Chapter 25 Notes Continued
Metabolism

Glucose Anabolism

5. GlucosE is the preferred molecule for cellular respiration. Help comes from the three "G’s"

• GLYCOGENESIS,
• GLYCOGENOLYSIS
• GLUCONEOGENESIS
• these are under the control of insulin and glucagon
• Insulin
  - reduces blood glucose levels
  - increases cellular uptake of glucose
  - GLYCOGENESIS
  - increases lipogenesis
  - increases protein synthesis
• Glucagon
  - raises blood sugar levels
  - slows cellular uptake of glucose
  - GLYCOGENOLYSIS
  - decreases lipogenesis
  - similar results with epinephrine
• 124 ways to loose your sugar

6. DIABETES MELLITUS

• hyperglycemia
• glucosuria
• polyuria
• polydipsea
• polyphagia
• lipids used to produce ATP increased ketones
• metabolic acidosis
• atherosclerosis
• circulatory problems
• damage to kidneys
• cataracts

Lipid Metabolism

6. Pathway of lipids to liver

• bile emulsifies triglycerides to form water soluble micelles
• hydrolysis by lipase to form fatty acids and monoglycerides
• rearrangement by intestinal mucosa (columnar cells)
• cholesterol, phosopholipids and triglycerides packaged into CHYLOMICRONS
• transport to lacteals, to thoracic duct to subclavian veins to liver

7. Components of lipoproteins: cholesterol

• not an energy source
• 80 % form bile salts
• form steroid hormones
• form stratum corneum of skin
• all about cholesterol online

8. Components of lipoproteins:  phospholipids

• myelin sheath insulates axons
• major donor of phosphate ions
• forms thromboplastin
• part of cell membrane

9. Components of lipoproteins:  triglycerides

• ENERGY RESERVE
• glycerol converted to PGAL
• fatty acids converted to ACETYL COENZYME A

10. Classes and functions of lipoproteins

• very low density lipoproteins
  - from diet
  - transport triglycerides synthesized by liver to adipose tissue and muscle
• low density lipoproteins
  - from diet
  - transport cholesterol to peripheral tissues to form
     steroid hormones, bile, and cell membranes
• high density lipoproteins
  - from genes
  - transport cholesterol from tissues to liver where it is catabolized into bile
• online LDL's and HDL"s

11. Lipid Catabolism: Beta Oxidation

• fatty acids are converted to acetyl coenzyme A to enter glucose oxidation for ATP
• three acid products called KETONES

- acetone
- acetoacetic acid
- b hydroxybutyric acid

• these accumulate with a lipid rich meal, fasting or starvation,
  no carbohydrates in diet, diabetes mellitus
• leads to ketosis
  - increased ketones in blood
  - fall in pH
  - metabolic acidosis
  - dehydration

Protein Metabolism

12. Protein synthesis

• amino acids are used by all cells for transcription and translation
• body can synthesize 12 amino acids through the Krebs cycle, these are non-essential amino acids
• body requires in diet 8 amino acids, these are essential amino acids
• 20 amino acids online

13. Protein deamination

• amino acids can be converted into the acids of the Krebs Cycle
• the process removes the amino group-DEAMINATION
• NH2 remnant is processed by the liver to form urea