Lecture_25_Digestive 2.pptx

GENERAL BIOLOGY II Lecture 25: Digestive System & Metabolism Chapter: 34 Metabolism Adenosine Triphosphate (ATP) – the basic biologically available chemical used for energy storage Metabolism Two types of reactions associated with metabolism: Catabolic – metabolic pathways that break down molecules...

GENERAL BIOLOGY II Lecture 25: Digestive System & Metabolism Chapter: 34 Metabolism Adenosine Triphosphate (ATP) – the basic biologically available chemical used for energy storage Metabolism Two types of reactions associated with metabolism: Catabolic – metabolic pathways that break down molecules into smaller units to either release energy or for use in anabolic reactions Anabolic – metabolic pathways that construct macromolecules like DNA from smaller subunits Metabolism The breakdown of glucose: Anerobic metabolism Aerobic metabolism Metabolism Anerobic metabolism Occurs in the cytosol of the cell Results in: Pyruvate x2 ATP x2 NADH x2 Pyruvate can be fermented into lactic acid Metabolism Aerobic metabolism Occurs in the mitochondria Puts pyruvate through the Citric Acid Cycle Results in: NADH FADH2 Electron transport chain produces: ~ATP x32 Water Metabolism Metabolic Rate – Measured by how much oxygen the animal consumes within a given amount of time C6H12O6 + 6O2 ⟶ 6H2O + 6CO2 + ATP Metabolism Metabolic Rate – The overall rate of an animal’s energy use Measured by how much oxygen the animal consumes within a given amount of time C6H12O6 + 6O2 ⟶ 6H2O + 6CO2 + ATP Metabolism Oxygen demand is dependent on activity level Shift from resting to active requires an immediate source of energy (anerobic respiration) Creates an oxygen debt once initial energy stores in the muscles are depleted Metabolism Oxygen demand is dependent on activity level As activity shifts continues for an extended period of time, energy needs are met by aerobic respiration, met by an increased metabolic rate Metabolism Oxygen demand is dependent on activity level After activity ceases, metabolic rates slowly return to resting Recovery metabolism – elevated rate of oxygen consumption following activity Metabolism Oxygen demand is also dependent on body mass Metabolic rate increases by mass raised to the ¾ power Each g of body mass consumes less energy in larger organisms compared to smaller ones Metabolism Oxygen demand is also dependent on body mass The energetic cost of moving is greater for smaller animals than larger ones Diet Energy balance – Energy Intake vs. Energy Use over a given period of time Generally, energy intake balances energy use to maintain homeostasis Diet About 70% of energy use is accounted for by basic life processes Food consumption & digestion Respiration & Circulation Maintaining homeostasis Physical activity accounts for the other 30% Diet Animals that take in more than they use increase their body weight Regular repetition results in obesity Using more energy than one takes in reduces body weight Regular repetition results in malnourishment Diet Essential Amino Acids – those amino acids that an organism cannot synthesize from others that they consume Which vary from species to species Most animals can synthesize about half of their amino acids Feeding Adaptations Methods of Feeding: Suspension filter feeding – allows animal to strain suspended food particles from water Suction feeding – allows animal to change environmental pressure to force food into mouth Jaws & teeth – allows animal to bite and chew Feeding Adaptations Suspension filter feeding – water is passed through a sievelike structure to trap small suspended particles or animals Feeding Adaptations Suction feeding – rapid expansion of the oral cavity creates a vacuum that pulls animals into the mouth Feeding Adaptations Jaw Temporomandibular joint – joint that connects the lower jaw to the skull Allows food to be mechanically broken down before being swallowed Feeding Adaptations Teeth Specialized teeth evolved to be arranged to efficiently process the animal’s diet Feeding Adaptations Teeth Types of teeth Incisors – specialized for biting Canines – specialized for piercing prey Premolars & Molars – adapted for crushing and shredding tougher food For Next Class Complete the Quiz on CANVAS Read The rest of Chapter 34: Digestive System & Metabolism Read The rest of Chapter 41: The Renal System