KIN 267 Winter 2025 Chapter 2 (Students) PDF

Chapter 2 The Chemical Level of Organization This slide deck contains animations. Please disable animations if they cause issues with your device. Chemical Reactions Chemical reactions occur when new bonds are formed or old bonds are broken Reactants – starting substances Products – e...

Chapter 2 The Chemical Level of Organization This slide deck contains animations. Please disable animations if they cause issues with your device. Chemical Reactions Chemical reactions occur when new bonds are formed or old bonds are broken Reactants – starting substances Products – ending substances Metabolism Forms of Energy & Chemical Reactions Energy is the capacity to do work Potential energy Kinetic energy Chemical energy Law of conservation of energy – energy can neither be created nor destroyed but it can be converted from one form to another. Total amount of energy at the beginning and end of a reaction are the. Energy Transfer Activation energy Influenced by temperature and concentration Catalysts The Effect of Body Temperature on Enzyme Activity Energy Transfer Exergonic reactions Endergonic reactions Coupled reactions  Endergonic reactions Require energy to be added to do something useful i.e. Exergonic reactions Release energy i.e. Coupled reactions Liberation of energy in an exergonic reaction drives an endergonic reaction The Breakdown of Glucose: Coupled Reactions The energy given off by the exergonic reaction powers the endergonic reaction Main Types of Chemical Reactions Synthesis Reactions - Anabolism When two or more ions, atoms or molecules combine to form new and larger molecules (Building Up) Decomposition Reactions - Catabolism When large molecules are split into smaller atoms, ions, atoms or molecules (Breaking Down) Inorganic vs. Organic Compounds Inorganic compounds usually lack carbon and are simple molecules o Water is the most important and abundant inorganic compound in all living things Organic compounds always contain carbon, usually contain hydrogen, and always have covalent bonds Metabolism of Proteins, Carbohydrates, and Fats Carbohydrates Comprised of carbon, hydrogen and oxygen Include sugars, glycogen, starches and cellulose Main source of chemical energy 2-3% of total body mass Major Carbohydrate Groups (1 of 2) Carbohydrates provide most of the energy needed for life Type of Carbohydrate Examples Monosaccharides (simple sugars Glucose (the main blood sugar). that contain from 3 to 7 carbon Fructose (found in fruits). atoms) Galactose (in milk sugar). Deoxyribose (in DNA). Ribose (in RNA). Disaccharides (simple sugars Sucrose (table sugar) = glucose + formed from the combination of fructose. two monosaccharides by Lactose (milk sugar) = glucose + dehydration synthesis) galactose. Maltose = glucose + glucose. Monosaccharides Major Carbohydrate Groups (1 of 2) Carbohydrates provide most of the energy needed for life Type of Carbohydrate Examples Monosaccharides (simple sugars Glucose (the main blood sugar). that contain from 3 to 7 carbon Fructose (found in fruits). atoms) Galactose (in milk sugar). Deoxyribose (in DNA). Ribose (in RNA). Disaccharides (simple sugars Sucrose (table sugar) = glucose + formed from the combination of fructose. two monosaccharides by Lactose (milk sugar) = glucose + dehydration synthesis) galactose. Maltose = glucose + glucose. Disaccharides Major Carbohydrate Groups (2 of 2) Carbohydrates provide most of the energy needed for life Type of Carbohydrate Examples Polysaccharides (from tens to Glycogen (stored form of hundreds of monosaccharides carbohydrates in animals). joined by dehydration synthesis) Starch (stored form of carbohydrates in plants and main carbohydrates in food). Cellulose (AKA fiber; part of cell walls in plants that cannot be digested by humans but aids movement of food through intestines). Polysaccharides Types of Lipids in the Body (1 of 3) Type of Lipid Functions Fatty acids Used to synthesize triglycerides and phospholipids or catabolized to generate adenosine triphosphate (ATP). Triglycerides (fats and Protection, insulation, energy storage. oils) Phospholipids Major lipid component of cell membranes. Fatty Acids Fatty acids can be saturated or unsaturated  Omega 3 Fatty Acids Polyunsaturated (flax, canola & olive oils, seafood) EPA (eicosapentaenoic acid) DHA (docosahexaenoic acid) ALA (α- linolenic acid) Several health benefits - decrease inflammation - increase muscle protein synthesis pathways - increases oxygen delivery to heart during exercise - increase nerve conduction velocity Omega-3 and Omega-6 Fatty Acids Critical Thinking: Fish Consumption and Heart Disease Meta-analysis of fish Relative Risk for Death from Heart consumption and heart disease Disease (95% Confidence 11 prospective cohort studies Fish Consumption Interval) (222,364 individuals) Less than 1 1 serving/month Participants free of disease at 1–3 servings/month 0.89 (0.79–1.01) beginning, and followed for 12 1 serving/week 0.85 (0.76–0.96) years 2–4 servings/week 0.77 (0.66–0.89) Fish consumption assessed via 5 or more 0.62 (0.46–0.82) food frequency questionnaire, servings/week and number of deaths from heart disease recorded Authors’ conclusion: fish intake is associated with reduced risk of death from heart disease Types of Lipids in the Body Type of Lipid Functions Fatty acids Used to synthesize triglycerides and phospholipids or catabolized to generate adenosine triphosphate (ATP). Triglycerides (fats and Protection, insulation, energy storage. oils) Phospholipids Major lipid component of cell membranes. Triglycerides Triglycerides are the major form of lipid in food and in the body. Triglycerides consist of three fatty acids attached to a glycerol molecule. Triglycerides Types of Lipids in the Body Type of Lipid Functions Fatty acids Used to synthesize triglycerides and phospholipids or catabolized to generate adenosine triphosphate (ATP). Triglycerides (fats and Protection, insulation, energy storage. oils) Phospholipids Major lipid component of cell membranes. Phospholipids Phospholipids are an important component of cell membranes Types of Lipids in the Body Type of Lipid Functions Steroids: Cholesterol Minor component of all animal cell membranes; precursor of bile salts, vitamin D, and steroid hormones. Steroids: Bile salts Needed for digestion and absorption of dietary lipids. Steroids: Vitamin D Helps regulate calcium level in body; needed for bone growth and repair. Steroids: Help regulate metabolism, resistance to stress, Adrenocortical and salt and water balance. hormones Steroids: Sex Stimulate reproductive functions and sexual hormones characteristics. Steroids Types of Lipids in the Body Type of Lipid Functions Eicosanoids Have diverse effects on modifying responses to (prostaglandins and hormones, blood clotting, inflammation, leukotrienes) immunity, stomach acid secretion, airway diameter, lipid breakdown, and smooth muscle contraction. Other lipids: Needed for synthesis of vitamin A (used to Carotenes make visual pigments in eye); function as antioxidants. Other lipids: Vitamin E Promotes wound healing, prevents tissue scarring, contributes to normal structure and function of nervous system, and functions as antioxidant. Other lipids: Vitamin K Required for synthesis of blood-clotting proteins. Other lipids: Transport lipids in blood, carry triglycerides and Lipoproteins cholesterol to tissues, and remove excess Amino Acids Amino acids are the building blocks of protein. Amino Acids Essential (indispensable) amino acids Amino acids that cannot be synthesized by the human body in sufficient amounts to meet needs and therefore must be included in the diet. Nonessential (dispensable) amino acids Amino acids that can be synthesized by the human body in sufficient amounts to meet needs. Amino Acids TABLE 6.1 Essential (Indispensable) and Nonessential (Dispensable) Amino Acids Nonessential Essential Amino Acids Amino Acids Histidine Alanine Isoleucine Arginine* Leucine Asparagine Lysine Aspartic acid (aspartate) Methionine Cysteine (cystine)* Phenylalanine Glutamic acid (glutamate) Threonine Glutamine* Tryptophan Glycine* Valine Proline* Serine by the Food and Nutrition Board, *These amino acids are considered conditionally essential Institute of Medicine. Tyrosine* Source: Adapted from Dietary Reference Intakes for Energy Carbohydrates, Fiber, Fat, Protein and Amino Acids. Washington, DC: National Academies Press, 2002. Amino Acids Amino acids are the building blocks of protein. Each amino acid contains a central carbon atom bound to a hydrogen atom, an amino group, an acid group, and a side chain. Amino Acids Amino Acid Pool Amino acid pool: All of the amino acids in body tissues and fluids that are available for use by the body. Protein turnover: The continuous synthesis and breakdown of body proteins. Protein Proteins give structure to the body, regulate processes, provide protection, assist in muscle contraction, transport substances, and serve as enzymes Protein Structure Peptide bonds are chemical bonds that link amino acids together. Peptide bonds are formed between the acid group of one amino acid and the nitrogen group of the next amino acid. Dipeptide bonds are formed between two amino acids. Polypeptides are formed between many amino acids (10+). A protein is made of one or more polypeptide chains folded into a three-dimensional shape (determines its ). Summary-Protein Structure Functions of Proteins Type of Protein Functions Structural Form structural framework of various parts of body. Examples: collagen in bone and other connective tissues; keratin in skin, hair, and fingernails. Regulatory Function as hormones that regulate various physiological processes; control growth and development; as neurotransmitters, mediate responses of nervous system. Examples: the hormone insulin (regulates blood glucose level); the neurotransmitter known as substance P (mediates sensation of pain in nervous system). Contractile Allow shortening of muscle fibers (cells) which produces movement. Examples: myosin; actin. Functions of Proteins Type of Protein Functions Immunological Aid responses that protect body against foreign substances and invading pathogens. Examples: antibodies; interleukins. Transport Carry vital substances throughout body. Example: hemoglobin (transports most oxygen and some carbon dioxide in blood). Catalytic Act as enzymes that regulate biochemical reactions. Examples: salivary amylase; sucrase; ATPase. Nitrogen Balance Nucleic Acids DNA forms the genetic code in the nuclei of body cells and it regulates most of the cell’s activities RNA guides protein formation Components of a Nucleotide DN A  DNA vs. RNA Feature DNA RNA Nitrogenous bases Adenine (A), cytosine Adenine (A), cytosine (C), guanine (G), (C), guanine (G), uracil thymine (T). (U). Sugar in nucleotides Number of strands Two (double-helix, like a One. twisted ladder). Nitrogenous base A with T (2), G with C A with U (2), G with C pairing (number of (3). (3). hydrogen bonds) How is it copied? Self-replicating. Made by using DNA as a blueprint. Function Encodes information for Carries the genetic code making proteins. and assists in making proteins. Types Nuclear, mitochondrial. Messenger RNA (mRNA), transfer Adenosine Triphosphate (AT P) A T P is the principal energy-storing molecule in the body How Does The Cell INITIALLY and RAPIDLY resynthesize ATP?  Consumed in the diet Nitrogen-containing (red meat, seafood) compound (arginine, Synthesized in and/or through glycine, methionine) supplementation What are other ways the cell can resynthesize ATP? Cellular respiration is when carbohydrates, lipids and proteins are catabolized Releases energy to attach phosphate to ADP to produce ATP Two phases o Anaerobic (without oxygen); glucose partially broken down into pyruvic acid; yields 2 ATP. o Aerobic (requires oxygen); glucose, lipids and protein broken into CO2 and H2O); yields 32 ATP.