobic (nonpolar)  Types of Lipids: Steroids Structure = four fused carbon rings Function = building material for hormones, bile etc Common examples are cholesterol and testosterone https://youtu.be/Hxq6xCa8Dm8 42 Effects of Steroids 43  Assignment Read: “The Cholesterol Controversy” Answer questions 1 – 5 in your workbook 44  Cholesterol Controversy 1. What is Cholesterol? A lipid molecule made in the liver. Used in cell membranes & hormones. 2. What diseases are cholesterol associated with? levels in the blood are associated with atherosclerosis, gall stones and heart disease! People with a certain genetic makeup are predisposed to arteriosclerosis…Can lead to heart disease!!!!! Atherosclerosis 45  LDLs vs. HDLs 3. What do HDL and LDL stand for? HDL = High Density Lipoprotein, LDL = Low Density Lipoprotein 4. What is the function of HDL’s and LDL’S? Low-density lipoprotein is the major cholesterol carrier in the blood LDL’s are “bad cholesterol” High levels of LDLs have been associated with the clogging of arteries known as a plaque. Plaque restricts blood flow to the heart + brain & can lead to heart attack or stroke. 46  State the function of HDLs & LDLs HDLs (which are good!) carry LDLs back to the liver, which begins breaking it down High density lipoproteins lower blood cholesterol eating a balanced diet, exercising, and stopping tobacco use, medications can increase HDLs!! 47  Cholesterol & Diet People get cholesterol in two ways – The liver produces cholesterol – Foods contain cholesterol – especially egg yolks, meat, poultry, fish, seafood and whole-milk dairy products Typically the body makes all the cholesterol it needs (no need to consume) What increases blood cholesterol? – Consuming saturated fatty acids – Eating trans fats – Both may lead to heart disease 48  Cholesterol & Diet 5. How can you decrease your cholesterol intake? Reduce intake of saturated fats Eat lean meat, fish and poultry and use fat-free and low-fat dairy products vegetable sources such as beans are good substitutes for animal sources of protein 49 5. How can you decrease your Cholesterol cholesterol? (continued) Exercising lowers LDLs & Exercise Being overweight tends to increase the amount of low-density lipoprotein (LDL) in your blood. Fibre and cellulose lower LDLs Higher intensity exercise lowers the LDLs more than moderate exercise does. It also raises HDLs more. NOTE: Genetics, weight, age, sex, and diet all contribute to an individual's cholesterol profile. 50 Bozeman Triglicerides video http://www.youtube.com/watch?v=VGH D9e3yRIU Mr. Bean eating competition https://www.youtube.com/watch?v=jxM YcIZstCk 51