Chapter 2: Organic Molecules (Macromolecules) - PDF

# Organic Molecules (Macromolecules) | Polymers | Monomer | |-------------------|-------------| | 1. Lipids | Lipids | | 2. Carbohydrates | Sugars | | 3. Nucleic Acids | DNA | | 4. Proteins | Amino Acids | ## Hydrolysis & Dehydration Synthesis - Dehydratio...

# Organic Molecules (Macromolecules) | Polymers | Monomer | |-------------------|-------------| | 1. Lipids | Lipids | | 2. Carbohydrates | Sugars | | 3. Nucleic Acids | DNA | | 4. Proteins | Amino Acids | ## Hydrolysis & Dehydration Synthesis - Dehydration: loss of a water molecule to assist bond formation - Hydrolysis: addition of a water molecule to assist bond formation ## Carbohydrates 1. **Monosaccharides** 2. **Disaccharides** 3. **Polysaccharides** Examples: Sugars, starch, cellulose, glycogen, chitin (consists C + H + O) ### Monosaccharides - Pentoses: DNA & RNA - Hexoses: Glucose, fructose, galactose #### Ketoses - Contains ketone (fructose) #### Aldoses - Contains aldehyde (glucose, galactose) ### Disaccharides - 2 monosaccharides joined together through dehydration synthesis (glycosidic linkage). - Glucose + Glucose = maltose - Glucose + Galactose = lactose - Glucose + fructose = sucrose ### Polysaccharides - Polymers of glucose (storage purposes, energy currency) - 2 types 1. **Starch:** Plant cells 2. **Glycogen:** Human cells # Lipids (Macromolecules) - They're Hydrophobic - Less oxidized than sugars; lots of chemical energy - Dissolves in alcohol & acetone ## Types of Lipids 1. **Triglycerides:** 3 fatty acid + glycerol 2. **Phospholipids:** Phosphates + lipids (2 fatty acids + glycerol backbone) 3. **Steroids** ### 1. Triglycerides (Neutral Fats) - Neutral charge - Fats in animals, oil in plants - Large polymers constructed from two kinds of molecules 1. Compact energy storage 2. Insulation 3. Cushions internal organs #### Fatty Acids (Carbon bonds are present) - Hydrophilic head; hydrophobic tail - **Saturated:** no double bonds, solid at room temperature (in animal fat), very unhealthy - **Unsaturated:** contains one or more double bonds, liquid at room temperature (in plants) - **Trans Fat:** oils that have been solidified by addition of hydrogen atom at the sites of double bonds (margarines) - **Omega-3 fatty acids:** found in cold-water fish, decrease risk of heart disease ### 2. Phospholipids (Lipids + Phosphates) - 2 chains of fatty acids + glycerol backbone + phosphate group - Polar head + non polar tail (negative charge) - Important structural component of cell membrane - Keeps water at a stable condition in the cell membrane ### 3. Steroids - Flat molecules - a presence as a carbon skeleton consisting 4 interconnected rings - **Cholesterol:** it's the precursor of all steroid hormones (they regulate membrane fluidity) - Helps in the formation of sex hormones ## Neutral Fats - Location: Fat deposits - Functions: Protect & insulate the body organs - Source of stored energy ## Phospholipids - Location: Cell membrane & abundant in brain & nervous tissue - Functions: - Transport of lipids in plasma - Help to form insulating white matter ## Steroids - **Cholesterol**: basis of all body steroids - **Bile Salts**: - Location: Released by the liver - Function: Aids in fat digestion ## Vitamin D - Location: Produced in the skin on exposure to UV - Function: Necessary for normal bone growth and function. ## Sex Hormones - **Estrogen & progesterone** (female hormones) - **Testosterone** (male hormones) - Function: Necessary for normal reproductive function - Deficits result in sterility ## Corticosteroids - **Glucocorticoid:** - Function: Aldosterone helps regulate salt & water balance, targeting the kidneys. # Lipid Types ## Vitamin A - Location: Found in orange-pigmented vegetables - Function: Part of photoreceptor pigment involved in vision ## Vitamin E - Location: Taken in via plant products (wheat germ, green leafy vegetables) - Function: - Promote wound healing & contribute to fertility - An antioxidant; helps neutralize free radicals (triggers some types of cancer) ## Vitamin K - Location: Made available largely by the action of intestinal bacteria - Function: Necessary for proper clotting of blood ## Prostaglandins - Location: In cell membrane - Functions: - Stimulation of uterine contractions (labor & abortions) - Regulation of blood pressure - Helps in movement of food in gastrointestinal tract ## Lipoproteins - Location: Blood stream - Function: Transports fatty acids and cholesterol in the bloodstream (HDLs & LDLs) ## Glycolipids - Location: Components of cell membranes - Function: - Determines blood type - Plays a role in cell recognition or recognition of foreign substances # Proteins - Monomer: Amino Acids - Consists of an asymmetric carbon bonded to 4 different covalent patners: 1. Amino Group: basic part 2. Carboxyl group: Acidic part 3. Hydrogen atom 4. R (side chain group): makes each amino acid/protein different ## Structural Levels of Proteins 1. **Primary Structure:** - Binds with polypeptide bonds - The number & location of amino acids determine how the proteins function 2. **Secondary Structure:** - Alpha helix: coiled structure supported by hydrogen bonds - Beta pleated sheets: folded structure also supported by hydrogen bonds 3. **Tertiary Structure:** (3-dimensional) - Coils more by the bonding of R groups together 4. **Quaternary Structure** - Completed structure of 2 or more polypeptide chains binding - The complete formation is all connected with hydrogen bonds ## Types of proteins based on shape/function 1. **Fibrous proteins:** known as structure proteins. Could be secondary or quaternary. - Ex: collagen (in bones & tendons) - Keratin (skin, hair, and nails) 2. **Globular proteins:** (functional proteins) - Compact spherical molecules, water soluble - Enzymes, hemoglobin, antibodies, hormones, signaling receptors. - Specific pH & temperature is required in order for the protein not to denature - Ex: hemoglobin loses function when pH is acidic - Pepsin become inactivated when the pH becomes alkaline. ## Different proteins & their functions: - **Antibodies (immunoglobulins)** - Proteins that recognizes foreign substances and fights them off (inactive bacteria, toxins, viruses) - **Hormones:** help regulate growth and development (produced by glands) 1. Growth hormones 2. Insulin: helps regulate blood sugar levels 3. Nerve growth factor: guides the growth of neurons in the development of the nervous system - **Transport Proteins:** - Hemoglobin transports oxygen in the blood - Other transport proteins in the blood (carries iron, cholesterol - lipoproteins, etc.) - **Enzymes (biological catalysts)** - Slowing down activation energy & speeds up chemical reactions. - Ex: hydrolase, polymerase, and phosphatase - **Structural Proteins:** (ex: collagen) - **Storage Proteins:** (ex: ovalbumin) - **Transport Proteins:** (en: O2 by hemoglobin) - **Hormonal Proteins:** (insulin, glucagon) - **Receptor Proteins:** (neurotransmitter receptors) - **Defense Proteins:** (Antibodies) - **Enzymatic Proteins:** (speeds up reactions) # Nucleic Acids (DNA & RNA) ## DNA 1. Deoxyribose sugar (absence of 1 oxygen) 2. A double helix 3. Adenine, guanine, cytosine, and thymine ## RNA 1. Ribose sugar 2. Single stranded 3. Adenine, guanine, cytosine, uracil 4. 3 types: mRNA, rRNA, tRNA ## Structure of nucleic acids: - Made up of nucleotides - (pentose sugar + nitrogenous base + phosphate group) - Pentose sugar + phosphate group = backbone ## Types of nitrogenous bases: 1. **Purines:** (double ring structure) - Adenine - Guanine 2. **Pyrimidines:** (single ringed structure) - Thymine, cytosine, uracil ### DNA - Adenine + Thymine (A=T) → 2 hydrogen bonds - Cytosine + Guanine (C=G) → 3 hydrogen bonds ### RNA - Adenine + Uracil (A=U) - Cytosine + Guanine (C=G) ## ATP (adenosine triphosphate) - Energy currency - 6CO2 + 6H2O → C6H12O6 + 6O2 - We consume glucose - Glucose metabolism (cellular respiration) - 6CO2 + 6H2O + ATP - The break down of ATP to ADP releases energy