Ch 25 - Nutrition, Metabolism, Temp Reg

Term
1 / 53
Nutrients
Click the card to flip 👆
Terms in this set (53)
Nutrients
Chemicals taken into the body to produce energy provide building blocks for new molecules, and to function in chem reactions
Essential Nutrients
Cannot be manufactured in the body in adequate amounts, so they must be ingested
(vitamins, minerals)
Energy supplies by food is measured in
kilocalories
Nutrients Include
Carbs, lipids, proteins, vitamins, minerals, water
Carbs
Dietary sources are mostly plants, except for lactose
Used for energy
Lipids
Triglycerides, cholesterol, phospholipids
Dietary sources include meat, fish, milk fats and plant oils
Used for energy and cell membrane
Proteins
Dietary sources include meat, fish, dairy, vegs
Used in protection, regulation, structure (collagen), muscle contraction, transport (hemoglobin)
Vitamins
Organic molecules essential to normal metabolism, present in minute quantities in foods. A balanced diet is necessary to obtain all essential vitamins
Fat Soluble Vitamins
May be stored in the body even to excessive, toxic levels (A, D, E, K)
Water Soluble Vitamins
Quickly excreted in urine (B, C, rest)
MineralsInorganic nutrients necessary for normal metabolism, absorbed from animal and plant sources.WaterClassified as a nutrient because it is necessary for transport, for dissolving substances, for its involvement in various metabolic reactions, and for body temp regulationMetabolismTotal of all chemical changes that occurCatabolismBreak down molecules, releases energyAnabolismForms larger molecules, requires energy inputEnergy released from food molecules is used to buildATPNAD+ and FAD+ function asTemporary high energy electron carriers, transporting electrons to electron carriers of ETC for production of ATPGlycolysisbreaks down a single glucose molecule to 2 pyruvic acids. Takes place in cytoplasm of cell INPUTS: 1 glucose, 2 ATP, 2 NAD+ OUTPUT: 2 pyruvic acid, 4 ATP (net gain of 2), 2 NADH 0 co2, 0 FADH2What do you need to get glucose from blood into the cell?Insulin because it directly phosphorylatesSteps of GlycolysisC6H12O6 Directly phosphorylates PC6H12O6P - 2 ATP -2 H = + 2 NADH C6H10 Splits to C3H5 Pyruvic acid +2ATPLactic Acid FermentationTakes place in cytoplasm of cells INPUT: 2 pyruvic acid +2 NADH OUTPUT: 2 lactic acidLactic acid is ____ from the cells that produce it and transported by the bloodstream to the _____.Released Liver It can be converted to glucose in the liver by use of ATPProcesses involved in aerobic respirationGlycolysis Acetyl coA formation Citric Acid Cycle / Krebs ETCAcetyl CoA Formation / TransitionTakes place in inner compartment/ matrix of mitochrondria INPUT: 2 pyruvic acid, 2 NAD+ OUTPUT: 2 NADH, 2 CO2, 2 Acetyle CoA, 0 ATP 0 FADH2Steps of Acetyle CoA FormationC3H5 take out NADH C3H4 take out CO2 C2H4 +CoACitric Acid Cycle / Krebs CycleINPUT: 2 acetyle coA molecules, 6 NAD+, 2 FAD+ OUTPUT: 6 NADH, 2 FADH2, 4 CO2, 2 ATPWhere does the krebs cycle take place?Matrix of the mitochondriaElectron Transport Chaine- and H+ released from NADH and FADH2 supply energy to build ATP by the process chemiosmosis, using the enzyme ATP synthase INPUT: 2 NADH from glycolysis, 2 NADH from acetyl coA form, 6 NADH from citric acid cycle, 2 FADH2 from citric acid OUTPUT: 8 NAD+, 2 FAD, 32 ATPFor every NADH2 or 3 ATPS producedFor every FADH22 ATPS producedETC takes place inEmbedded in cristae of mitochondrial membraneAerobic respiration produces _____ ATP per glucose moleculeACTUAL 36 (2 from glycolysis, 2 from citric acid cycle, 32/4 from ETC)Why is actual production of ATP less than theoretical predictions-Numbers of ATP produced during ETC are no consistent in all tissues -An energy cost to shuttling NADH from glycolysis into mitochondria -There is an energy cost to shuttling reactants for ATP production (ADP and phosphates) into the mitochondriaWhat are the body's primary energy storage molecule?LipidLipids are stored astriglycerides in adipose tissue and released into the bloodstream when needed (between meals)Lipid Metabolism1. Stored triglycerides are broken down and released as free fatty acids 2. Free fatty acids are taken up by cells and metabolized by the process of beta oxidation to form acetyle CoA 3. Acetyl CoA can enter the Krebs cycle and be used to generate ATP 4. Acetyle CoA can also produce ketone bodies. Excessive amounts cause the condition metabolic acidosis which can result in life threatening acidosis of the bloodAmino acids are used in the body's cells primarily tosynthesize proteins Secondarily they may serve as a source of energyWhat are the 2 ways AA are converted to energy sources?1) Oxidative Deamination- amine group is removed from the AA, producing ammonia and a keto acid and reducing a molecule of NAD+ to NADH. 2) Conversion to a keto acidGlycogenesisFormation of glycogen from glucoseLipogenesisFormation of lipids from glucose or proteinsGlycogenolysisThe breakdown of glycogen to glucoseGluconeogenesisFormation of new glucose from AA or glycerolAbsorptive StateLasts about 4 hours immediately after a meal when nutrients are used as energy or storedPost Absorptive StateOccurs many hours after a meal typically after the conclusion of each absorptive state (late morning, late afternoon, overnight). Stored nutrients are used for energy.Metabolic RateTotal energy expenditure per unit of time A person will gain or lose weight if energy used is greater than energy input3 Contributing Factors to Metabolic Rate1) Basal metabolic rate: energy used at rest 2) Thermic effect of food: energy used to digest food 3) Muscular Activity: energy used for muscle contractionBody Mass IndexStandard for assessing body weight wt (kg) / Ht^2 (in meters)BMI > _____ is categorized as overweight25 - 27BMI > is catergorized asobeseBMI < _____ is categorized as under weight18.5Body tempbalance between heat gain and heat loss Regulated by a set point in hypothalamusHeatProduced by metabolic rxns in body Exchanged with the environment by radiation, convection, conduction, and evaporationThe greater temp difference between the body and the environment,the greater the rate of heat exchange