Please enable JavaScript.
Coggle requires JavaScript to display documents.
Nutrition, Metabolism & energy balance, Metabolism:
sum of all the…
Nutrition, Metabolism & energy balance
Metabolism:
- sum of all the body's chemical reactions (Key Terms)
- It will vary depending on age, sex, activity level ,fuel consumption, and lean body mass. (Ch. 24 intro)
- Basal Metabolic rate, the amount of energy expended by the body at rest and basic daily activity. (Key Terms)
- Men tend to have a higher BMR compared to women because their lean muscle is greater (CH. 24 Intro)
Anabolism:
- Assembly of more complex molecules from simpler molecules (Key Terms)
- The body assembles these chemicals by combining small molecules that come from the foods we eat. (1.3)
Catabolism:
- Breaking down of more complex molecules into simpler molecules (Key Terms)
- Complex molecules found in foods are broken down so the body can use these parts to assemble structures and substances need for life (1.3)
Oxidation-reduction Reactions (Redox Reaction):
- Pair of reactions in which an electron is passed from one molecule to another, oxidizing one and reducing the other (Key terms)
- These reactions will happen in a series; as it progresses, energy accumulates to form ATP (24.1)
- Catalyzed by enzymes that trigger the removal of hydrogen atoms (24.1)
- common enzymes of redox reaction include Nicotinamide Adenine Dinucleotide (NAD) and Flavin Adenine Dinucleotide (FAD) (24.1)
Carbohydrate Metabolism:
- Carbohydrates are broken down into simple structures, like sugars, so it can be used as energy
Glycolysis:
- A series of metabolic reactions that break down glucose into pyruvate and produces ATP (Key terms)
- One molecule breaks down into 2 pyruvate molecules, creating 2 net ATP molecules and 2 NADH molecules (24.2)
Citric Acid Cycle (Krebs cycle / Tricarboxylic Acid Cycle):
- Converts pyruvate into CO2 and high energy FADH2, NADH, and ATP molecules (Key terms)
-Citrate synthase combines with Acetyl CoA and oxaloacetate to form a 6-carbon citrate molecule. (24.2)
- The Aconitase enzyme converts citrate into isocitrate, which then produces CO2 and 2 NADH via isocitrate dehydrogenase, this also converts isocitrate into the 5-carbon alpha-ketoglutarate. It is will be catalized and converted into 4-carbon succinyl CoA. (24.2)
- Succinyl CoA dehydrogenase converts to succinyl Coa into succinate, forming high-energy GTP, tranfering its energy to ADP to produce ATP. Succinate dehydrogenase will convert to fumarate to form FADH2(24.2)
- Fumarase > malate > converts back to Oxaloacetate, reducing NAD+ to NADH
- Oxaloacetate can start the Cycle again
Electron Transport Chain (ETC) & Oxidative Phosphorylation:
- ETC - ATP production pathway in which electrons are passed through a series of oxidation-reduction reactions that forms water and produces a proton gradient (Key Terms)
- utilizes NADH and FADH2 produced by the citric acid cycle (24.2)
- consist of 4 enzyme, Complex I - IV, and ubiquinone and cytochrome, 2 coenzymes (24.2)
- this process couples the transfer of electrons between a donor and an electron acceptor with the transfer of protons across the inner mitochondrial membrane (24.2)
- Oxidative Phosphorylation is the process that converts high energy NADH and FADH2 into ATP (Key Terms)
- Energy is passed through electron carriers, oxygen is present, gradually collecting energy needed to attach a phosphate to ADP and produce ATP (24.2)
- molecular oxygen acts as a terminal electron acceptor for ETC (24.2)
Absorptive State:
- The metabolic state occurring during the first few hours after ingesting food in which the body is digesting food and absorbing the nutrients (Key terms)
- Lingers for up to 4 hours (24.5)
- Pancreatic beta cells are stimulated and release insulin into the blood stream, initiating the absorption of blood glucose by hepatocytes, adipose, and muscle cells (24.5)
Carbohydrates:
- broken down in the mouth; it's individual components are transported across the intestinal wall and enters the bloodstream or lymphatic systems (24.5)
Triglycerides:
- Digested and absorbed into the lymphatic system (24.5)
- Transported to adipose tissue for storage (24.5)
Amino Acids:
- transported across the intestinal wall and enters the bloodstream
- Insulin will cause the synthesis of protein in muscle (24.5)
Micronutrients:
- Vitamins and minerals; these elements and compounds participate in many essential chemical reactions and processes such as nerve impulses and body structures. (1.4)
Vitamins:
- Organic compounds required by the body to perform biochemical reactions like metabolism and bone, cell, and tissue (key Terms)
- we get most of our vitamin's through diet, but some can be formed from precursors absorbed during digestion (24.7)
- Excess vitamin retained in the lipid stores in the body can result in hypervitaminosis. (24.7)
Minerals:
- Inorganic compounds required by the body to ensure proper function of the body (Key Terms)
- Cannot be made in the body; instead, they come from diet (24.7)
- only 4% of the total body mass amounts to minerals in the body (24.7)
- Calcium and phosphorous are some of the common minerals, which are stored in the skeleton, necessary for hardening bones (24.7)
Lipid Metabolism:
- The oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules (24.3)
- associated with Carbohydrate metabolism since glucose can be converted into lipids (24.3)
Lipolysis:
- The breakdown of Triglycerides into glycerol and fatty acids (Key terms)
9 takes place in the cytoplasm (24.3)
- Triglycerides are broken down by hydrolysis, becoming fatty acids and glycerol. (24.3)
- fatty acids are oxidized by Beta-oxidation into acetyl CoA. (24.3)
- The Glycerol released enters the glycolysis pathway as DHAP. (24.3)
Lipogenesis:
- synthesis of lipids that occurs in the liver or adipose tissues (Key Terms)
- lipids are created from acetyl CoA and takes places in the cytoplasm of adipocytes and hepatocytes (24.3)
- Acetyl CoA + 2 carbon atoms from another acetyl CoA begins lipogenesis, repeating until fatty acids are at appropriate length (24.3)
Post Absorptive State:
- The fasting state, occurs when the food has been digested, absorbed, and stored. (24.5)
- Food is no longer the body's source of energy, so it must rely on stored glycogen (Key Terms)
- Glucose levels drop as it's absorbed by cells; insulin drops in response to the decrease in glucose (24.5)
Glucose Sparing:
- GH stimulates lipolysis resulting in many tissues using fatty acids as their main energy source. (17.3)
Sources of Blood Glucose:
- Glucagon released from alpha cells of the pancreas stimulate the breakdown of glycogen back into glucose. Blood glucose levels begin to rise (24.5)
Glycogenolysis In the Liver:
-Glucagon released from the pancreas, acts upon liver cells, inhibiting the synthesis of glycogen and stimulates the breakdown of stored glycogen back into glucose. (24.5)
-
Lipolysis in Adipose Tissue & the Liver:
- glycogen and triglyceride storage slows
- excess glucose absorbed from the liver will be converted into triglycerides and fatty acids for long term use (24.5)
-
Hypothalamus:
- responsible for coordinating autonomic and endocrine function of homeostasis (Key Terms)
Regulatory Centers:
- thermoregulation, maintains the body at its core temperature. If too high, it can increase circulation of the blood to the surface of the body to dissipate heat. If too low, it can cause shivering to increase body heat. (24.6)
Afferent Input:
- Leptin is secreted by adipose tissue in response to food consumption, The hypothalamus receives these signals, promoting satiety. (Key Terms)
- suprachiasmatic nucleus - a hypothalamic target of the retina that help establish the circadian rhythm of the body on the basis of daylight (Key terms)