Urinary System

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I. Objectives
A. Define energetics and metabolism and explain why cells must synthesize new organic components. B. Differentiate between the absorptive and postabsorptive metabolic states, and summarize the characteristics of each. C. List the metabolic processes of the liver.

D. Summarize the mechanisms of lipid transport and distribution. E. Discuss the use of proteins as an energy source.
F. Define metabolic rate, discuss the factors involved in determine an individual’s BMR, and discuss the homeostatic mechanisms that maintain a constant body temperature.

Energetics –Is the flow of energy and its changes from one form to I. another

II. Metabolism - Refers to all chemical reactions in an organism

A. Introduction to Terms –

1. Anabolism – Is the synthesis of new organic molecules,is an “uphill” process that forms new chemical bonds. III. chemical bonds

1. Catabolism – Is the breakdown of organic substrates, Releases energy used to synthesize high-energy compounds (e.g., ATP)

ATP – • Oxidative Phosphorylation
• Is the generation of ATP
• Within mitochondria
• In a reaction requiring coenzymes and oxygen
• Produces more than 90% of ATP used by body
• Results in 2 H2 + O2 → 2 H2O
• Electron Transport System (ETS)
• Is the key reaction in oxidative phosphorylation
• Is in inner mitochondrial membrane
• Electrons carry chemical energy
• Within a series of integral and peripheral proteins
• Oxidation, Reduction, and Energy Transfer
• Oxidation (loss of electrons)
• Electron donor is oxidized
• Reduction (gain of electrons)
• Electron recipient is reduced
• The two reactions are always paired
• Energy Transfer
• Electrons transfer energy
• Energy performs physical or chemical work (ATP
formation)
• Electrons
• Travel through series of oxidation–reduction
reactions
• Ultimately combine with oxygen to form water

• Coenzymes
• Play key role in oxidation–reduction reactions
• Act as intermediaries
• Accept electrons from one molecule
• Transfer them to another molecule
• In citric acid cycle:
• Are NAD and FAD
• Remove hydrogen atoms from organic substrates
• Each hydrogen atom consists of an electron and a
proton
• Oxidation–Reduction Reactions
• Coenzyme
• Accepts hydrogen atoms
• Is reduced
• Gains energy
• Donor molecule
• Gives up hydrogen atoms
• Is oxidized
• Loses energy
• Oxidation–Reduction Reactions
• Protons and electrons are released
• Electrons
• Enter electron transport system
• Transfer to oxygen
• H2O is formed
• Energy is released
• Synthesize ATP from ADP
• Proteins and ATP Production
• When glucose and lipid reserves are inadequate, liver
cells:
• Break down internal proteins
• Absorb additional amino acids from blood
• Amino acids are deaminated
• Carbon chains broken down to provide ATP

Kilocalorie – • Energy required to raise 1 kilogram
of water 1 degree Celsius is a Calorie (Cal) =
1. kilocalorie (kcal)

Organic Molecules –Functions of Organic Compounds
1. Perform structural maintenance and repairs
2. Support growth
3. Produce secretions
4. Store nutrient reserves

Glycogen
Organic Compounds
• Glycogen
• Most abundant storage carbohydrate
• A branched chain of glucose molecules
• Triglycerides
• Most abundant storage lipids
• Primarily of fatty acids
• Proteins
• Most abundant organic components in body
• Perform many vital cellular functions

IV. Metabolic Interactions
A. Absorptive State – Look at page 936-937 in your text book and answer the following questions.

Define absorptive state –That period of time in the body during which cell metabolism is primarily fueled by nutrients derived by absorption from the most recent meal; this state is dominated by insulin release from the beta cells of the pancreatic islets in response to hyperglycemia; most cells in the body are responsive targets to...
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