Transcript CHAPTERS 23-25

CHAPTERS 23-25
CONCURRENT ENROLLMENT
CARBOHYDRATE
METABOLISM
 45% to 55% of the daily energy needs come
from carbohydrates in the American diet
 During digestion the di- and polysaccarides are
hydrolyzed into glucose, fructose and galactose
 After digestion these monosaccarides are
absorbed into the blood system through the
small intestines and transported to the liver
 Blood sugar
 The amount of glucose present in blood,
normally expressed as milligrams per 100 mL
of blood
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 Hypoglycemia
 A lower-than-normal blood sugar level
 Hyperglycemia
 higher-than-normal blood sugar level
 Renal threshold
 The blood glucose level at which glucose begins to
be excreted in the urine
 Glucosuria
 A condition in which elevated blood sugar levels
result in the excretion of glucose in the urine
 Glycolysis
 A series of reactions by which glucose is oxidized to
pyruvate
 Page 713
 A net gain of 2 mol of ATP is form for 1 mole of
glucose and 2 moles of NADH is formed
REGULATION OF
GLYCOLYSIS
 Lactose intolerance
 The inability to digest milk and other products
containing lactose
 The glycolytic pathway is regulated by three enzymes
 Hexokinase, phosphofructokinase, and pyruvate
kinase
 Phosphorylation of glucose is a feedback inhibition
 The second enzyme is an allosteric enzyme - high
conc. of ATP and citrate inhibit it, while high conc. of
ADP and AMP activate it
 The last step has the third enzyme which is also an
allosteric enzyme -high conc. of ATP inhibits it
Fates of pyruvate
 Aerobic
 In the presence of oxygen
 Forms acetyl CoA and NADH
 Anaerobic
 In the absence of oxygen
 Forms lactate and NAD+
 Lactate fermentation
 The production of lactate from glucose
 In anaerobic conditions not enough energy is formed,
not enough oxygen
 Alcoholic fermentation
 Pyruvate in two steps form ethanol
 Overall reaction the glucose forms ethanol and 2 ATP
 Figure 23.5 page 717
CITRIC ACID CYCLE
 Summary
 Acetyl CoA is the fuel of the cycle
 Requires a supply of NAD+ and FAD
 Two carbon atoms enter the cycle as an acetyl unit
and two carbon atoms leave the cycle as CO2
 In one cycle four redox reactions produce 3 NADH
and 1 FADH2
 One molecule of GTP is generated
 Fig 23.7 page 719
 Citrate synthetase is an allosteric enzyme that is
inhibited by ATP and NADH and activated by ADP
ELECTRON TRANSPORT
CHAIN
 A series of reactions in which protons and electrons from
the oxidation of foods are used to reduce molecular
oxygen to water
 Cytochrome
 An iron-containing enzyme located in the electron
transport chain
 Fig 23.9 page 721
 Oxidative phosphorylation
 A process coupled with the electron transport chain
whereby ADP is converted to ATP
 ATP is synthesized at three sites within the electron
transport chain
 The entire catabolic pathway generates 10 ATP
molecules for every 1 acetyl CoA
 Read pages 724-730 will be on test
CHAPTER 24
 Figure 24.1 page 738
 Behavior of blood lipids parallels that of blood sugar
 One general method of classifying lipoproteins is by
density
 LDL (less and 0.95 g/mL) and HDL (1.06-1.21 g/mL)
 Chylomicron
 A lipoprotein found in the lymph and the bloodstream
 Red blood cells cannot oxidized fatty acids, when body
cells need fatty acids for energy, the endocrine system
produces hormones which interact with adipose tissue
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 Adipose tissue
 A kind of connective tissue where triglycerides are
stored
 Fat mobilization
 The hydrolysis of stored triglycerides, followed by the
entry of fatty acids and glycerol into the bloodstream
 Oxidation of fatty acids
 Cannot be oxidized to produce energy until they pass
through the mitochondrial membrane
 ß-oxidation process - a pathway in which fatty acids are
broken down into molecules of acetyl CoA
 Four reactions are involved in oxidizing the -carbon to a
ketone page 743
 Net on page 744
Ketone bodies
 Lipids are 25% more efficient than
carbohydrates in storing energy
 Lipids contain twice the energy of
carbohydrates
 Ketone bodies
 Three compounds - acetoacetate, ß-hydroxybutyrate,
and acetone - formed from acetyl CoA
 Ketone bodies are carried by the blood to body
tissues, mainly the brain, heart, and skeletal muscle,
where it is oxidized
 Ketonemia
 An elevated level of ketone bodies in the blood
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 Ketonuria
 The presence of ketone bodies in the urine
 Acetone breath
 A condition in which acetone can be detected in the
breath
 Ketosis
 A condition in which ketonemia, ketonuria, and
acetone breath exist together
 Acidosis
 Low blood pH
 Ketoacidosis
 Low blood pH due to elevated levels of ketone bodies
FATTY ACID SYNTHESIS
 When more nutrients are brought in than
needed the excess is not excreted but
converted into fatty acids and then to body fat read pages 747-748 about this
 Amino acid metabolism
 75% of the amino acids are used to
synthesis protein in a health body
 Protein turnover- the continuing process in
which body proteins are hydrolyzed and
resynthesized
 Figure 24.7 page 750
 Read pages 750-759 will be on the test
CHAPTER 25
 Intracellular fluid
 Body fluid located inside cells
 Extracellular fluid
 Body fluid located outside cells
 Interstitial fluid
 The fluid surrounding individual tissue cells
 Make up 20% of the total body fluid
 Plasma
 The liquid portion of the whole blood
 Makes up 7% of the total
 Principal cation of plasma and interstitial fluid is Na+, K+
is found in the intracellular
 Principal anion in extracellular is Cl- and phosphate
inside cell
 Intracellular fluid contains 4 times more protein and in
plasma
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 About 98% of the needed oxygen is carried by red
blood cells
 Oxyhemoglobin - a oxygen-hemoglobin form
 Deoxyhemoglobin - nonoxygenated hemoglobin
 Carbaminohemoglobin - combined with carbon dioxide
- about 25% of the carbon dioxide is carried from the
body tissues to the lungs this way
 The remaining 70% is transported in the form of HCO3 Go over the chloride shift pages 769-770
CONSTITUENTS OF URINE
 Urine is made up of 96% water and 4% dissolved
organic and inorganic waste
 The pH of a healthy person’s urine is 4.5-8.0
 Table 258.1 page 772
 The body is made up of 45-75% water
 Fluid and electrolyte balance are interdependent
 Most hospital patients have fluid and electrolyte balance
therapy
 The output and intake must be equal
 Water normally leaves the body through the kidneys
(urine, lungs, skin, and intestines (feces))
 Vesopressin, ADH, increases the absorption of the renal
tubules in the kidneys (water goes back into the
bloodstream)
ACID-BASE BALANCE
 Blood pH has to be 7.35-7.45
 Death can occur if the pH goes above 7.8 and below
6.8
 Alkalosis
 High blood pH
 Acidosis
 Low blood pH
 There are three buffer systems in the blood
 Bicarbonate buffer, phosphate buffer, and plasma
proteins
 Buffers neutralize H+ and OH Respiratory system control pH by carbonic acid
 Hyperventilation - rapid, deep breathing
 Hypoventilation - slow, shallow breathing
URINARY CONTROL OF pH
 Page 777
 Acidosis and alkalosis page 777-780
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